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    <title>iOS/Android [ChaosOverFlow]</title>
    <description>iOS Android ChaosOverFlow Chat room site. Source for iOS and Android beginner tutorials.
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    <link>http://shubhank101.github.io/iOSAndroidChaosOverFlow/</link>
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    <pubDate>Fri, 02 Sep 2016 23:40:33 +0530</pubDate>
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      <item>
        <title>Push notification in ios Using fcm (swift)</title>
        <description>&lt;h2 id=&quot;what-is-fcm&quot;&gt;What is FCM?&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;FCM (Firebase Cloud Messaging)&lt;/strong&gt; replaces Google Cloud Messaging (GCM) as the API to send/receive push notifications from.&lt;br /&gt;
Most of the popular apps in the market uses push notifications to engage the user and i am sure you are interested to implement them in your app too so follow along.&lt;/p&gt;

&lt;h3 id=&quot;how-does-fcm-work&quot;&gt;How does FCM work&lt;/h3&gt;

&lt;p&gt;&lt;img src=&quot;https://firebase.google.com/docs/cloud-messaging/images/messaging-overview.png&quot; alt=&quot;FCM Diagram&quot; /&gt;&lt;/p&gt;

&lt;p&gt;As shown in the figure, the FCM is the middle ware between your device and the server.&lt;br /&gt;
You send the message you want to send to the devices to the Firebase server and it redirects it to the appropriate device. It handles all the middle ware part like scheduling notification time, failure and success rate, unique device tokens etc.&lt;/p&gt;

&lt;p&gt;We can use a http/xmpp server to send the message to the FCM server but in our tutorial we use the handy tool provided by the FCM guys - &lt;strong&gt;Notification console&lt;/strong&gt;.&lt;/p&gt;

&lt;hr /&gt;

&lt;h2 id=&quot;theory-of-how-push-notification-work-on-ios&quot;&gt;Theory of how Push notification work on iOS&lt;/h2&gt;

&lt;p&gt;Before progressing to code and FCM working for push notification, we should do a little review of how push notification works.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Apple Push Notification Service (APNS)&lt;/strong&gt; is responsible for managing devices and sending message to them. We can send our push notification payload to the APNS server with the device token and it takes care of scheduling the message as well as success/failure rate.&lt;br /&gt;
Each device is &lt;strong&gt;uniquely identified by its device token&lt;/strong&gt;. Further, an app require user to grant the permission to send push notification to user device. If the user declines - you won’t get a device token and therefore can’t target the user.&lt;/p&gt;

&lt;hr /&gt;

&lt;h2 id=&quot;step-1-asking-permission-for-push-notifications&quot;&gt;Step 1. Asking Permission for push notifications&lt;/h2&gt;

&lt;p&gt;Create a new Xcode Project and name it &lt;strong&gt;FCM_Tutorial&lt;/strong&gt;.&lt;/p&gt;

&lt;p&gt;Now note down the &lt;strong&gt;bundle id&lt;/strong&gt; and store it in a separate place, we will need it to make the &lt;code class=&quot;highlighter-rouge&quot;&gt;GoogleService-Info&lt;/code&gt; plist file later when we add Firebase to our app.&lt;/p&gt;

&lt;p&gt;To get the device token - we need to ask user permission for sending alert, banner and/or sound push.&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/j02xEHm.png?1&quot; alt=&quot;Push Notif&quot; /&gt;&lt;/p&gt;

&lt;p&gt;If user allow, the device will contact the APNS server and a push notification will be passed on to the App delegate function &lt;strong&gt;didRegisterForDeviceToken&lt;/strong&gt;.
Any error if occured is received in the function &lt;strong&gt;didFailtoregister&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Update your AppDelegate’s &lt;code class=&quot;highlighter-rouge&quot;&gt;didFinishLaunchingWithOptions&lt;/code&gt; method with the following code&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;&lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIApplication&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;didFinishLaunchingWithOptions&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;launchOptions&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;NSObject&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;AnyObject&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]?)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&amp;gt;&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Bool&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
     &lt;span class=&quot;c1&quot;&gt;// Override point for customization after application launch.&lt;/span&gt;
     
     &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;notificationTypes&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIUserNotificationType&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;UIUserNotificationType&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Alert&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIUserNotificationType&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Badge&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIUserNotificationType&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Sound&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
     
     &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;notificationSettings&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIUserNotificationSettings&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;forTypes&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;notificationTypes&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;categories&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kc&quot;&gt;nil&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
     &lt;span class=&quot;n&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;registerUserNotificationSettings&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;notificationSettings&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
     &lt;span class=&quot;n&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;registerForRemoteNotifications&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
     
     &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;kc&quot;&gt;true&lt;/span&gt;
 &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
 &lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;We create an array defining the types of notification we need and then call &lt;code class=&quot;highlighter-rouge&quot;&gt;registerUserNotificationSettings&lt;/code&gt; so that the OS ask for the permission from the user.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;You cannot test push notification on simulator so make sure to have a apple dev account and a device&lt;/strong&gt;&lt;/p&gt;

&lt;h3 id=&quot;step-2-adding-firebase-to-your-project&quot;&gt;Step 2. Adding Firebase to your project&lt;/h3&gt;

&lt;blockquote&gt;
  &lt;p&gt;Prerequisite : You need to have Xcode 7.3 or higher for the FCM to work.&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;Head over to &lt;a href=&quot;https://console.firebase.google.com/&quot;&gt;Firebase console&lt;/a&gt; and click &lt;strong&gt;Create New Project&lt;/strong&gt;. Enter FCM_Tutorial as the name project and click create project. You will be redirected to a screen like this&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/41Rq8Ij.jpg&quot; alt=&quot;Firebase Console&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Click Add firebase to your iOS project and in the popup - &lt;strong&gt;Enter your project bundle id&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/gwUb9E1.jpg&quot; alt=&quot;Bundle id popup&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Press Add app and now you will get the &lt;strong&gt;GoogleService-Info.plist&lt;/strong&gt; downloaded automatically. Now keep pressing continue to finish the integration steps and get back to the project.&lt;/p&gt;

&lt;p&gt;Drag the plist you downloaded into your project root (where .xcodeProj file is). The plist file actually includes all the relevant settings for the firebase app including the firebase database url for your app.&lt;/p&gt;

&lt;h3 id=&quot;setup-pods&quot;&gt;Setup Pods&lt;/h3&gt;

&lt;p&gt;Open a terminal and execute &lt;strong&gt;pod init&lt;/strong&gt; in your project directory. Open the pod file in text editor or in Xcode and add these pods to the app target&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;pod &#39;Firebase/Core&#39;
pod &#39;Firebase/Messaging&#39;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Run &lt;strong&gt;pod install&lt;/strong&gt; in terminal and once completed open the &lt;strong&gt;.xcworkspace&lt;/strong&gt; file to open the project.&lt;/p&gt;

&lt;h4 id=&quot;intializing-firebase-in-our-app&quot;&gt;Intializing Firebase in our app&lt;/h4&gt;

&lt;p&gt;Open up Appdelegate.swift &lt;code class=&quot;highlighter-rouge&quot;&gt;didFinishLaunching&lt;/code&gt; method and in it add the line
&lt;code class=&quot;highlighter-rouge&quot;&gt;
        FIRApp.configure()
&lt;/code&gt;
Make sure to &lt;strong&gt;import Firebase&lt;/strong&gt; in each class you use Firebase.&lt;/p&gt;

&lt;h3 id=&quot;step-3-implementing-token-registeration-methods&quot;&gt;Step 3. Implementing token registeration methods&lt;/h3&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;    &lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIApplication&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
                     &lt;span class=&quot;n&quot;&gt;didRegisterForRemoteNotificationsWithDeviceToken&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;deviceToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;NSData&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;kt&quot;&gt;FIRInstanceID&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;instanceID&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;setAPNSToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;deviceToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;type&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;FIRInstanceIDAPNSTokenType&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Sandbox&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;kt&quot;&gt;FIRInstanceID&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;instanceID&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;setAPNSToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;deviceToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;type&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;FIRInstanceIDAPNSTokenType&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Prod&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;FIRInstanceID&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;instanceID&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;token&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;())&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;tokenChars&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UnsafePointer&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;CChar&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;gt;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;deviceToken&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;bytes&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;tokenString&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;&quot;&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;for&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;i&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;in&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;0&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;..&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;deviceToken&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;length&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;tokenString&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;format&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;%02.2hhx&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;arguments&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;tokenChars&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;i&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]])&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;tokenString: &lt;/span&gt;&lt;span class=&quot;se&quot;&gt;\(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;tokenString&lt;/span&gt;&lt;span class=&quot;se&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIApplication&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;didFailToRegisterForRemoteNotificationsWithError&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;error&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;NSError&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;error&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    &lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;&lt;strong&gt;didRegisterForRemoteNotificationsWithDeviceToken&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;In this method we save the device token to our FIRInstanceID so that our unique device token is made for Firebase.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;didFailToRegisterForRemoteNotificationsWithError&lt;/strong&gt;&lt;br /&gt;
&lt;strong&gt;keep a lookout&lt;/strong&gt; for this method, every time the app fails to register for remote notification - it will show the error details here.&lt;/p&gt;

&lt;p&gt;If you run the app in simulator now: You will face the Notification alert shown in step 1. Clicking Allow will give a error in the logs like&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;2016-09-01 19:19:04.639: &lt;span class=&quot;nt&quot;&gt;&amp;lt;FIRInstanceID&lt;/span&gt;&lt;span class=&quot;err&quot;&gt;/WARNING&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&amp;gt;&lt;/span&gt; Failed to fetch APNS token Error Domain=NSCocoaErrorDomain Code=3010 &quot;REMOTE_NOTIFICATION_SIMULATOR_NOT_SUPPORTED_NSERROR_DESCRIPTION&quot;
UserInfo={NSLocalizedDescription=REMOTE_NOTIFICATION_SIMULATOR_NOT_SUPPORTED_NSERROR_DESCRIPTION}&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Make sure to test on Device!.&lt;/p&gt;

&lt;hr /&gt;

&lt;h2 id=&quot;step-4-creating-app-certificate-and-provisioning&quot;&gt;Step 4. Creating App certificate and provisioning&lt;/h2&gt;

&lt;h3 id=&quot;what-they-are-and-why-are-they-needed&quot;&gt;What they are and why are they needed&lt;/h3&gt;

&lt;p&gt;You must already be knowing that to run app on devices - we need to have provisioning profile with the device udid added in it.
To send push notifications we also need to create separate push certificate and upload the &lt;strong&gt;.pem&lt;/strong&gt; or &lt;strong&gt;.p12&lt;/strong&gt; file on our server. Firebase require you to upload the .p12 file.&lt;/p&gt;

&lt;h3 id=&quot;simple-way---let-xcode-create-them&quot;&gt;Simple way - Let Xcode create them&lt;/h3&gt;

&lt;p&gt;Xcode 7 has the option to automatically create provisioning profile and certificates for you.&lt;/p&gt;

&lt;p&gt;Go to preferences in Xcode and Add your apple developer account if not already added.
&lt;img src=&quot;http://i.imgur.com/pMjxOuA.png&quot; alt=&quot;Xcode Account&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Next up is to set the team in Xcode. This will make Xcode use the appt. apple account to create the app id and provisioning for our app.&lt;br /&gt;
Here is a screenshot which shows where to set the team&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/TeUQS9d.jpg&quot; alt=&quot;Set Team&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Then head over to &lt;strong&gt;Capabilities&lt;/strong&gt; tab in your target and Enable Push Notifications
&lt;img src=&quot;http://i.imgur.com/KPRpA2d.jpg&quot; alt=&quot;Capabilities&quot; /&gt;
&lt;img src=&quot;http://i.imgur.com/NMIod1v.jpg&quot; alt=&quot;Enabling Push&quot; /&gt;
Xcode will now register your app id and enable the push certificates for you.&lt;/p&gt;

&lt;h3 id=&quot;longer-route---creating-certificate-and-provisioning-manually-for-push&quot;&gt;Longer route - Creating certificate and provisioning manually for push&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;If the easy way does not work and you don’t see the token still after running the app&lt;/strong&gt;, you would have to take the longer route of creating provisioning and certificates using Keychain Access and Apple Developer Portal.&lt;/p&gt;

&lt;p&gt;&lt;em&gt;I for personally blame Apple and Xcode for the provisioning messup :)&lt;/em&gt;&lt;/p&gt;

&lt;p&gt;Open up &lt;strong&gt;Keychain Access&lt;/strong&gt; app by finding it in the LaunchPad.&lt;/p&gt;

&lt;p&gt;Select Request a Certificate from a Certificate Authority in the App Menu
&lt;img src=&quot;http://i.imgur.com/IYkusVJ.jpg&quot; alt=&quot;Create a Certificate&quot; /&gt;&lt;/p&gt;

&lt;p&gt;In the New Window that opens, add the email and name and then select the option to save it to disk.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Note: Make sure to enter a name which has clear purpose, It is helpful in finding out keychain key in further steps&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/5YlDnda.jpg&quot; alt=&quot;Create Certificate Dialog&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Save the certificate to a place where you can locate it later on.&lt;/p&gt;

&lt;p&gt;Now proceed to &lt;a href=&quot;http://developer.apple.com&quot;&gt;Developer Center&lt;/a&gt; and login into your account.&lt;br /&gt;
In the App Id section - click on your app till you reach a similar screen with Edit button&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/2JH0fVt.jpg&quot; alt=&quot;Edit App id&quot; /&gt;
Click Edit and Scroll down to the Push certificate section
&lt;strong&gt;Create a Development SSL certificate as shown in the image&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/19pFIxj.jpg&quot; alt=&quot;Create Push Certificate for App Id&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Click Continue in the below screen
&lt;img src=&quot;http://i.imgur.com/8oypmGx.jpg&quot; alt=&quot;Create Certificate&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Select the certificate where you saved it
&lt;img src=&quot;http://i.imgur.com/WhGsPG4.jpg&quot; alt=&quot;Create Certificate&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Download the aps certificate created and double click it so that it is added to the Keychain.&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/KfoAnX2.jpg&quot; alt=&quot;Certificate in keychain&quot; /&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Right Click the Apple Push Services Key Row and Click Export&lt;/strong&gt;
Save the .p12 file now in a safe place and skip setting a password for the exported file for now.&lt;/p&gt;

&lt;h4 id=&quot;last-step-is-now-to-download-the-provisioning-profile&quot;&gt;Last Step is now to download the provisioning profile.&lt;/h4&gt;

&lt;p&gt;Everytime you update the certificates for push for your app id, the provisioning profiles are required to be regenerated so that they have the entitlements set.&lt;/p&gt;

&lt;p&gt;Go to the provisioning center and create a new/edit development provisioning profile &lt;strong&gt;(make sure it has your development device udid)&lt;/strong&gt; for your app and download it.&lt;br /&gt;
Open it up in your xcode and set it as the Development provisioning profile in &lt;strong&gt;Build Settings&lt;/strong&gt;&lt;/p&gt;

&lt;h3 id=&quot;step-5-testing-push-using-firebase-console&quot;&gt;Step 5. Testing push using Firebase Console&lt;/h3&gt;

&lt;p&gt;Time to test the push feature finally after all this setup :)&lt;/p&gt;

&lt;p&gt;You can now use Notification Console to start sending push notification to your app. Go to the notification console as shown in the following pics&lt;/p&gt;

&lt;blockquote&gt;
  &lt;p&gt;&lt;strong&gt;Note: For the notification to show make sure to kill the app after you get the token&lt;/strong&gt;&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/4Av4hyj.jpg&quot; alt=&quot;Notification Console&quot; /&gt;
&lt;img src=&quot;http://i.imgur.com/kc0UhSP.jpg&quot; alt=&quot;Compose Message&quot; /&gt;&lt;/p&gt;

&lt;p&gt;The token to use is the one printed using this line&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;         &lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;FIRInstanceID&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;instanceID&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;token&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;())&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;On the lock screen - you should see the app icon with the title &lt;code class=&quot;highlighter-rouge&quot;&gt;FIRST FCM MESSAGE&lt;/code&gt;&lt;/p&gt;

&lt;h2 id=&quot;other-things-to-keep-in-mind&quot;&gt;Other Things to Keep in Mind&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Few important things to keep in mind before finishing up&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;1) iOS App while in background/foreground receives the notification in Appdelegate &lt;strong&gt;didReceiveRemoteNotification&lt;/strong&gt; method. It is your resposibility to show the alert as well as any other action in this case by parsing the payload&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;  &lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;application&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIApplication&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;didReceiveRemoteNotification&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;userInfo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;NSObject&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;AnyObject&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;],&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;fetchCompletionHandler&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;completionHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;UIBackgroundFetchResult&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&amp;gt;&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Void&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;userInfo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;2) &lt;strong&gt;App Store/Adhoc build will use the Distribution SSL Certificate for the Push certificate.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Make sure to repeat the steps above to make the distribution push certificate when submitting app to the store.&lt;/p&gt;

&lt;h2 id=&quot;conclusion&quot;&gt;Conclusion&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Thank you&lt;/strong&gt; for reading this far. For any questions you are welcome to ask in our chat room.&lt;/p&gt;

&lt;h2 id=&quot;next-steps&quot;&gt;Next Steps&lt;/h2&gt;

&lt;p&gt;Please take a look at our other &lt;a href=&quot;../../tutorials&quot;&gt;tutorials&lt;/a&gt; :)&lt;/p&gt;
</description>
        <pubDate>Sat, 02 Jul 2016 00:00:00 +0530</pubDate>
        <link>http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/07/Push-Notification-in-iOS-using-FCM-(Swift)</link>
        <guid isPermaLink="true">http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/07/Push-Notification-in-iOS-using-FCM-(Swift)</guid>
        
        <category>intro</category>
        
        <category>beginner</category>
        
        <category>swift</category>
        
        <category>tutorial</category>
        
        
        <category>lessons</category>
        
      </item>
    
      <item>
        <title>Implementing Fcm ( Firebase Cloud  Messaging ) In Android App</title>
        <description>&lt;blockquote&gt;
  &lt;p&gt;The final project is available for download from the &lt;a href=&quot;https://github.com/Shubhank101/iOSAndroidChaosOverFlow-Projects&quot;&gt;Github repository&lt;/a&gt;&lt;/p&gt;
&lt;/blockquote&gt;

&lt;h2 id=&quot;what-is-fcm&quot;&gt;What is FCM?&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;FCM (Firebase Cloud Messaging)&lt;/strong&gt; replaces Google Cloud Messaging (GCM) as the API to send/receive push notifications from.&lt;br /&gt;
Most of the popular apps in the market uses push notifications to engage the user and i am sure you are interested to implement them in your app too so follow along.&lt;/p&gt;

&lt;h3 id=&quot;how-does-fcm-work&quot;&gt;How does FCM work&lt;/h3&gt;

&lt;p&gt;&lt;img src=&quot;https://firebase.google.com/docs/cloud-messaging/images/messaging-overview.png&quot; alt=&quot;FCM Diagram&quot; /&gt;&lt;/p&gt;

&lt;p&gt;As shown in the figure, the FCM is the middle ware between your device and the server.&lt;br /&gt;
You send the message you want to send to the devices to the Firebase server and it redirects it to the appropriate device. It handles all the middle ware part like scheduling notification time, failure and success rate, unique device tokens etc.&lt;/p&gt;

&lt;p&gt;We can use a http/xmpp server to send the message to the FCM server but in our tutorial we use the handy tool provided by the FCM guys - &lt;strong&gt;Notification console&lt;/strong&gt;.&lt;/p&gt;

&lt;h3 id=&quot;step-1-setting-up-the-android-project&quot;&gt;Step 1. Setting up the Android project&lt;/h3&gt;

&lt;blockquote&gt;
  &lt;p&gt;Prerequisite : You need to have Studio with version &lt;strong&gt;1.5&lt;/strong&gt; or higher for the services to work.&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;Create a new Android Studio Project and name it FCM_Tutorial.
Now note down the &lt;strong&gt;package name&lt;/strong&gt;, we will need it to make the &lt;code class=&quot;highlighter-rouge&quot;&gt;google-services.json&lt;/code&gt; file.&lt;/p&gt;

&lt;p&gt;Head over to &lt;a href=&quot;https://console.firebase.google.com/&quot;&gt;Firebase console&lt;/a&gt; and click &lt;strong&gt;Create New Project&lt;/strong&gt;. Enter FCM_Tutorial as the name project and click create project. You will be redirected to a screen like this&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/41Rq8Ij.jpg&quot; alt=&quot;Firebase Console&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Click Add firebase to your Android project and in the popup - &lt;strong&gt;Enter your package name&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/s7EuCON.jpg&quot; alt=&quot;Package popup&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Press Add app and now you will get the &lt;strong&gt;google-services.json&lt;/strong&gt; downloaded automatically. Now keep pressing continue to finish the integration steps and get back to the project.&lt;/p&gt;

&lt;p&gt;Drag the json you downloaded into your project root (where .build gradle file is of the app module). The json file actually includes all the relevant settings for the firebase app including the firebase database url for your app.&lt;/p&gt;

&lt;h3 id=&quot;setup-gradle&quot;&gt;Setup Gradle&lt;/h3&gt;

&lt;p&gt;Open your project build.gradle file and add the following dependencies&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt; dependencies {
      classpath &#39;com.android.tools.build:gradle:2.1.0&#39;
      classpath &#39;com.google.gms:google-services:3.0.0&#39;
  }&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Now open your app module build.grade and add these dependencies&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;    compile &#39;com.google.firebase:firebase-core:9.0.1&#39;
    compile &#39;com.google.firebase:firebase-messaging:9.0.1&#39;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;At the end of the file we need to apply our google play servcies plugin :&lt;/p&gt;

&lt;p&gt;&lt;code class=&quot;highlighter-rouge&quot;&gt;apply plugin: &#39;com.google.gms.google-services&#39;&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;Sync your gradle and you will have the firebase setup in your project.&lt;/p&gt;

&lt;h3 id=&quot;step-2-creating-our-tokenservice&quot;&gt;Step 2. Creating our TokenService&lt;/h3&gt;

&lt;p&gt;Each device need to be uniquely identified so that we can check success/failure and target individual user. Firebase provides &lt;strong&gt;FirebaseInstanceId&lt;/strong&gt; class which takes care of creating unique device token for the current device.&lt;br /&gt;
The token is refreshed randomly based on duration or other things so to avoid checking each time for new token, We have to use a Service class that extends &lt;strong&gt;FirebaseInstanceIdService&lt;/strong&gt;.&lt;br /&gt;
In it, the &lt;strong&gt;onTokenRefresh&lt;/strong&gt; is called each time a new token is generated.&lt;/p&gt;

&lt;p&gt;So it’s time to create a new class in our project. Name it &lt;strong&gt;TokenService.java&lt;/strong&gt; and have it extend &lt;strong&gt;FirebaseInstanceIdService&lt;/strong&gt;. Here is our implementation&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;    
&lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;TokenService&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;extends&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;FirebaseInstanceIdService&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

    &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onTokenRefresh&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;c1&quot;&gt;// Get updated InstanceID token.&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;refreshedToken&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;FirebaseInstanceId&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getInstance&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getToken&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;Log&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;w&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;notification&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;refreshedToken&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;sendRegistrationToServer&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;refreshedToken&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;sendRegistrationToServer&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;token&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;We get the token from the FirebaseInstanceId instance and just log it currently to the logcat so that we can use it later. You can send it to server in a production app to store it in your db.&lt;/p&gt;

&lt;h3 id=&quot;step-3-registering-our-service-in-manifest&quot;&gt;Step 3. Registering our service in manifest&lt;/h3&gt;

&lt;p&gt;For our TokenService to actually work we need to make sure it is added to our &lt;strong&gt;AndroidManifest.xml&lt;/strong&gt; file.
Open up the manifest and inside our &lt;strong&gt;application&lt;/strong&gt; tag add the service lines&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;  &lt;span class=&quot;nt&quot;&gt;&amp;lt;service&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:name=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;.TokenService&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&amp;gt;&lt;/span&gt;
        &lt;span class=&quot;nt&quot;&gt;&amp;lt;intent-filter&amp;gt;&lt;/span&gt;
            &lt;span class=&quot;nt&quot;&gt;&amp;lt;action&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;android:name=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;com.google.firebase.INSTANCE_ID_EVENT&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;
        &lt;span class=&quot;nt&quot;&gt;&amp;lt;/intent-filter&amp;gt;&lt;/span&gt;
   &lt;span class=&quot;nt&quot;&gt;&amp;lt;/service&amp;gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Run the app and you should see the token in Logcat.&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/o2oICrI.jpg&quot; alt=&quot;Token in Logcat&quot; /&gt;&lt;/p&gt;

&lt;h3 id=&quot;step-4-testing-a-push-notification-through-the-notification-console&quot;&gt;Step 4. Testing A Push notification through the Notification Console&lt;/h3&gt;

&lt;p&gt;This was really easy right. You can now use Notification Console to start sending push notification to your app. Go to the notification console as shown in the following pics&lt;/p&gt;

&lt;blockquote&gt;
  &lt;p&gt;&lt;strong&gt;Note: For the notification to show make sure the app is in background and not in foreground&lt;/strong&gt;&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/4Av4hyj.jpg&quot; alt=&quot;Notification Console&quot; /&gt;
&lt;img src=&quot;http://i.imgur.com/kc0UhSP.jpg&quot; alt=&quot;Compose Message&quot; /&gt;&lt;/p&gt;

&lt;p&gt;In the second screenshot, you can set the Title and also send messages based on filter like all devices/groups/particular device, adjust time for your notification. We will use the &lt;strong&gt;Single device&lt;/strong&gt; and use the token we got in #step 3 of our tutorial.&lt;/p&gt;

&lt;p&gt;After filling the title and token, scroll down and click Send Message. You will see the notification show up in your device notification panel.&lt;/p&gt;

&lt;h3 id=&quot;step-5-creating-our-fcmmessagereceiverservice&quot;&gt;Step 5. Creating our FCMMessageReceiverService&lt;/h3&gt;

&lt;p&gt;Well our app is able to receive notifications and show in our app but in actual we don’t have any code in our app that actually does the part of displaying the notification. This can be tested by doing &lt;strong&gt;step 4&lt;/strong&gt; with app in foreground, you won’t see the notification with app in foreground.&lt;/p&gt;

&lt;p&gt;This is a feature of Firebase; it shows the notification automatically if the app is in background. However if the app is in foreground, we have to extend &lt;strong&gt;FirebaseMessagingService&lt;/strong&gt;.&lt;/p&gt;

&lt;p&gt;This class has a method &lt;strong&gt;onMessageReceived&lt;/strong&gt; which is called when a FCM is received in foreground. Create a new class in your project and name it &lt;strong&gt;FCMMessageReceiverService&lt;/strong&gt;.&lt;/p&gt;

&lt;p&gt;Here is our implementation :&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;&lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;FCMMessageReceiverService&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;extends&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;FirebaseMessagingService&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;


    &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onMessageReceived&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RemoteMessage&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;remoteMessage&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;Log&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;w&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;fcm&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;received notification&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;sendNotification&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;remoteMessage&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getNotification&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getTitle&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;sendNotification&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;messageBody&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;intent&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;MainActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;class&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;addFlags&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;FLAG_ACTIVITY_CLEAR_TOP&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;PendingIntent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;pendingIntent&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;PendingIntent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;0&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;PendingIntent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;FLAG_ONE_SHOT&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;Uri&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;defaultSoundUri&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;RingtoneManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getDefaultUri&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RingtoneManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;TYPE_NOTIFICATION&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;NotificationCompat&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;Builder&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;notificationBuilder&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;NotificationCompat&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;Builder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt;
                &lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setSmallIcon&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;mipmap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;ic_launcher&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt;
                &lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setContentTitle&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;messageBody&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt;
                &lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setAutoCancel&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kc&quot;&gt;false&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt;
                &lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setSound&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;defaultSoundUri&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;NotificationManager&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;notificationManager&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt;
                &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;NotificationManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;getSystemService&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Context&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;NOTIFICATION_SERVICE&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;notificationManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;notify&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;mi&quot;&gt;1&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;notificationBuilder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;build&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

&lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;We override onMessageReceived and call the &lt;code class=&quot;highlighter-rouge&quot;&gt;sendNotification&lt;/code&gt; method with the FCM title. The notification method simply creates a Notification and show it.&lt;/p&gt;

&lt;h3 id=&quot;step-6-registering-our-message-service-in-manifest&quot;&gt;Step 6. Registering our message service in manifest&lt;/h3&gt;

&lt;p&gt;Just like TokenService our FCMMessageReceiverService needs to be registered in manifest too so that it is visible and can be called by Firebase. Update your manifest application tag with&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;   &lt;span class=&quot;nt&quot;&gt;&amp;lt;service&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:name=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;.FCMMessageReceiverService&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&amp;gt;&lt;/span&gt;
        &lt;span class=&quot;nt&quot;&gt;&amp;lt;intent-filter&amp;gt;&lt;/span&gt;
              &lt;span class=&quot;nt&quot;&gt;&amp;lt;action&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;android:name=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;com.google.firebase.MESSAGING_EVENT&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;
        &lt;span class=&quot;nt&quot;&gt;&amp;lt;/intent-filter&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;/service&amp;gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;h4 id=&quot;testing-our-push-notification-once-again&quot;&gt;Testing our push notification once again&lt;/h4&gt;

&lt;p&gt;Go Ahead and do the &lt;strong&gt;Step 4&lt;/strong&gt; again with app in foreground. You will see the logcat show the message &lt;em&gt;received notification&lt;/em&gt; as well as the notification appear in the notification panel.&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/XFt3z28.jpg&quot; alt=&quot;Notification Message in Device&quot; /&gt;&lt;/p&gt;

&lt;h2 id=&quot;conclusion&quot;&gt;Conclusion&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Thank you&lt;/strong&gt; for reading this far. For any questions you are welcome to ask in our chat room.&lt;/p&gt;

&lt;h2 id=&quot;next-steps&quot;&gt;Next Steps&lt;/h2&gt;

&lt;p&gt;Please take a look at our other &lt;a href=&quot;../../tutorials&quot;&gt;tutorials&lt;/a&gt; :)&lt;/p&gt;
</description>
        <pubDate>Thu, 02 Jun 2016 00:00:00 +0530</pubDate>
        <link>http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/06/Implementing-FCM-(-Firebase-Cloud-Messaging-)-in-Android-App</link>
        <guid isPermaLink="true">http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/06/Implementing-FCM-(-Firebase-Cloud-Messaging-)-in-Android-App</guid>
        
        <category>intro</category>
        
        <category>beginner</category>
        
        <category>swift</category>
        
        <category>tutorial</category>
        
        
        <category>lessons</category>
        
      </item>
    
      <item>
        <title>Todo App With Firebase Part 1 (android)</title>
        <description>&lt;blockquote&gt;
  &lt;p&gt;This tutorial assumes you are familiar with basics of Android development including Android Studio, java and gradle.&lt;/p&gt;
&lt;/blockquote&gt;

&lt;h1 id=&quot;what-is-firebase&quot;&gt;What is Firebase?&lt;/h1&gt;

&lt;p&gt;&lt;img src=&quot;https://1.bp.blogspot.com/-YIfQT6q8ZM4/Vzyq5z1B8HI/AAAAAAAAAAc/UmWSSMLKtKgtH7CACElUp12zXkrPK5UoACLcB/s1600/image00.png&quot; alt=&quot;Firebase logo&quot; /&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Firebase&lt;/strong&gt; is a multi purpose sdk which can be used to integrate push notifications in your app, app analytics and a whole lot of other features which you can review on its site.&lt;/p&gt;

&lt;p&gt;We are going to use &lt;strong&gt;Firebase Realtime Database&lt;/strong&gt; here to develop a simple To-do app.&lt;/p&gt;

&lt;h2 id=&quot;step-1-setting-up-android-project&quot;&gt;Step 1. Setting up Android Project&lt;/h2&gt;

&lt;blockquote&gt;
  &lt;p&gt;Prerequisite : You need to have Studio with version &lt;strong&gt;1.5&lt;/strong&gt; or higher for the services to work.&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;Create a new Android Studio Project and name it TodoApp.
Now note down the &lt;strong&gt;package name&lt;/strong&gt;, we will need it to make the &lt;code class=&quot;highlighter-rouge&quot;&gt;google-services.json&lt;/code&gt; file.&lt;/p&gt;

&lt;p&gt;Head over to &lt;a href=&quot;https://console.firebase.google.com/&quot;&gt;Firebase console&lt;/a&gt; and click &lt;strong&gt;Create New Project&lt;/strong&gt;. Enter TodoApp as the name project and click create project. You will be redirected to a screen like this&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/41Rq8Ij.jpg&quot; alt=&quot;Firebase Console&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Click Add firebase to your Android project and in the popup - &lt;strong&gt;Enter your package name&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/s7EuCON.jpg&quot; alt=&quot;Package popup&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Press Add app and now you will get the &lt;strong&gt;google-services.json&lt;/strong&gt; downloaded automatically. Now keep pressing continue to finish the integration steps and get back to the project.&lt;/p&gt;

&lt;p&gt;Drag the json you downloaded into your project root (where .build gradle file is of the app module). The json file actually includes all the relevant settings for the firebase app including the firebase database url for your app.&lt;/p&gt;

&lt;h3 id=&quot;setup-gradle&quot;&gt;Setup Gradle&lt;/h3&gt;

&lt;p&gt;Open your project build.gradle file and add the following dependencies&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt; dependencies {
      classpath &#39;com.android.tools.build:gradle:2.1.0&#39;
      classpath &#39;com.google.gms:google-services:3.0.0&#39;
  }&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Now open your app module build.grade and add these dependencies&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;    compile &#39;com.google.firebase:firebase-core:9.0.1&#39;
    compile &#39;com.google.firebase:firebase-database:9.0.1&#39;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;At the end of the file we need to apply our google play servcies plugin :&lt;/p&gt;

&lt;p&gt;&lt;code class=&quot;highlighter-rouge&quot;&gt;apply plugin: &#39;com.google.gms.google-services&#39;&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;Sync your gradle and you will have the firebase setup in your project.&lt;/p&gt;

&lt;h2 id=&quot;step-2-making-the-app-ui&quot;&gt;Step 2. Making the App UI&lt;/h2&gt;

&lt;p&gt;We need to setup a basic UI to actually see our firebase code in work. I am going to explain in short here with enough details to actually carry out yourself.&lt;/p&gt;

&lt;p&gt;We will be having two activity in this project. MainActivity and TodoActivity.&lt;br /&gt;
 The UI you need to make is shown in the screenshot&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/iyLXjKU.jpg&quot; alt=&quot;App&#39;s UI&quot; /&gt;&lt;/p&gt;

&lt;p&gt;The first activity has a recycleview and a Floating action button (FAB) in it. We will fill the recycle view with our firebase todo list and the action button takes to the TodoActivity using intent.&lt;/p&gt;

&lt;p&gt;The TodoActivity has three Textviews and two EditText + a date picker in it. Pretty simple stuff.
 Make a new &lt;strong&gt;TodoActivity.java&lt;/strong&gt; class in your project and make the appropriate layout for it. Make sure to give ids to EditText, DatePicker to access them in activity.
 Also add a FAB in this class on which we will actually save our Todo to the firebase db. Give appt id to it&lt;/p&gt;

&lt;h2 id=&quot;step-3-making-the-model&quot;&gt;Step 3. Making the Model&lt;/h2&gt;

&lt;p&gt;Our Todo won’t be a ArrayList or Hashmap lying around here and there in a project. We will make a proper model class for it.
Make a new &lt;strong&gt;Todo.java&lt;/strong&gt; in your project and replace its content with the following&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;&lt;span class=&quot;n&quot;&gt;ublic&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;Todo&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;implements&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Serializable&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;name&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;message&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;getDate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;setDate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;date&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;getName&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;name&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;setName&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;name&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;name&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;name&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;getMessage&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;message&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;setMessage&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;message&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;message&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;message&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;


    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;HashMap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;toFirebaseObject&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;HashMap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt;  &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;HashMap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;gt;();&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;put&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;name&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;name&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;put&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;message&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;message&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;put&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;date&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

&lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;h2 id=&quot;step-4-back-to-understanding-how-firebase-works&quot;&gt;Step 4. Back to understanding how Firebase works&lt;/h2&gt;

&lt;p&gt;The database your app has on the firebase cloud is available on a public url like https://appname-randomIdentifer.firebaseio.com/.
Since it is public anyone can read/write to it if the url is known. To solve this the &lt;strong&gt;database rules&lt;/strong&gt; section is provided where you can change the access/write rights.&lt;/p&gt;

&lt;p&gt;By default firebase database require user to be authenticated before writing to the database.&lt;/p&gt;

&lt;h3 id=&quot;changing-database-rules&quot;&gt;Changing Database Rules&lt;/h3&gt;

&lt;p&gt;In this begginer tutorial we are going to remove the authentication required to read/write from our database. Note: &lt;strong&gt;You should not have this for a production app&lt;/strong&gt;.&lt;/p&gt;

&lt;p&gt;Go to the database section in the firebase console and change to the rules tab. Update the rules with the below and click publish.&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-json&quot; data-lang=&quot;json&quot;&gt;&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
  &lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&quot;rules&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;w&quot;&gt; &lt;/span&gt;&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
    &lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&quot;.read&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;w&quot;&gt; &lt;/span&gt;&lt;span class=&quot;kc&quot;&gt;true&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
    &lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&quot;.write&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;w&quot;&gt; &lt;/span&gt;&lt;span class=&quot;kc&quot;&gt;true&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
  &lt;/span&gt;&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/W4a6Xjm.jpg&quot; alt=&quot;Rules&quot; /&gt;&lt;/p&gt;

&lt;h2 id=&quot;database-structure&quot;&gt;Database Structure&lt;/h2&gt;

&lt;p&gt;Firebase database is actually a NoSQL
one, you won’t see any tables and where clauses in it and it is therefore &lt;strong&gt;a big change&lt;/strong&gt; for many developers out there.&lt;/p&gt;

&lt;p&gt;Our app has a simple Todo structure which arranged in a typical SQL database would look like.&lt;/p&gt;

&lt;table&gt;
  &lt;tbody&gt;
    &lt;tr&gt;
      &lt;td&gt;Name&lt;/td&gt;
      &lt;td&gt;Message&lt;/td&gt;
      &lt;td&gt;Date&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
      &lt;td&gt;First&lt;/td&gt;
      &lt;td&gt;Message&lt;/td&gt;
      &lt;td&gt;10/10/16 10:10&lt;/td&gt;
    &lt;/tr&gt;
  &lt;/tbody&gt;
&lt;/table&gt;

&lt;p&gt;But in &lt;strong&gt;Firebase JSON syntax&lt;/strong&gt;, we would have to do something like this
&lt;img src=&quot;http://i.imgur.com/rGOklwM.jpg&quot; alt=&quot;Db structure&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Each todo is uniquely identified by its key which firebase creates and our todoList is actually and array for the key &lt;strong&gt;todo&lt;/strong&gt; in our db.&lt;/p&gt;

&lt;hr /&gt;

&lt;h2 id=&quot;coding-actual-firebase-logic&quot;&gt;Coding Actual Firebase Logic&lt;/h2&gt;

&lt;h3 id=&quot;step-5-saving-a-new-todo-in-the-firebase-db&quot;&gt;Step 5. Saving a new Todo in the Firebase Db&lt;/h3&gt;

&lt;p&gt;Now switch to TodoActivity.java and get the reference of the FAB button and set a clicklistener to it. In it we call our &lt;strong&gt;saveTodo&lt;/strong&gt; method.&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;        &lt;span class=&quot;n&quot;&gt;FloatingActionButton&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;fab&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;FloatingActionButton&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;fab&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;fab&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setOnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;View&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;OnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onClick&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;View&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;view&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;saveTodo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;});&lt;/span&gt;
        
        &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;saveTodo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;c1&quot;&gt;// first section&lt;/span&gt;
            &lt;span class=&quot;c1&quot;&gt;// get the data to save in our firebase db&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;EditText&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;nameEdtText&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;EditText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;nameEditText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;EditText&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;messageEditText&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;EditText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;messageEditText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;DatePicker&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DatePicker&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;datePicker&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;Date&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setMonth&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getMonth&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setYear&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getYear&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setDate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getDayOfMonth&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
    
            &lt;span class=&quot;n&quot;&gt;SimpleDateFormat&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;format&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;SimpleDateFormat&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;dd/MM/yyyy HH:mm&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
    
            &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dateString&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;format&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;format&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;c1&quot;&gt;//make the modal object and convert it into hasmap&lt;/span&gt;
    
          
            &lt;span class=&quot;c1&quot;&gt;//second section&lt;/span&gt;
            &lt;span class=&quot;c1&quot;&gt;//save it to the firebase db&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;FirebaseDatabase&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;database&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;FirebaseDatabase&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getInstance&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;key&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;database&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getReference&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;todoList&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;).&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;push&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getKey&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
    
            &lt;span class=&quot;n&quot;&gt;Todo&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setName&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;nameEdtText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;toString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setMessage&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;messageEditText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;toString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setDate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;dateString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
    
            &lt;span class=&quot;n&quot;&gt;Map&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Object&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;childUpdates&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;HashMap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&amp;gt;();&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;childUpdates&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;put&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;key&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;toFirebaseObject&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;database&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getReference&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;todoList&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;).&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;updateChildren&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;childUpdates&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DatabaseReference&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;CompletionListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
                &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onComplete&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DatabaseError&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;databaseError&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DatabaseReference&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;databaseReference&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                    &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;databaseError&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;==&lt;/span&gt; &lt;span class=&quot;kc&quot;&gt;null&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                        &lt;span class=&quot;n&quot;&gt;finish&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
                    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
                &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;});&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Our code first section does the typical model object filling by getting the values from our view object. You can go ahead and add validation logic here if you want. The real firebase work is done in the second section.&lt;/p&gt;

&lt;p&gt;In Second section , we get the database reference first and then try to get the “todoList” child in our db by calling &lt;code class=&quot;highlighter-rouge&quot;&gt;database.getReference(&quot;todoList&quot;)&lt;/code&gt;.&lt;br /&gt;
Since writing to our todoList endpoint each time will just overwrite previous values, we need to get a unique key for our new todo so that we can push it for that particular key only. We call the &lt;code class=&quot;highlighter-rouge&quot;&gt;push().getKey()&lt;/code&gt; on our todoList endpoint.&lt;/p&gt;

&lt;p&gt;Now we need to convert our model into a Hashmap since Firebase cannot save custom classes. &lt;strong&gt;String/ArrayList/Integer and Hashmap are the only supported types&lt;/strong&gt;.
On the next line we define the childUpdate model that is for /todoList/key end point =&amp;gt; set our dictionary object.
Calling the updateChildren performs the actual operation and we can pass a completion listener to detect any error that might have occured in the request.&lt;/p&gt;

&lt;p&gt;Try running the app now and click the FAB button in MainActivity -&amp;gt; goes to TodoActivity and in it save a new Todo. Firebase console should start showing up data that we save in the app.&lt;/p&gt;

&lt;h3 id=&quot;step-6-retreiving-all-our-todo-from-the-db&quot;&gt;Step 6. Retreiving all our Todo from the DB&lt;/h3&gt;

&lt;p&gt;Firebase allow you to constantly listen to a end point for any value but in our app we only want to load data once.
MainActivity code is given below :&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;   &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;MainActivity&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;extends&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;AppCompatActivity&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

    &lt;span class=&quot;n&quot;&gt;RecycleAdapter&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;adapter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;n&quot;&gt;ArrayList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;

    &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;protected&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onCreate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Bundle&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;savedInstanceState&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;kd&quot;&gt;super&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;onCreate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;savedInstanceState&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;setContentView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;layout&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;activity_main&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;Toolbar&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;toolbar&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Toolbar&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;toolbar&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;setSupportActionBar&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;toolbar&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;FloatingActionButton&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;fab&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;FloatingActionButton&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;fab&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;fab&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setOnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;View&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;OnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onClick&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;View&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;view&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;newIntent&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;MainActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TodoActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;class&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;MainActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;startActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;newIntent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;});&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ArrayList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&amp;gt;();&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;RecyclerView&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;recyclerView&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RecyclerView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;myrecycleView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;LinearLayoutManager&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;llm&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;LinearLayoutManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;recyclerView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setLayoutManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;llm&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;adapter&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;RecycleAdapter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;recyclerView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setAdapter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;adapter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;adapter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;notifyDataSetChanged&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;


    &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;protected&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onResume&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;kd&quot;&gt;super&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;onResume&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;FirebaseDatabase&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;database&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;FirebaseDatabase&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getInstance&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;database&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getReference&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;todoList&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;).&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;addListenerForSingleValueEvent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;
                &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ValueEventListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                    &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
                    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onDataChange&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DataSnapshot&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dataSnapshot&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                        &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;clear&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;

                        &lt;span class=&quot;n&quot;&gt;Log&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;w&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;TodoApp&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;getUser:onCancelled &quot;&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dataSnapshot&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;toString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
                        &lt;span class=&quot;n&quot;&gt;Log&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;w&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;TodoApp&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;count = &quot;&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;valueOf&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;dataSnapshot&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getChildrenCount&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;())&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot; values &quot;&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dataSnapshot&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getKey&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
                        &lt;span class=&quot;k&quot;&gt;for&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DataSnapshot&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;data&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dataSnapshot&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getChildren&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;())&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                            &lt;span class=&quot;n&quot;&gt;Todo&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;data&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getValue&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;class&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
                            &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;add&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
                        &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

                        &lt;span class=&quot;n&quot;&gt;adapter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;notifyDataSetChanged&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
                    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

                    &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
                    &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onCancelled&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DatabaseError&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;databaseError&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                        &lt;span class=&quot;n&quot;&gt;Log&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;w&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;TodoApp&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;getUser:onCancelled&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;databaseError&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;toException&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
                    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
                &lt;span class=&quot;o&quot;&gt;});&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;RecycleAdapter&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;extends&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;RecyclerView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;Adapter&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;


        &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
        &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;getItemCount&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;size&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
        &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;RecyclerView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;ViewHolder&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onCreateViewHolder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ViewGroup&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;parent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;viewType&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;View&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;v&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;LayoutInflater&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;from&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;parent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getContext&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()).&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;inflate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;layout&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;todo_item&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;parent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kc&quot;&gt;false&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;SimpleItemViewHolder&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;pvh&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;SimpleItemViewHolder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;v&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;pvh&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
        &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onBindViewHolder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RecyclerView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;ViewHolder&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;holder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;position&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;SimpleItemViewHolder&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;viewHolder&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;SimpleItemViewHolder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;holder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;viewHolder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;position&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;position&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;Todo&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;position&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;SimpleItemViewHolder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;holder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;).&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;title&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getName&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;final&lt;/span&gt;  &lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;SimpleItemViewHolder&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;extends&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;RecyclerView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;ViewHolder&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;implements&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;View&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;OnClickListener&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;TextView&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;title&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;position&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;SimpleItemViewHolder&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;View&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;itemView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;kd&quot;&gt;super&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;itemView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;itemView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setOnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;title&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TextView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;itemView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;myTextView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

            &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onClick&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;View&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;view&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

&lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;First we declare a ArrayList which will hold all our Todo model objects. Next we call the loadData method in our &lt;code class=&quot;highlighter-rouge&quot;&gt;onResume&lt;/code&gt; method so that our data is refreshed everytime MainActivity is launched as well as when we come back to the view after saving a new Todo.
In &lt;strong&gt;loadData&lt;/strong&gt; we get the reference to our &lt;strong&gt;todoList&lt;/strong&gt; endpoint and call the &lt;strong&gt;addListenerForSingleValueEvent&lt;/strong&gt; method since that observes the value event only one and is not kept in memory all the time listening for any real time changes in our end point. In the closure &lt;strong&gt;dataSnapshot.value&lt;/strong&gt; contains the value of that endpoint.&lt;/p&gt;

&lt;p&gt;If you observe the db in the console; each todo is uniquely identified by a key therefore in our case the snapshot.value actually contains children with as much number of Todo. If our model is a &lt;strong&gt;Java Pojo&lt;/strong&gt; we can cast it into a &lt;code class=&quot;highlighter-rouge&quot;&gt;Todo&lt;/code&gt; object using  &lt;strong&gt;data.getValue(Todo.class);&lt;/strong&gt;. snapshot will contain all our todo so we enumberate its children which containe name,message and date of our Todo, we fill up our model with that and add it to the array. In the end we call our recycleview adapter &lt;strong&gt;notifyDataSetChanged&lt;/strong&gt; to show the list of Todo in our UI.&lt;/p&gt;

&lt;h3 id=&quot;step-7-viewing-existing-todo&quot;&gt;Step 7. Viewing existing Todo&lt;/h3&gt;

&lt;p&gt;We do have our todo being retrieved and the name being shown in recycleview but clicking one should go to the &lt;strong&gt;TodoActivity&lt;/strong&gt; and show all details right ? So in the &lt;em&gt;onClick&lt;/em&gt; method in your ViewHolder class&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt; &lt;span class=&quot;kd&quot;&gt;@Override&lt;/span&gt;
&lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;onClick&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;View&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;view&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;kt&quot;&gt;Intent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;newIntent&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Intent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;MainActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;TodoActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
    &lt;span class=&quot;n&quot;&gt;newIntent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;putExtra&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;todo&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;position&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;));&lt;/span&gt;
    &lt;span class=&quot;kt&quot;&gt;MainActivity&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;startActivity&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;newIntent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Real simple code right there. Now you need to show those details in the outlets in your TodoActivity class. Update its &lt;strong&gt;onCreate&lt;/strong&gt; with the following code&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt; &lt;span class=&quot;c1&quot;&gt;// previous onCreate code&lt;/span&gt;
 &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getIntent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getExtras&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;!=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;null&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
      &lt;span class=&quot;kt&quot;&gt;Bundle&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;extras&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;getIntent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getExtras&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
      &lt;span class=&quot;kt&quot;&gt;Todo&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;extras&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;todo&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
      &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;!=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;null&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
          &lt;span class=&quot;kt&quot;&gt;EditText&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;nameEdtText&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;EditText&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;nameEditText&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
          &lt;span class=&quot;kt&quot;&gt;EditText&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;messageEditText&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;EditText&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;messageEditText&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
          &lt;span class=&quot;kt&quot;&gt;DatePicker&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;DatePicker&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;

          &lt;span class=&quot;n&quot;&gt;nameEdtText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;setText&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getName&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;());&lt;/span&gt;
          &lt;span class=&quot;n&quot;&gt;messageEditText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;setText&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getMessage&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;());&lt;/span&gt;

          &lt;span class=&quot;kt&quot;&gt;SimpleDateFormat&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;format&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;SimpleDateFormat&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;dd/MM/yyyy HH:mm&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
          &lt;span class=&quot;k&quot;&gt;try&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
              &lt;span class=&quot;kt&quot;&gt;Date&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;format&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;parse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getDate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;());&lt;/span&gt;
              &lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;updateDate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getYear&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(),&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getMonth&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(),&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;getDate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;());&lt;/span&gt;
          &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;catch&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;ParseException&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;e&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
              &lt;span class=&quot;n&quot;&gt;e&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;printStackTrace&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
          &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
 &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
 &lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;That’s it to have our todo app functioning on our firebase database :).&lt;/p&gt;

&lt;h2 id=&quot;conclusion&quot;&gt;Conclusion&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Thank you&lt;/strong&gt; for reading this far. For any questions you are welcome to ask in our chat room.&lt;/p&gt;

&lt;h2 id=&quot;next-steps&quot;&gt;Next Steps&lt;/h2&gt;

&lt;p&gt;Please take a look at our other &lt;a href=&quot;../../tutorials&quot;&gt;tutorials&lt;/a&gt; :)&lt;/p&gt;
</description>
        <pubDate>Wed, 01 Jun 2016 00:00:00 +0530</pubDate>
        <link>http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/06/todo-app-with-firebase-part-1-(Android)</link>
        <guid isPermaLink="true">http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/06/todo-app-with-firebase-part-1-(Android)</guid>
        
        <category>firebase</category>
        
        <category>android</category>
        
        <category>java</category>
        
        <category>tutorial</category>
        
        <category>todo app</category>
        
        
        <category>lessons</category>
        
      </item>
    
      <item>
        <title>Todo App With Firebase Part 1 (xcode)</title>
        <description>&lt;blockquote&gt;
  &lt;p&gt;This tutorial assumes you are familiar with basics of iOS development including Xcode, swift and cocoapods.&lt;/p&gt;
&lt;/blockquote&gt;

&lt;h1 id=&quot;what-is-firebase&quot;&gt;What is Firebase?&lt;/h1&gt;

&lt;p&gt;&lt;img src=&quot;https://1.bp.blogspot.com/-YIfQT6q8ZM4/Vzyq5z1B8HI/AAAAAAAAAAc/UmWSSMLKtKgtH7CACElUp12zXkrPK5UoACLcB/s1600/image00.png&quot; alt=&quot;Firebase logo&quot; /&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Firebase&lt;/strong&gt; is a multi purpose sdk which can be used to integrate push notifications in your app, app analytics and a whole lot of other features which you can review on its site.&lt;/p&gt;

&lt;p&gt;We are going to use &lt;strong&gt;Firebase Realtime Database&lt;/strong&gt; here to develop a simple To-do app.&lt;/p&gt;

&lt;h2 id=&quot;step-1-setting-up-xcode-project&quot;&gt;Step 1. Setting up Xcode Project&lt;/h2&gt;

&lt;p&gt;Create a new swift Xcode Project and name it TodoApp.
Now note down the &lt;strong&gt;bundle id&lt;/strong&gt;, we will need it to make the &lt;code class=&quot;highlighter-rouge&quot;&gt;GoogleService-Info&lt;/code&gt; plist file.&lt;/p&gt;

&lt;p&gt;Head over to &lt;a href=&quot;https://console.firebase.google.com/&quot;&gt;Firebase console&lt;/a&gt; and click &lt;strong&gt;Create New Project&lt;/strong&gt;. Enter TodoApp as the name project and click create project. You will be redirected to a screen like this&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/41Rq8Ij.jpg&quot; alt=&quot;Firebase Console&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Click Add firebase to your iOS project and in the popup - &lt;strong&gt;Enter your project bundle id&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/gwUb9E1.jpg&quot; alt=&quot;Bundle id popup&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Press Add app and now you will get the &lt;strong&gt;GoogleService-Info.plist&lt;/strong&gt; downloaded automatically. Now keep pressing continue to finish the integration steps and get back to the project.&lt;/p&gt;

&lt;p&gt;Drag the plist you downloaded into your project root (where .xcodeProj file is). The plist file actually includes all the relevant settings for the firebase app including the firebase database url for your app.&lt;/p&gt;

&lt;h3 id=&quot;setup-pods&quot;&gt;Setup Pods&lt;/h3&gt;

&lt;p&gt;Open a terminal and execute &lt;strong&gt;pod init&lt;/strong&gt; in your project directory. Open the pod file in text editor or in Xcode and add these pods to the todo target&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;pod &#39;Firebase&#39;
pod &#39;Firebase/Database&#39;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Run &lt;strong&gt;pod install&lt;/strong&gt; in terminal and once completed open the &lt;strong&gt;.xcworkspace&lt;/strong&gt; file to open the project.&lt;/p&gt;

&lt;h2 id=&quot;step-2-making-the-app-ui&quot;&gt;Step 2. Making the App UI&lt;/h2&gt;

&lt;p&gt;We need to setup a basic UI to actually see our firebase code in work. I am going to explain in short here with enough details to actually carry out yourself.&lt;/p&gt;

&lt;p&gt;Embed the initial view controller in a navigation controller (this gives us the navigation stack). Now add another view controller and set its storyboard id to &lt;strong&gt;ToDoVC&lt;/strong&gt;.
 The UI you need to make is shown in the screenshot&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/eN1Y4qT.jpg&quot; alt=&quot;App&#39;s UI&quot; /&gt;&lt;/p&gt;

&lt;p&gt;The first VC has a TableView and a UIBarButtonItem in it. TableView has a dynamic prototype cell and i have given cellIdentifier as &lt;strong&gt;ToDoCell&lt;/strong&gt;. Make sure to make the tableview outlet and set its delegate and data source to your VC class.&lt;/p&gt;

&lt;p&gt;The bar button just segues to the TodoViewController (our second VC in the screen).&lt;/p&gt;

&lt;p&gt;The TodoViewController has three labels and two textfields + a date picker in it. Pretty simple stuff.
 Make a new &lt;strong&gt;TodoViewController.swift&lt;/strong&gt; class in your project and assign it to the VC. Then make all the textfield and date picker outlets.
 Also add a Done/Save barbutton item in this class on which we will actually save our Todo to the firebase db. Make the appt &lt;strong&gt;IBAction&lt;/strong&gt; for it.&lt;/p&gt;

&lt;h2 id=&quot;step-3-making-the-model&quot;&gt;Step 3. Making the Model&lt;/h2&gt;

&lt;p&gt;Our Todo won’t be a Array or Dictionary lying around here and there in a project. We will make a proper model class for it.
Make a new &lt;strong&gt;Todo.swift&lt;/strong&gt; in your project and replace its content with the following&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;&lt;span class=&quot;kd&quot;&gt;import&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UIKit&lt;/span&gt;

&lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;NSObject&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;name&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;message&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;reminderDate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;
    &lt;span class=&quot;c1&quot;&gt;// id which is set from firebase to uniquely identify it&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;uniqueId&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;h2 id=&quot;step-4-back-to-understanding-how-firebase-works&quot;&gt;Step 4. Back to understanding how Firebase works&lt;/h2&gt;

&lt;p&gt;The database your app has on the firebase cloud is available on a public url like https://appname-randomIdentifer.firebaseio.com/.
Since it is public anyone can read/write to it if the url is known. To solve this the &lt;strong&gt;database rules&lt;/strong&gt; section is provided where you can change the access/write rights.&lt;/p&gt;

&lt;p&gt;By default firebase database require user to be authenticated before writing to the database.&lt;/p&gt;

&lt;h3 id=&quot;changing-database-rules&quot;&gt;Changing Database Rules&lt;/h3&gt;

&lt;p&gt;In this begginer tutorial we are going to remove the authentication required to read/write from our database. Note: &lt;strong&gt;You should not have this for a production app&lt;/strong&gt;.&lt;/p&gt;

&lt;p&gt;Go to the database section in the firebase console and change to the rules tab. Update the rules with the below and click publish.&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-json&quot; data-lang=&quot;json&quot;&gt;&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
  &lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&quot;rules&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;w&quot;&gt; &lt;/span&gt;&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
    &lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&quot;.read&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;w&quot;&gt; &lt;/span&gt;&lt;span class=&quot;kc&quot;&gt;true&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
    &lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&quot;.write&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;w&quot;&gt; &lt;/span&gt;&lt;span class=&quot;kc&quot;&gt;true&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
  &lt;/span&gt;&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;span class=&quot;w&quot;&gt;
&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/W4a6Xjm.jpg&quot; alt=&quot;Rules&quot; /&gt;&lt;/p&gt;

&lt;h2 id=&quot;database-structure&quot;&gt;Database Structure&lt;/h2&gt;

&lt;p&gt;Firebase database is actually a NoSQL
one, you won’t see any tables and where clauses in it and it is therefore &lt;strong&gt;a big change&lt;/strong&gt; for many developers out there.&lt;/p&gt;

&lt;p&gt;Our app has a simple Todo structure which arranged in a typical SQL database would look like.&lt;/p&gt;

&lt;table&gt;
  &lt;tbody&gt;
    &lt;tr&gt;
      &lt;td&gt;Name&lt;/td&gt;
      &lt;td&gt;Message&lt;/td&gt;
      &lt;td&gt;Date&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
      &lt;td&gt;First&lt;/td&gt;
      &lt;td&gt;Message&lt;/td&gt;
      &lt;td&gt;10/10/16 10:10&lt;/td&gt;
    &lt;/tr&gt;
  &lt;/tbody&gt;
&lt;/table&gt;

&lt;p&gt;But in &lt;strong&gt;Firebase JSON syntax&lt;/strong&gt;, we would have to do something like this
&lt;img src=&quot;http://i.imgur.com/rGOklwM.jpg&quot; alt=&quot;Db structure&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Each todo is uniquely identified by its key which firebase creates and our todoList is actually and array for the key &lt;strong&gt;todo&lt;/strong&gt; in our db.&lt;/p&gt;

&lt;hr /&gt;

&lt;h2 id=&quot;coding-actual-firebase-logic&quot;&gt;Coding Actual Firebase Logic&lt;/h2&gt;

&lt;h3 id=&quot;step-5-saving-a-new-todo-in-the-firebase-db&quot;&gt;Step 5. Saving a new Todo in the Firebase Db&lt;/h3&gt;

&lt;h4 id=&quot;intializing-firebase-in-our-app&quot;&gt;Intializing Firebase in our app&lt;/h4&gt;

&lt;p&gt;Open up Appdelegate.swift &lt;code class=&quot;highlighter-rouge&quot;&gt;didFinishLaunching&lt;/code&gt; method and in it add the line
&lt;code class=&quot;highlighter-rouge&quot;&gt;
        FIRApp.configure()
&lt;/code&gt;
Make sure to &lt;strong&gt;import Firebase&lt;/strong&gt; in each class you use Firebase.&lt;/p&gt;

&lt;p&gt;Now switch to TodoViewController.swift and add a optional declaration of our todo object.&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;    &lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;In the done IBAction add the following line of code&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;        &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;==&lt;/span&gt; &lt;span class=&quot;kc&quot;&gt;nil&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
        
        &lt;span class=&quot;c1&quot;&gt;// first section&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;dateFormatter&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;NSDateFormatter&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;dateFormatter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;dateFormat&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;dd/MM/yyyy hh:mm a&quot;&lt;/span&gt;
        
        &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;name&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;nameField&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;text&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;message&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;messageField&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;text&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;reminderDate&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dateFormatter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;stringFromDate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        
        &lt;span class=&quot;c1&quot;&gt;//second section&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;ref&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;FIRDatabase&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;database&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;reference&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;key&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ref&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;child&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;todoList&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;childByAutoId&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;key&lt;/span&gt;
        
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;dictionaryTodo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;name&quot;&lt;/span&gt;    &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;name&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
                               &lt;span class=&quot;s&quot;&gt;&quot;message&quot;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;message&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
                               &lt;span class=&quot;s&quot;&gt;&quot;date&quot;&lt;/span&gt;    &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;reminderDate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
        
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;childUpdates&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;/todoList/&lt;/span&gt;&lt;span class=&quot;se&quot;&gt;\(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;key&lt;/span&gt;&lt;span class=&quot;se&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dictionaryTodo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;ref&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;updateChildValues&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;childUpdates&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;withCompletionBlock&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;error&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ref&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&amp;gt;&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Void&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;in&lt;/span&gt;
               &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;navigationController&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;popViewControllerAnimated&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kc&quot;&gt;true&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;})&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Our code first section does the typical model object filling by getting the values from our outlets. You can go ahead and add validation logic here if you want. The real firebase work is done in the second section.&lt;/p&gt;

&lt;p&gt;In Second section , we get the database reference first and then try to get the “todoList” child in our db by calling &lt;code class=&quot;highlighter-rouge&quot;&gt;ref.child(&quot;todoList&quot;)&lt;/code&gt;.
Since writing to our todoList endpoint each time will just overwrite previous values, we need to get a unique key for our new todo so that we can push it for that particular key only. We call the &lt;code class=&quot;highlighter-rouge&quot;&gt;childByAutoId().key&lt;/code&gt; on our todoList endpoint.&lt;/p&gt;

&lt;p&gt;Now we need to convert our model into a dictionary since Firebase cannot save custom classes. &lt;strong&gt;NSString/NSArray/NSNumber and NSDictionary are the only supported types&lt;/strong&gt;.
On the next line we define the childUpdate model that is for /todoList/key end point =&amp;gt; set our dictionary object.
Calling the updateChildValues performs the actual operation and we can pass a callback closure to detect any error that might have occured in the request.&lt;/p&gt;

&lt;p&gt;Try running the app now and click the add button in first VC -&amp;gt; goes to TodoViewController and in it save a new Todo. Firebase console should start showing up data that we save in the app.&lt;/p&gt;

&lt;h3 id=&quot;step-6-retreiving-all-our-todo-from-the-db&quot;&gt;Step 6. Retreiving all our Todo from the DB&lt;/h3&gt;

&lt;p&gt;Firebase allow you to constantly listen to a end point for any value but in our app we only want to load data once.
ViewController code is given below :&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;    &lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;todoList&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]()&lt;/span&gt;
   
    &lt;span class=&quot;k&quot;&gt;override&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;viewWillAppear&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;animated&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Bool&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;super&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;viewWillAppear&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;animated&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;nf&quot;&gt;loadData&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    
    &lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;loadData&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;removeAll&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;ref&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;FIRDatabase&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;database&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;reference&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;ref&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;child&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;todoList&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;observeSingleEventOfType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Value&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;withBlock&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;snapshot&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;in&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;todoDict&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;snapshot&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;value&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;as?&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;AnyObject&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;k&quot;&gt;for&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;_&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todoElement&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;in&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoDict&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
                    &lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todoElement&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
                    &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
                    &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;name&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoElement&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;name&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;as?&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;
                    &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;message&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoElement&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;message&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;as?&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;
                    &lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;reminderDate&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoElement&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;date&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;as?&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;
                    &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;append&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
            &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;reloadData&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
            
          &lt;span class=&quot;p&quot;&gt;})&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;error&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;in&lt;/span&gt;
                &lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;error&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;localizedDescription&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
          &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    
    &lt;span class=&quot;c1&quot;&gt;//MARK: TableView datasource&lt;/span&gt;
    
    &lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UITableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;numberOfRowsInSection&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;section&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Int&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&amp;gt;&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;Int&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;count&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UITableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cellForRowAtIndexPath&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;indexPath&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;NSIndexPath&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&amp;gt;&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UITableViewCell&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;cell&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;dequeueReusableCellWithIdentifier&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;ToDoCell&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;cell&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;textLabel&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;text&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;indexPath&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;row&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;name&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cell&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;First we declare a array which will hold all our Todo model objects. Next we call the loadData method in our &lt;code class=&quot;highlighter-rouge&quot;&gt;viewWillAppear&lt;/code&gt; method so that our data is refreshed everytime app is launched as well as when we come back to the view after saving a new Todo.
In &lt;strong&gt;loadData&lt;/strong&gt; we get the reference to our &lt;strong&gt;todoList&lt;/strong&gt; endpoint and call the &lt;strong&gt;observeSingleEventOfType&lt;/strong&gt; method since that observes the value event only one and is not kept in memory all the time listening for any real time changes in our end point. In the closure &lt;strong&gt;snapshot.value&lt;/strong&gt; contains the value of that endpoint.&lt;/p&gt;

&lt;p&gt;If you observe the db in the console; each todo is uniquely identified by a key therefore in our case the snapshot.value is actually a dictionary with key value mapping. We cast it into a &lt;code class=&quot;highlighter-rouge&quot;&gt;[String:AnyObject]&lt;/code&gt; dictionary using if let and then enumerate it. Each object contains the name,message and date of our Todo, we fill up our model with that and add it to the array. In the end we reload tableview to show the list of Todo in our UI.&lt;/p&gt;

&lt;h3 id=&quot;step-7-viewing-existing-todo&quot;&gt;Step 7. Viewing existing Todo&lt;/h3&gt;

&lt;p&gt;We do have our todo being retrieved and the name being shown in tableview but clicking one should go to the &lt;strong&gt;TodoViewController&lt;/strong&gt; and show all details right ? So add &lt;em&gt;didSelectRow&lt;/em&gt; method in your ViewController class&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;&lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;UITableView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;didSelectRowAtIndexPath&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;indexPath&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;NSIndexPath&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;todoVC&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;storyboard&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;instantiateViewControllerWithIdentifier&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;ToDoVC&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;as!&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;ToDoViewController&lt;/span&gt;
    &lt;span class=&quot;n&quot;&gt;todoVC&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;todoList&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;indexPath&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;row&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;navigationController&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;pushViewController&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todoVC&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;animated&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;kc&quot;&gt;true&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Real simple code right there. Now you need to show those details in the outlets in your TodoViewController class. Update it with the following code&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;&lt;span class=&quot;k&quot;&gt;override&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;func&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;viewDidLoad&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;super&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;viewDidLoad&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;!=&lt;/span&gt; &lt;span class=&quot;kc&quot;&gt;nil&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;nameField&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;text&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;name&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;messageField&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;text&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;?&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;message&lt;/span&gt;
        
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;dateFormatter&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;NSDateFormatter&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;dateFormatter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;dateFormat&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;dd/MM/yyyy hh:mm a&quot;&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;date&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dateFormatter&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;dateFromString&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;todo&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;reminderDate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;datePicker&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;date&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;date&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;That’s it to have our todo app functioning on our firebase database :).&lt;/p&gt;

&lt;h2 id=&quot;conclusion&quot;&gt;Conclusion&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Thank you&lt;/strong&gt; for reading this far. For any questions you are welcome to ask in our chat room.&lt;/p&gt;

&lt;h2 id=&quot;next-steps&quot;&gt;Next Steps&lt;/h2&gt;

&lt;p&gt;Please take a look at our other &lt;a href=&quot;../../tutorials&quot;&gt;tutorials&lt;/a&gt; :)&lt;/p&gt;
</description>
        <pubDate>Mon, 30 May 2016 00:00:00 +0530</pubDate>
        <link>http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/05/todo-app-with-firebase-part-1-(Xcode)</link>
        <guid isPermaLink="true">http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/05/todo-app-with-firebase-part-1-(Xcode)</guid>
        
        <category>firebase</category>
        
        <category>swift</category>
        
        <category>ios</category>
        
        <category>tutorial</category>
        
        <category>todo app</category>
        
        
        <category>lessons</category>
        
      </item>
    
      <item>
        <title>Hello Android</title>
        <description>&lt;h1 id=&quot;part-1---theoritical-and-best-practices-for-android&quot;&gt;Part 1 - Theoritical And Best practices for Android&lt;/h1&gt;

&lt;blockquote&gt;
  &lt;p&gt;This is a general summarized version of our take on explaining Android development for you. Its by no means a complete topic that covers everything. This is to give you a good grasp of things of the framework, best practices used by us and generally a simple tutorial after which you are ready to take on any topic you are interested in Android :)&lt;/p&gt;
&lt;/blockquote&gt;

&lt;h1 id=&quot;what-is-android&quot;&gt;What is Android?&lt;/h1&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/jK415Ks.png&quot; alt=&quot;Android Logo&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Android is a open-source operating system developed by Google released in 2008 and has gone on then to become one of the most popular OS for mobile devices.&lt;br /&gt;
Apps can be developed for android in many languages including java, scala, kotlin, swift and so on.&lt;/p&gt;

&lt;h2 id=&quot;android-studio&quot;&gt;Android Studio&lt;/h2&gt;

&lt;p&gt;Android Studio is the official IDE released by Google to develop android apps. Basic interface of the studio is explained below&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/wCvWxff.jpg&quot; alt=&quot;Android Studio&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Why you should use android studio and not other IDE like eclipse/Intelli J etc ?&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;
    &lt;p&gt;&lt;strong&gt;Android Focused&lt;/strong&gt;&lt;br /&gt;
All the tools provided in android studio are meant to help in android projects. Huge templates support, layout editor etc are the features only provided in it.&lt;/p&gt;
  &lt;/li&gt;
  &lt;li&gt;
    &lt;p&gt;&lt;strong&gt;Official Support from Google&lt;/strong&gt;&lt;br /&gt;
Its the IDE which the google developers use and hence you can always expect it to be made better for developers each day.&lt;/p&gt;
  &lt;/li&gt;
&lt;/ul&gt;

&lt;h2 id=&quot;android-ui-components&quot;&gt;Android UI Components&lt;/h2&gt;

&lt;h3 id=&quot;ui-basics&quot;&gt;UI Basics&lt;/h3&gt;

&lt;p&gt;A typical Android device can be of any size and therefore you can’t simply go around thinking values in pixels. 1 pixel might be quite big in one device but very small in another. The solution is to use &lt;strong&gt;dpi(Device independent pixel)&lt;/strong&gt;. Most of the time you will hear the &lt;strong&gt;dp&lt;/strong&gt; term which is the same as dpi.
So rule of thumb is to specify size in dp instead of pixels.&lt;/p&gt;

&lt;p&gt;Common design terminologies&lt;/p&gt;

&lt;ol&gt;
  &lt;li&gt;&lt;strong&gt;wrap_content&lt;/strong&gt; : wrap content for width/height is specified when you want the layout to take as much width/height as its content.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;match_parent&lt;/strong&gt; : match parent is used when you want the view to take up all space in its parent. Using match_parent does not gaurantee full space though, OS calculates the space available and if otherview take up some space, your view will get whole view space-otherviews space height/width.&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;You define your application screen UI in xml files/graphical editor. The xml files mostly consider of using UI components provided by the framework to layout the elements on the screen. We list out the most common one used here&lt;/p&gt;

&lt;h2 id=&quot;layouts&quot;&gt;Layouts&lt;/h2&gt;
&lt;p&gt;Layouts are the UI component that controls the positioning and layout of their children. You can nest layout inside one another.&lt;/p&gt;

&lt;h3 id=&quot;linearlayout&quot;&gt;LinearLayout&lt;/h3&gt;

&lt;p&gt;Linearlayout is a commonly used layout to (as the name suggests) lay the children UI Views linearly either in a horizontal stack or a vertical.&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/B4lFtoh.jpg&quot; alt=&quot;Linear Layout&quot; /&gt;&lt;/p&gt;

&lt;h3 id=&quot;relativelayout&quot;&gt;RelativeLayout&lt;/h3&gt;

&lt;p&gt;RelativeLayout lay it children in relation to one another or to itself. You can use &lt;code class=&quot;highlighter-rouge&quot;&gt;alignParentLeft&lt;/code&gt; to make the view position at top-left and &lt;code class=&quot;highlighter-rouge&quot;&gt;alignCenterInParent&lt;/code&gt; to make view center in the whole layout.&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/NOoZprc.jpg&quot; alt=&quot;Relative Layout&quot; /&gt;&lt;/p&gt;

&lt;h3 id=&quot;framelayout&quot;&gt;FrameLayout&lt;/h3&gt;

&lt;p&gt;FrameLayout works on the z axis/order basis. Other layouts do not allow you to specify views overlapping one another however frame layout does.&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/lw3vr7p.jpg&quot; alt=&quot;Frame Layout&quot; /&gt;&lt;/p&gt;

&lt;p&gt;There are more layouts waiting to be explored like DrawerLayout, GridLayout etc but they are specific and we are not explaining them here for now. The above explained layouts are the most commonly used to design any complex UI screen you wish.&lt;/p&gt;

&lt;h2 id=&quot;activity&quot;&gt;Activity&lt;/h2&gt;

&lt;p&gt;Activity are the basic individual screen component in Android. When you launch an app, you basically open one of its screen and that is an &lt;em&gt;Activity&lt;/em&gt;. Its basically the &lt;strong&gt;controller&lt;/strong&gt; part in an MVC app.&lt;/p&gt;

&lt;h2 id=&quot;fragments&quot;&gt;Fragments&lt;/h2&gt;

&lt;p&gt;Fragments are the middleware between the controller and the view in a MVC model. Main difference b/w fragment and activity is that fragment needs to be hosted in a activity therefore they do not exist on their own. They always need to be added to an activity’s view to be shown.&lt;/p&gt;

&lt;h3 id=&quot;which-one-to-use-and-when&quot;&gt;Which one to use and when&lt;/h3&gt;

&lt;p&gt;1) Well there has to be one activity at least in your app, otherwise no UI screen can be launched.&lt;br /&gt;
2) Now, do you want the view you are designing to be launched individually or do you want everytime user to go from A-&amp;gt;B. If you want B be to be allowed to launch individually : it needs to be an activity.&lt;br /&gt;
3) Are you making a resuable view?  Well not exactly a view but a &lt;strong&gt;wrapper&lt;/strong&gt; that shows a particular view and act as its controller : &lt;strong&gt;if yes, go for a fragment&lt;/strong&gt;.&lt;/p&gt;

&lt;h2 id=&quot;intent&quot;&gt;Intent&lt;/h2&gt;
&lt;p&gt;Intent is used to communicate with other activities within the OS or within the app itself. They are at the core of the android framework. If you want to launch browser app - just create a new intent specifiying its package. If you want to open another activity of your app - create another and set the activity class and just launch the intent.&lt;/p&gt;

&lt;h2 id=&quot;manifest&quot;&gt;Manifest&lt;/h2&gt;

&lt;p&gt;Manifest is the file that describes how your app appear to the OS and in the play store. It contains certain terms that define app features, descriptions, list of activities etc.&lt;br /&gt;
App’s manifest includes these&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;&lt;strong&gt;App Package Identifier&lt;/strong&gt; - this is a identifier that uniquely identifies your app and is in the reverse domain format (com.domain.appname)&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;App name&lt;/strong&gt; - Name to be shown on user device/play store&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;Icon file&lt;/strong&gt; - Which is the icon to show in app drawer.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;List of activities&lt;/strong&gt; - Each activity/individual screen is defined in the manifest.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;Permissions&lt;/strong&gt; - Your app require maybe access to location or maybe read user contacts.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;Features&lt;/strong&gt; - Your app is defined for only call enabled devices (not tablets).&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;Min OS version supported&lt;/strong&gt; - Defines which is the OS that can install the app and none below can.&lt;/li&gt;
&lt;/ul&gt;

&lt;h1 id=&quot;gradle&quot;&gt;Gradle&lt;/h1&gt;

&lt;p&gt;Gradle is the de-facto way Google has come up with to &lt;strong&gt;maintain dependencies&lt;/strong&gt; in a project. Its kinda similar to cocoapods in iOS, npm in JS and composer in php.&lt;/p&gt;

&lt;p&gt;Your project will often contain third party code such as Facebook, Google+ or simply a lib that manages image downloads and stuff. It is tiresome to go download these files and add them to your project. Gradle solves this by maintaing the standard of dependency, you just have to add the gradle repository url for the lib you want to integrate and it will go ahead and download the files and &lt;strong&gt;configure your project&lt;/strong&gt; to make the lib work properly.&lt;br /&gt;
&lt;strong&gt;Build.gradle&lt;/strong&gt; file is used to manage this. A sample version is shown below&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;dependencies {
    compile fileTree(dir: &#39;libs&#39;, include: [&#39;*.jar&#39;])
    testCompile &#39;junit:junit:4.12&#39;
    compile &#39;com.android.support:appcompat-v7:23.3.0&#39;
    compile &#39;com.android.support:design:23.3.0&#39;
}
 &lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;h2 id=&quot;data-storage&quot;&gt;Data Storage&lt;/h2&gt;

&lt;p&gt;Data storage is a important decision in every app and Android consist of few options for it&lt;/p&gt;

&lt;ol&gt;
  &lt;li&gt;&lt;strong&gt;Shared Preference&lt;/strong&gt; : Shared preferences is the simple preferences saving api provided by the framework that can be used to store simple preferences like user name, favorite theme for your app and so on. It is not intended to be used for huge/complex objects.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;SQLite&lt;/strong&gt; : SQLite is the most used database storage by developers due to it being a RDMS. It implements the caching, query processing, transactions and a whole list of other feature you would expect a sensitive data app to have.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;Direct File Storage&lt;/strong&gt; : You can write whatever format of data with a custom blue print and read it back. Avoided by most of the developers.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;Realm&lt;/strong&gt; : A new third party library that is really similar to sqlite except its syntax is more object oriented and modern, therefore, faster development!.&lt;/li&gt;
&lt;/ol&gt;

&lt;h2 id=&quot;tipscommon-pitfalls&quot;&gt;Tips/Common Pitfalls&lt;/h2&gt;

&lt;p&gt;In this section we point across common mistakes all developers do while developing apps and maybe you can avoid them if you know them beforehand&lt;/p&gt;

&lt;ol&gt;
  &lt;li&gt;All xml and drawables can &lt;strong&gt;only use lowercase alphabets&lt;/strong&gt;. A file like &lt;em&gt;MyView.xml&lt;/em&gt; or &lt;em&gt;myImage.png&lt;/em&gt; will throw an error.&lt;/li&gt;
  &lt;li&gt;Every activity needs to be defined in manifest before using it in code. You can’t open a activity which is not declared in the app’s manifest, doing so will result in a crash.&lt;/li&gt;
  &lt;li&gt;Check if you have specified permission for the feature you are coding. Many tasks require permission from the user including even accessing the internet, make sure you have added that permission in the manifest.&lt;/li&gt;
&lt;/ol&gt;

&lt;hr /&gt;

&lt;h2 id=&quot;part-2---coding-your-first-app&quot;&gt;Part 2 - Coding your first App&lt;/h2&gt;

&lt;p&gt;Follow along to make a simple app that stores basic user basic details using input by user and persist them for next launch.&lt;/p&gt;

&lt;h3 id=&quot;create-a-new-project-in-android-studio&quot;&gt;1. Create a new project in Android Studio&lt;/h3&gt;

&lt;p&gt;Open Android Studio and click create new project from File-&amp;gt;New
&lt;img src=&quot;http://i.imgur.com/EtRgtft.jpg&quot; alt=&quot;New Project Window&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Name the project &lt;strong&gt;UserDetails&lt;/strong&gt; and continue to the next window. You might be seeing the option to choose the SDK, i have lollipop sdk installed, you can use any lollipop or marshmallow version and continue to next window.&lt;br /&gt;
Select Blank Activity template and press finish on the next screen to have default activity file name set up for you.&lt;/p&gt;

&lt;h3 id=&quot;project-structure&quot;&gt;Project Structure&lt;/h3&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/3Lgk7Bi.jpg&quot; alt=&quot;Project Structure&quot; /&gt;&lt;/p&gt;

&lt;p&gt;All your java code files reside in the &lt;strong&gt;src&lt;/strong&gt; folder while the &lt;strong&gt;res&lt;/strong&gt; folder consist of the assets including manifest, drawable/images, layout files etc.&lt;/p&gt;

&lt;p&gt;Try running the app to see the Hello World textiview ready and setup for you already.&lt;/p&gt;

&lt;h3 id=&quot;interface&quot;&gt;2. Interface&lt;/h3&gt;

&lt;p&gt;Here is what our final interface is going to look like&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/niH9V4F.jpg&quot; alt=&quot;Interface&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Open up content_main.xml and replace it with the following content&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-xml&quot; data-lang=&quot;xml&quot;&gt;&lt;span class=&quot;cp&quot;&gt;&amp;lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&amp;gt;&lt;/span&gt;
&lt;span class=&quot;nt&quot;&gt;&amp;lt;RelativeLayout&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;xmlns:android=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;http://schemas.android.com/apk/res/android&quot;&lt;/span&gt;
    &lt;span class=&quot;na&quot;&gt;xmlns:tools=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;http://schemas.android.com/tools&quot;&lt;/span&gt;
    &lt;span class=&quot;na&quot;&gt;xmlns:app=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;http://schemas.android.com/apk/res-auto&quot;&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;android:layout_width=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;match_parent&quot;&lt;/span&gt;
    &lt;span class=&quot;na&quot;&gt;android:layout_height=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;match_parent&quot;&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;android:paddingLeft=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@dimen/activity_horizontal_margin&quot;&lt;/span&gt;
    &lt;span class=&quot;na&quot;&gt;android:paddingRight=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@dimen/activity_horizontal_margin&quot;&lt;/span&gt;
    &lt;span class=&quot;na&quot;&gt;android:paddingTop=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@dimen/activity_vertical_margin&quot;&lt;/span&gt;
    &lt;span class=&quot;na&quot;&gt;android:paddingBottom=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@dimen/activity_vertical_margin&quot;&lt;/span&gt;
    &lt;span class=&quot;na&quot;&gt;app:layout_behavior=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@string/appbar_scrolling_view_behavior&quot;&lt;/span&gt;
    &lt;span class=&quot;na&quot;&gt;tools:showIn=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@layout/activity_main&quot;&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;tools:context=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;.MainActivity&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&amp;gt;&lt;/span&gt;


    &lt;span class=&quot;nt&quot;&gt;&amp;lt;ImageView&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:id=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@+id/imageView&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:src=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@android:drawable/sym_def_app_icon&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_width=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;wrap_content&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_height=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;wrap_content&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_centerHorizontal=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;true&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;


    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Button&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:id=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@+id/updateImageButton&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_below=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@id/imageView&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_centerInParent=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;true&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_width=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;wrap_content&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_height=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;wrap_content&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:text=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Update Image&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;

    &lt;span class=&quot;nt&quot;&gt;&amp;lt;LinearLayout&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_width=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;match_parent&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_height=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;wrap_content&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_below=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@id/updateImageButton&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:layout_centerHorizontal=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;true&quot;&lt;/span&gt;
        &lt;span class=&quot;na&quot;&gt;android:orientation=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;vertical&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&amp;gt;&lt;/span&gt;


        &lt;span class=&quot;nt&quot;&gt;&amp;lt;EditText&lt;/span&gt;
            &lt;span class=&quot;na&quot;&gt;android:id=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;@+id/edittext&quot;&lt;/span&gt;
            &lt;span class=&quot;na&quot;&gt;android:layout_width=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;match_parent&quot;&lt;/span&gt;
            &lt;span class=&quot;na&quot;&gt;android:layout_height=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;wrap_content&quot;&lt;/span&gt;
            &lt;span class=&quot;na&quot;&gt;android:hint=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Your Name&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;

    &lt;span class=&quot;nt&quot;&gt;&amp;lt;/LinearLayout&amp;gt;&lt;/span&gt;

&lt;span class=&quot;nt&quot;&gt;&amp;lt;/RelativeLayout&amp;gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Our root layout is a RelativeLayout. In it we add a ImageView which is centered horizontally, a button to launch the intent to get the image from user gallery aligned below it.
Then we add a vertical linear layout to just show nesting of layouts. One can simply go and put the EditText below the button by using &lt;code class=&quot;highlighter-rouge&quot;&gt;alignBelow&lt;/code&gt; but we have instead put the layout below the button and inside it put the EditText.&lt;/p&gt;

&lt;h3 id=&quot;connecting-xml-views-with-code&quot;&gt;3. Connecting Xml Views with Code&lt;/h3&gt;

&lt;p&gt;Your views have been defined in xml but we need to be able to access them in our activity file. In our &lt;code class=&quot;highlighter-rouge&quot;&gt;onCreate&lt;/code&gt; method of Activity we assign the layout to the activity with the id &lt;code class=&quot;highlighter-rouge&quot;&gt;R.layout.activity_main&lt;/code&gt;.
Replace your &lt;strong&gt;onCreate&lt;/strong&gt; method and add a few in your activity file like below&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;&lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;MainActivity&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;extends&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;AppCompatActivity&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

    &lt;span class=&quot;n&quot;&gt;ImageView&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;profileImg&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;n&quot;&gt;EditText&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;nameTxt&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;n&quot;&gt;Button&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;loadImageButton&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;

    &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;protected&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onCreate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Bundle&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;savedInstanceState&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;kd&quot;&gt;super&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;onCreate&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;savedInstanceState&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;setContentView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;layout&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;activity_main&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;n&quot;&gt;initUI&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;setActionListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;initUI&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;profileImg&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ImageView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;imageView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;nameTxt&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;EditText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;edittext&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;loadImageButton&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Button&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;findViewById&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;R&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;id&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;updateImageButton&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;setActionListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;loadImageButton&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setOnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;View&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;OnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onClick&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;View&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;view&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                
            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;});&lt;/span&gt;
        
        &lt;span class=&quot;n&quot;&gt;nameTxt&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;addTextChangedListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TextWatcher&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;beforeTextChanged&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CharSequence&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;charSequence&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;i&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;i1&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;i2&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

            &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onTextChanged&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CharSequence&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;charSequence&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;i&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;i1&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;i2&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

            &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;afterTextChanged&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Editable&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;editable&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;});&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;We declare few variables at the start so that we can refer them globally inside our class. Now in our &lt;code class=&quot;highlighter-rouge&quot;&gt;onCreate&lt;/code&gt; we set the contentView and then try to hook up the connections in the &lt;code class=&quot;highlighter-rouge&quot;&gt;initUI()&lt;/code&gt; function we added. Do note that trying to setup connections before calling the appt &lt;strong&gt;setContentView&lt;/strong&gt; call will result in a crash.&lt;/p&gt;

&lt;p&gt;&lt;code class=&quot;highlighter-rouge&quot;&gt;initUI&lt;/code&gt; method calls findViewById method to find the respective view with the id we set it in xml and then we cast it to the specific type we have made it. 
Next we want to have the button do something on the click, so we make a &lt;code class=&quot;highlighter-rouge&quot;&gt;setActionListener&lt;/code&gt; method and assign a onClickListener to the loadImageButton and a TextWatcher to our nameTxt to listen for events of text changing.&lt;/p&gt;

&lt;h3 id=&quot;saving-user-input&quot;&gt;4. Saving User Input&lt;/h3&gt;

&lt;p&gt;In our &lt;code class=&quot;highlighter-rouge&quot;&gt;TextWatcher&lt;/code&gt; afterTextChanged method, add the following code&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;  &lt;span class=&quot;n&quot;&gt;SharedPreferences&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;Editor&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;editor&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;PreferenceManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getDefaultSharedPreferences&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;getApplicationContext&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()).&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;edit&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
  &lt;span class=&quot;n&quot;&gt;editor&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;putString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;name&quot;&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;nameTxt&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;toString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
  &lt;span class=&quot;n&quot;&gt;editor&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;commit&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;This uses the SharedPreferences API we talked about earlier in part 1. We get the default sharedPref and get a Editor, in which we then put the text of our nameTxt content and commit the changes.&lt;/p&gt;

&lt;h3 id=&quot;getting-user-image&quot;&gt;5. Getting User Image&lt;/h3&gt;

&lt;p&gt;We will be getting the user image from the gallery of the phone and for that we need to use a &lt;code class=&quot;highlighter-rouge&quot;&gt;ACTION_GET_CONTENT&lt;/code&gt; intent. Our code needs to be updated with the following new function and variables&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt; &lt;span class=&quot;c1&quot;&gt;// declare two new variables at the global level&lt;/span&gt;
  &lt;span class=&quot;n&quot;&gt;Uri&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;imageUri&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
  &lt;span class=&quot;kd&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;static&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;final&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;PICTURE_REQUEST_CODE&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;100&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;
  
 &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;openPictureSelector&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;intent&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setType&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;image/*&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setAction&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;ACTION_GET_CONTENT&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;startActivityForResult&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;createChooser&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;intent&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;Select picture&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;),&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;PICTURE_REQUEST_CODE&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
  &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;

  &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
    &lt;span class=&quot;kd&quot;&gt;protected&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onActivityResult&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;requestCode&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;resultCode&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Intent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;data&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;kd&quot;&gt;super&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;onActivityResult&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;requestCode&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;resultCode&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;data&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;switch&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;requestCode&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;case&lt;/span&gt; &lt;span class=&quot;nl&quot;&gt;PICTURE_REQUEST_CODE:&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;resultCode&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;==&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;RESULT_OK&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;

                    &lt;span class=&quot;n&quot;&gt;imageUri&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;data&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getData&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
                    &lt;span class=&quot;k&quot;&gt;try&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                        &lt;span class=&quot;n&quot;&gt;Bitmap&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;imageBitmap&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;MediaStore&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;Images&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;Media&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getBitmap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getContentResolver&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(),&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;imageUri&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
                        &lt;span class=&quot;n&quot;&gt;profileImg&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setImageBitmap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;imageBitmap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;

                    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;catch&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IOException&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;e&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                        &lt;span class=&quot;n&quot;&gt;e&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;printStackTrace&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
                    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
                    &lt;span class=&quot;k&quot;&gt;break&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;;&lt;/span&gt;

                &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;To store the image path we make a imageUri variable and make a static int variable that will be used to hold our unique code for our image pick intent. Making int for request code of intent are common practice since it improves readability rather than you simply using random integer values around your code.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;OpenPictureSelector&lt;/strong&gt; method starts the intent to get new image. We override a method &lt;strong&gt;onActivityResult&lt;/strong&gt; in our activity which is called when a different activity returns a result/data to the current one.
We get the data from the resultIntent data and get the image from the Uri and set that to our imageView.
Call the method inside the clickListener of the loadImageButton.&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;&lt;span class=&quot;n&quot;&gt;loadImageButton&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setOnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;View&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;OnClickListener&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;nd&quot;&gt;@Override&lt;/span&gt;
            &lt;span class=&quot;kd&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;onClick&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;View&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;view&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;openPictureSelector&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;});&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Try running the app and you clicking the update image button, after selecting a image in gallery or capturing one the image would update it inside your apps as well.&lt;/p&gt;

&lt;h3 id=&quot;persisting-image-path-and-loading-values-on-next-launch&quot;&gt;6. Persisting image path and loading values on next launch&lt;/h3&gt;

&lt;p&gt;To persist the imagePath update your onActivityResult method ‘try’ block with&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;  &lt;span class=&quot;n&quot;&gt;SharedPreferences&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;Editor&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;editor&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;PreferenceManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getDefaultSharedPreferences&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;getApplicationContext&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()).&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;edit&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
  &lt;span class=&quot;n&quot;&gt;editor&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;putString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;image&quot;&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;loadImageButton&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;toString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
  &lt;span class=&quot;n&quot;&gt;editor&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;commit&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Now we have got everything working except the app doesnt load previous values we saved on launch.&lt;/p&gt;

&lt;p&gt;Time to add new method and call it in onCreate&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-java&quot; data-lang=&quot;java&quot;&gt;    &lt;span class=&quot;kd&quot;&gt;protected&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;onCreate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Bundle&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;savedInstanceState&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
       &lt;span class=&quot;c1&quot;&gt;// prev code&lt;/span&gt;
       &lt;span class=&quot;n&quot;&gt;loadDetails&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;


    &lt;span class=&quot;kt&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;loadDetails&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;SharedPreferences&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;preferences&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;PreferenceManager&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getDefaultSharedPreferences&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;getApplicationContext&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;());&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;preferences&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;contains&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;name&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;))&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;nameTxt&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setText&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;preferences&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;name&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;));&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;imageUri&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Uri&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;parse&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;preferences&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;getString&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;image&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;&quot;&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;));&lt;/span&gt;

            &lt;span class=&quot;k&quot;&gt;try&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;Bitmap&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;bitmap&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;BitmapFactory&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;decodeStream&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;getContentResolver&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;openInputStream&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;imageUri&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;));&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;profileImg&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;setImageBitmap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;bitmap&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;catch&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;FileNotFoundException&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;e&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;e&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;na&quot;&gt;printStackTrace&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;();&lt;/span&gt;
            &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;o&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;That’s all we need to do, the method tries to find if our name key exist previously in pref and then set the text by retreiving value for it. We also load the imageUri and then get the bitmap from the path afterwhich it is set to the imageView.&lt;/p&gt;

&lt;h2 id=&quot;conclusion&quot;&gt;Conclusion&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Thank you&lt;/strong&gt; for reading this far. Hopefully you have learned many helpful tips along the way and are now ready for your Android journey :).
For any questions you are welcome to ask in our chat room.&lt;/p&gt;

&lt;h2 id=&quot;next-steps&quot;&gt;Next Steps&lt;/h2&gt;

&lt;p&gt;Please take a look at our other &lt;a href=&quot;../../tutorials&quot;&gt;tutorials&lt;/a&gt; :)&lt;/p&gt;
</description>
        <pubDate>Thu, 26 May 2016 00:00:00 +0530</pubDate>
        <link>http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/05/hello-android</link>
        <guid isPermaLink="true">http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/05/hello-android</guid>
        
        <category>intro</category>
        
        <category>beginner</category>
        
        <category>android</category>
        
        <category>tutorial</category>
        
        
        <category>lessons</category>
        
      </item>
    
      <item>
        <title>How To Debug App In Xcode</title>
        <description>&lt;h2 id=&quot;what-is-debugging&quot;&gt;What is Debugging?&lt;/h2&gt;
&lt;p&gt;Debugging is the &lt;em&gt;process of finding bugs in your apps and removing them&lt;/em&gt;. A bug can be considered anything from a simple semicolon error to a whole logical mistake in your code.&lt;/p&gt;

&lt;h3 id=&quot;why-do-you-need-to-learn-debugging&quot;&gt;Why do you need to learn debugging&lt;/h3&gt;
&lt;p&gt;It is a known fact that every developer spends more time figuring out why things aren’t working in their code rather than developing it.&lt;br /&gt;
If you learn the art of debugging, you will be able to considerably reduce your time spent on fixing things… Sounds Perfect!.&lt;/p&gt;

&lt;h2 id=&quot;lets-start&quot;&gt;Lets Start&lt;/h2&gt;

&lt;p&gt;Go Ahead and download the basic project i have setup for you which we will follow along from the &lt;a href=&quot;https://github.com/Shubhank101/iOSAndroidChaosOverFlow-Projects&quot;&gt;github&lt;/a&gt; repository.&lt;br /&gt;
Its developed in Xcode 7.3 and swift 2, so make sure to have them ready.&lt;/p&gt;

&lt;p&gt;The folder contains both the apps &lt;em&gt;to be debugged&lt;/em&gt; and the working example for you to go through. 
Its a really simple two view Controllers code. The first calls the itunes search api to find list of games with keyword &lt;em&gt;fifa&lt;/em&gt; and the next view controller just loads the game image.&lt;/p&gt;

&lt;hr /&gt;

&lt;h1 id=&quot;time-to-debug&quot;&gt;Time to debug&lt;/h1&gt;

&lt;h3 id=&quot;xcode-debugging-panel&quot;&gt;Xcode Debugging Panel&lt;/h3&gt;
&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/kGd0APL.jpg&quot; alt=&quot;Breakpoints in Xcode&quot; /&gt;&lt;/p&gt;

&lt;p&gt;I have shown the main interface provided by Xcode for debugging your app. It is divided into three parts; Debug panel, Variables panel and the Console.&lt;/p&gt;

&lt;h3 id=&quot;debug-panel&quot;&gt;Debug Panel&lt;/h3&gt;

&lt;h4 id=&quot;breakpoints&quot;&gt;Breakpoints&lt;/h4&gt;
&lt;p&gt;Breakpoint are used to break/pause your code at a certain point of condition (can be a line or a complex expression). They are extremely useful as you can pause your code and inspect the values to find any mistakes in your logic/program.&lt;/p&gt;

&lt;ol&gt;
  &lt;li&gt;&lt;strong&gt;Toggle Breakpoints&lt;/strong&gt; This is a easy switch to disable all breakpoints/enable them at once.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;Play/Pause&lt;/strong&gt; This button lets you pause your code at a certain time and once you are ready to continue, just press it again to continue execution.&lt;/li&gt;
  &lt;li&gt;&lt;strong&gt;Step Over&lt;/strong&gt; Step over is the most important and most used tool in debugging for me. What it does is process the current line of code and then stop the thread at the next line, so essentially you use it to execute and debug your code line by line.&lt;/li&gt;
&lt;/ol&gt;

&lt;h3 id=&quot;variables-inspector&quot;&gt;Variables Inspector&lt;/h3&gt;
&lt;p&gt;Variables Inspector as the name suggest allow you to check and inspect values.
The variables are categorized by scope (auto and local).
&lt;strong&gt;Primitive&lt;/strong&gt; data types show the value right next to them while the &lt;em&gt;Objects&lt;/em&gt; inner variables can be checked by using the dropdown right next to them.&lt;/p&gt;

&lt;h3 id=&quot;console&quot;&gt;Console&lt;/h3&gt;
&lt;p&gt;Console shows all the logs you have added in your code using &lt;code class=&quot;highlighter-rouge&quot;&gt;print()&lt;/code&gt; function. Moreover you can use &lt;strong&gt;po &amp;lt;varName&amp;gt;&lt;/strong&gt; in console to output any variable which is currently in scope (A really handy thing).&lt;/p&gt;

&lt;hr /&gt;

&lt;h2 id=&quot;running-the-project&quot;&gt;Running the Project&lt;/h2&gt;

&lt;p&gt;Open the project and press &lt;strong&gt;Run&lt;/strong&gt;.&lt;br /&gt;
&lt;img src=&quot;http://i.imgur.com/x5jrAlv.png&quot; alt=&quot;First Error&quot; /&gt;
Well, there you go. Your first error in action.&lt;/p&gt;

&lt;p&gt;So how to proceed ?
The error points to a mutating member on a immutable object. If you already know the error and its fix, just go ahead and fix it yourself. However, in case if you dont know how to fix, its time for you to Google!.&lt;/p&gt;

&lt;h1 id=&quot;google&quot;&gt;Google&lt;/h1&gt;
&lt;p&gt;This is the &lt;strong&gt;most used&lt;/strong&gt; debugging technique used by programmers i.e Googling the error for a possible solution.&lt;br /&gt;
From a novice to a experienced programmer, everyone has to take help of google to find the cause of the error.&lt;/p&gt;

&lt;p&gt;Go ahead and copy paste &lt;code class=&quot;highlighter-rouge&quot;&gt;cannot use mutating member on immutable value; is a let constant&lt;/code&gt; into google search.  &lt;br /&gt;
You would have seen that i removed &lt;code class=&quot;highlighter-rouge&quot;&gt;appList&lt;/code&gt; from my search. Since google would try to search for the string and the possibility exist that the other sources might not have the same variable name, it is advised to remove any string from your search which might be dynamic (different to each user).&lt;/p&gt;

&lt;h3 id=&quot;reading-result&quot;&gt;Reading Result&lt;/h3&gt;

&lt;p&gt;First few results include a link to this &lt;a href=&quot;http://stackoverflow.com/questions/32232007/immutable-value-of-array-only-has-mutating-members-named-append&quot;&gt;Stackoverflow thread&lt;/a&gt;.
From the answers, you will find that&lt;/p&gt;

&lt;blockquote&gt;
  &lt;p&gt;When you use let you cannot change or append or add new things to this variable. change &lt;strong&gt;let&lt;/strong&gt; to &lt;strong&gt;var&lt;/strong&gt;&lt;/p&gt;
&lt;/blockquote&gt;

&lt;p&gt;Thats it. Change the declaration of &lt;code class=&quot;highlighter-rouge&quot;&gt;appList&lt;/code&gt; variable from let to var and your project should run this time.&lt;/p&gt;

&lt;hr /&gt;

&lt;p&gt;After running, you should be seeing many rows with fifa in their title. Click any of them and you will be treated with another error.&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/gyBXWaG.jpg&quot; alt=&quot;Next Error&quot; /&gt;&lt;/p&gt;

&lt;h2 id=&quot;stack-traces&quot;&gt;Stack Traces&lt;/h2&gt;

&lt;p&gt;First thing to do would be searching for the &lt;strong&gt;SIGBART&lt;/strong&gt; error but you will soon realise that the error is vague and you wont really be able to solve this with this less info.&lt;br /&gt;
You switch to stack traces this time. Stack trace is the stack of method calls that the program took to reach current function call. It helps to really see how the program logic has been executed by checking the function calls.&lt;br /&gt;
Luckily, in this crash, you already got the exception and the stack trace in the console.&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;&lt;span class=&quot;kt&quot;&gt;NSUnknownKeyException&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;reason&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Debug_App&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;ShowImageViewController&lt;/span&gt; &lt;span class=&quot;mh&quot;&gt;0x7ffb73c515d0&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;setValue&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;forUndefinedKey&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:]:&lt;/span&gt;
&lt;span class=&quot;n&quot;&gt;this&lt;/span&gt; &lt;span class=&quot;kd&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;is&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;not&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;key&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;value&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;coding&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;compliant&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;for&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;the&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;key&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;randomLabelOutlet&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;
&lt;span class=&quot;o&quot;&gt;***&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;First&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;throw&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;call&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;stack&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;0&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;CoreFoundation&lt;/span&gt;                      &lt;span class=&quot;mh&quot;&gt;0x000000010768fe65&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;__exceptionPreprocess&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;165&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;1&lt;/span&gt;   &lt;span class=&quot;n&quot;&gt;libobjc&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;A&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;dylib&lt;/span&gt;                     &lt;span class=&quot;mh&quot;&gt;0x00000001093d2deb&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;objc_exception_throw&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;48&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;2&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;CoreFoundation&lt;/span&gt;                      &lt;span class=&quot;mh&quot;&gt;0x000000010768faa9&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;NSException&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;raise&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;9&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;3&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;Foundation&lt;/span&gt;                          &lt;span class=&quot;mh&quot;&gt;0x0000000107a599bb&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;NSObject&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;NSKeyValueCoding&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;setValue&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;forKey&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;288&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;4&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;UIKit&lt;/span&gt;                               &lt;span class=&quot;mh&quot;&gt;0x000000010803d320&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;UIViewController&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;setValue&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;forKey&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;88&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;5&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;UIKit&lt;/span&gt;                               &lt;span class=&quot;mh&quot;&gt;0x000000010826bf41&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;UIRuntimeOutletConnection&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;connect&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;109&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;6&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;CoreFoundation&lt;/span&gt;                      &lt;span class=&quot;mh&quot;&gt;0x00000001075d04a0&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;NSArray&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;makeObjectsPerformSelector&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;224&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;7&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;UIKit&lt;/span&gt;                               &lt;span class=&quot;mh&quot;&gt;0x000000010826a924&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;UINib&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;instantiateWithOwner&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;options&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;1864&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;8&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;UIKit&lt;/span&gt;                               &lt;span class=&quot;mh&quot;&gt;0x0000000108043eea&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;UIViewController&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;_loadViewFromNibNamed&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;nv&quot;&gt;bundle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;381&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;9&lt;/span&gt;   &lt;span class=&quot;kt&quot;&gt;UIKit&lt;/span&gt;                               &lt;span class=&quot;mh&quot;&gt;0x0000000108044816&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;UIViewController&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;loadView&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;178&lt;/span&gt;
	&lt;span class=&quot;mi&quot;&gt;10&lt;/span&gt;  &lt;span class=&quot;kt&quot;&gt;UIKit&lt;/span&gt;                               &lt;span class=&quot;mh&quot;&gt;0x0000000108044b74&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;-&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;UIViewController&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;loadViewIfRequired&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;+&lt;/span&gt;
  &lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;If you will read from bottom to top. you will see that &lt;code class=&quot;highlighter-rouge&quot;&gt;loadView&lt;/code&gt; method is called and then during &lt;code class=&quot;highlighter-rouge&quot;&gt;UIRuntimeOutletConnection&lt;/code&gt; class method a crash occurs.
This is why stack trace is helpful as it gives you hint to proceed further by telling you the method calls that took place.
The current exception points to &lt;strong&gt;class is not key value coding-compliant for the key randomLabelOutlet&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;With this much info, we are ready to solve this one. If you will google for the exception error, you will come across many threads that also points to some outlet connection being broken.
To solve this, we are going to search for &lt;code class=&quot;highlighter-rouge&quot;&gt;randomLabelOutlet&lt;/code&gt; in our project.
And there it is.&lt;br /&gt;
&lt;img src=&quot;http://i.imgur.com/JAqA8kC.jpg&quot; alt=&quot;Search Result&quot; /&gt;&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/fjRsCFg.png&quot; alt=&quot;Broken Outlet&quot; /&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Remove the broken outlet&lt;/strong&gt; and now clicking the first row in tableview would work in the app.&lt;/p&gt;

&lt;hr /&gt;

&lt;h1 id=&quot;logical-errors&quot;&gt;Logical Errors&lt;/h1&gt;

&lt;p&gt;These are the creepy ones and we have &lt;strong&gt;one&lt;/strong&gt; in our project :D&lt;br /&gt;
Run the project and try clicking any of the bottom rows in the list. This time you will be faced with this
&lt;img src=&quot;http://i.imgur.com/Sgipdlt.jpg&quot; alt=&quot;image url nil&quot; /&gt;&lt;/p&gt;

&lt;p&gt;A simple google search will show that you need to use &lt;strong&gt;if let&lt;/strong&gt; for optionals unwrapping but the point here is that why is our &lt;strong&gt;imageURL&lt;/strong&gt; nil in the first place!. It definitely works for the first result of the table.&lt;/p&gt;

&lt;h3 id=&quot;app-flow&quot;&gt;App Flow&lt;/h3&gt;
&lt;p&gt;Here is a basic recap of what the app does. The first VC downloads the app results for the tag &lt;strong&gt;fifa&lt;/strong&gt; and in the second VC we just download the image from the app icon url and set it in a imageView.&lt;/p&gt;

&lt;h3 id=&quot;how-to-proceed&quot;&gt;How to proceed&lt;/h3&gt;

&lt;p&gt;1) Set breakpoint on the &lt;code class=&quot;highlighter-rouge&quot;&gt;print(imageURL)&lt;/code&gt; line
&lt;img src=&quot;http://i.imgur.com/iEkf9BL.png&quot; alt=&quot;Breakpoint added&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Run the code and try any of the last rows in the table or the first few rows.&lt;br /&gt;
For the first few rows, the value in values inspector shows like&lt;/p&gt;

&lt;p&gt;&lt;img src=&quot;http://i.imgur.com/LaGsMzf.jpg&quot; alt=&quot;First Image result&quot; /&gt;
___&lt;/p&gt;

&lt;p&gt;For the last few rows :
&lt;img src=&quot;http://i.imgur.com/NHYCYZ9.jpg&quot; alt=&quot;Second Image result&quot; /&gt;
___&lt;/p&gt;

&lt;p&gt;2) Checking the source&lt;br /&gt;
As you can see image url is for some weird reason &lt;strong&gt;nil&lt;/strong&gt; for the last rows.
To solve it, we need to think back in our code and check where is the image url set from.
Our code sets it in the &lt;code class=&quot;highlighter-rouge&quot;&gt;prepareForSegue&lt;/code&gt; method in firstVC&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;       &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;destinationVC&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;segue&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;destinationViewController&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;as?&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;ShowImageViewController&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;indexPath&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;tableView&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;indexPathForSelectedRow&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;destinationVC&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;imageURL&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;appList&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;indexPath&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;!.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;row&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;url&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Seems nothing wrong here, it just get the data from the appList variable and set the url. This forces us to check if our &lt;strong&gt;appList&lt;/strong&gt; variable actually contains proper data.
Search for the appList variable and you will soon come to source&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;  &lt;span class=&quot;k&quot;&gt;for&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;index&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;gameDict&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;in&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;arr&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;enumerate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
      &lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;model&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;AppModel&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
      &lt;span class=&quot;n&quot;&gt;model&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;name&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;gameDict&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;trackCensoredName&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;as!&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;

      &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;index&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt; &lt;span class=&quot;mi&quot;&gt;10&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
          &lt;span class=&quot;n&quot;&gt;model&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;url&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;gameDict&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;artworkUrl512&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;as?&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;                            
      &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
      &lt;span class=&quot;k&quot;&gt;self&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;appList&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;append&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;model&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;

  &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;There it is.. you see &lt;strong&gt;if(index &amp;lt;10)&lt;/strong&gt; .. that is the culprit and removing that if condition will make this project work as it was intended to.&lt;/p&gt;

&lt;h2 id=&quot;conclusion&quot;&gt;Conclusion&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Thank you&lt;/strong&gt; for reading this far. Hopefully you would have learned some helpful tips from this tutorial and are a debug ninja now.
For any questions you are welcome to ask in our chat room.&lt;/p&gt;

&lt;h3 id=&quot;for-further-info&quot;&gt;For further info&lt;/h3&gt;

&lt;p&gt;&lt;a href=&quot;https://developer.apple.com/support/debugging/&quot;&gt;Apple Debugging Support&lt;/a&gt;&lt;/p&gt;

&lt;h2 id=&quot;next-steps&quot;&gt;Next Steps&lt;/h2&gt;

&lt;p&gt;Please take a look at our other &lt;a href=&quot;../../tutorials&quot;&gt;tutorials&lt;/a&gt; :)&lt;/p&gt;
</description>
        <pubDate>Mon, 16 May 2016 00:00:00 +0530</pubDate>
        <link>http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/05/how-to-debug-app-in-xcode</link>
        <guid isPermaLink="true">http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/05/how-to-debug-app-in-xcode</guid>
        
        <category>debug</category>
        
        <category>Xcode</category>
        
        <category>swift</category>
        
        <category>tutorial</category>
        
        
        <category>lessons</category>
        
      </item>
    
      <item>
        <title>Hello Swift</title>
        <description>&lt;h1 id=&quot;what-is-swift&quot;&gt;What is Swift?&lt;/h1&gt;

&lt;p&gt;Swift is a new Apple open-source language used to develop iOS Apps.
It is open source and available now on &lt;a href=&quot;https://github.com/apple/swift&quot;&gt;GitHub&lt;/a&gt;; replacing Objective-C as the main language for the iOS and OSX platforms.&lt;/p&gt;

&lt;p&gt;The advantages of Swift over Objective-C are:&lt;/p&gt;

&lt;ol&gt;
  &lt;li&gt;Faster - Swift apps compile faster then their obj-c counterparts.&lt;/li&gt;
  &lt;li&gt;Safe   - Safe - Swift focuses a lot on ‘let’ and ‘var’ which makes the code safe by avoiding any unintended overwrite of values.&lt;/li&gt;
  &lt;li&gt;Strong - Swift supports generic, enums and a lot of new features which makes it a better language to develop in.&lt;/li&gt;
&lt;/ol&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;&lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;helloWorld&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;Hello World&quot;&lt;/span&gt;
&lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;helloWorld&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;h2 id=&quot;first-project&quot;&gt;First Project&lt;/h2&gt;
&lt;p&gt;Its time to dive right into exploring swift. Lets get started&lt;/p&gt;

&lt;h3 id=&quot;open-xcode-and-create-a-new-playground&quot;&gt;Open Xcode and create a new playground&lt;/h3&gt;
&lt;p&gt;We will be using the playground to learn basic swift before progressing on to make an app.
Go Ahead create a new playground from the &lt;strong&gt;File-&amp;gt;New&lt;/strong&gt; option.&lt;br /&gt;
First screen shall look like this
&lt;img src=&quot;http://i.imgur.com/QOSeJQV.jpg&quot; alt=&quot;Playground&quot; /&gt;&lt;/p&gt;

&lt;p&gt;Replace the contents with the following&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;&lt;span class=&quot;c1&quot;&gt;// this is a let variable which is constanct and cant be changed once after initialized&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;helloWorld&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;Hello World&quot;&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;anotherVar&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;This is another variable whose value can be changed&quot;&lt;/span&gt;

&lt;span class=&quot;c1&quot;&gt;//Uncommenting below line will throw a error&lt;/span&gt;
&lt;span class=&quot;c1&quot;&gt;//helloWorld = &quot;Changing value not allowed for let&quot;&lt;/span&gt;

&lt;span class=&quot;n&quot;&gt;anotherVar&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;Now i have a new value&quot;&lt;/span&gt;

&lt;span class=&quot;c1&quot;&gt;//ARRAYS&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;myArr&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;First String&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;Second String&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;Third String&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;];&lt;/span&gt;
&lt;span class=&quot;c1&quot;&gt;// access any value of array using the square brackets&lt;/span&gt;
&lt;span class=&quot;nf&quot;&gt;print&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;myArr&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;mi&quot;&gt;0&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;])&lt;/span&gt; &lt;span class=&quot;c1&quot;&gt;// 0,1,2 any can be used&lt;/span&gt;

&lt;span class=&quot;c1&quot;&gt;//DICTIONARY&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;myDict&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Dictionary&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;String&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;Any&lt;/span&gt;&lt;span class=&quot;o&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Key&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;AB&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;SecondKey&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;mi&quot;&gt;1&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
&lt;span class=&quot;n&quot;&gt;myDict&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Key&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
&lt;span class=&quot;n&quot;&gt;myDict&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;newKey&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;newValue&quot;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;h3 id=&quot;let-and-var&quot;&gt;let and var&lt;/h3&gt;
&lt;p&gt;Swift focuses majorly on let and var variables. 
variables defined using let are constant and cannot be changed once a value is initalized to them while the var can be changed later on.&lt;br /&gt;
This introduces a focus on making the code secure with correct usage of constant variable from the start, therefore no bugs later on.&lt;/p&gt;

&lt;h3 id=&quot;array&quot;&gt;Array&lt;/h3&gt;
&lt;p&gt;Array are defined using the square brackets []. Here we pass few values to initalize it.
Each value can be accessed using its &lt;strong&gt;index&lt;/strong&gt;.&lt;/p&gt;

&lt;h3 id=&quot;dictionary&quot;&gt;Dictionary&lt;/h3&gt;
&lt;p&gt;Dictionary is a &lt;strong&gt;key value object&lt;/strong&gt; and is used when the data has to be fetched key based.&lt;br /&gt;
Common example is for a user, you dont want to have user name at 0 index, birthday at 1. This is problematic and confusing.&lt;br /&gt;
What you want is username key to have the name value and user_birthday to have the birthday value. Something like :&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-swift&quot; data-lang=&quot;swift&quot;&gt;&lt;span class=&quot;k&quot;&gt;let&lt;/span&gt; &lt;span class=&quot;nv&quot;&gt;userDict&lt;/span&gt; &lt;span class=&quot;o&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;username&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Shubhank&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;birthday&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;unknown&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Go Ahead and check the playground to see all this live. We have added comments there for you to understand along.&lt;/p&gt;

&lt;h2 id=&quot;conclusion&quot;&gt;Conclusion&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Thank you&lt;/strong&gt; for reading this far. For any questions you are welcome to ask in our chat room.&lt;/p&gt;

&lt;h2 id=&quot;next-steps&quot;&gt;Next Steps&lt;/h2&gt;

&lt;p&gt;Please take a look at our other &lt;a href=&quot;../../tutorials&quot;&gt;tutorials&lt;/a&gt; :)&lt;/p&gt;
</description>
        <pubDate>Thu, 12 May 2016 00:00:00 +0530</pubDate>
        <link>http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/05/hello-swift</link>
        <guid isPermaLink="true">http://shubhank101.github.io/iOSAndroidChaosOverFlow/2016/05/hello-swift</guid>
        
        <category>intro</category>
        
        <category>beginner</category>
        
        <category>swift</category>
        
        <category>tutorial</category>
        
        
        <category>lessons</category>
        
      </item>
    
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