Basic Implementation of Room

app/build.gradle

@@ -2,6 +2,7 @@ plugins {
     id 'com.android.application'
     id 'kotlin-android'
     id 'com.google.gms.google-services'
+    id 'kotlin-kapt'
 }
 
 android {
@@ -87,4 +88,6 @@ dependencies {
     implementation "io.ktor:ktor-client-cio:$ktor_version"
     implementation "io.ktor:ktor-client-content-negotiation:$ktor_version"
     implementation "io.ktor:ktor-serialization-gson:$ktor_version"
+    implementation "androidx.room:room-runtime:$room_version"
+    kapt("androidx.room:room-compiler:$room_version")
 }

app/src/main/java/com/cookit/AppModule.kt

@@ -2,10 +2,11 @@ package com.cookit
 
 import com.cookit.service.IRecipeService
 import com.cookit.service.KtorRecipeService
+import org.koin.android.ext.koin.androidApplication
 import org.koin.androidx.viewmodel.dsl.viewModel
 import org.koin.dsl.module
 
 val appModule = module {
     viewModel { MainViewModel(get()) }
-    single<IRecipeService> { KtorRecipeService() }
+    single<IRecipeService> { KtorRecipeService(androidApplication()) }
 }

app/src/main/java/com/cookit/MainViewModel.kt

@@ -13,7 +13,6 @@ import com.cookit.dto.Photo
 import com.cookit.dto.Recipe
 import com.cookit.dto.User
 import com.cookit.service.IRecipeService
-import com.cookit.service.KtorRecipeService
 import com.cookit.service.TextFieldIngredientMapService
 import com.google.firebase.firestore.FirebaseFirestore
 import com.google.firebase.firestore.FirebaseFirestoreSettings
@@ -24,12 +23,12 @@ import kotlinx.coroutines.launch
  * Class for the primary view model
  * Used to supply [MutableLiveData] to views
  */
-class MainViewModel(var recipeService: IRecipeService = KtorRecipeService()) : ViewModel() {
+class MainViewModel(var recipeService: IRecipeService) : ViewModel() {
 
     val photos: ArrayList<Photo> = ArrayList()
     var user: User? = null
     val NEW_RECIPE = "New Recipe"
-    val recipes: MutableLiveData<ArrayList<Recipe>> = MutableLiveData<ArrayList<Recipe>>()
+    val recipes = recipeService.getRecipeDAO().getAllRecipes()
     val userRecipes: MutableLiveData<ArrayList<Recipe>> = MutableLiveData<ArrayList<Recipe>>()
     var selectedRecipe by mutableStateOf(Recipe())
     val ingredientMapper = TextFieldIngredientMapService()
@@ -70,9 +69,7 @@ class MainViewModel(var recipeService: IRecipeService = KtorRecipeService()) : V
 
     internal fun fetchRecipes() {
         viewModelScope.launch {
-            val innerRecipeList = recipeService.fetchRecipes()
-            val innerRecipes: ArrayList<Recipe> = innerRecipeList?.recipes ?: ArrayList()
-            recipes.postValue(innerRecipes)
+            recipeService.fetchRecipes()
         }
     }
 
@@ -176,7 +173,6 @@ class MainViewModel(var recipeService: IRecipeService = KtorRecipeService()) : V
                 }
                 else -> return listOf()
             }
-        }
-        return listOf()
+        } ?: return listOf()
     }
 }

app/src/main/java/com/cookit/dao/IRecipeDAO.kt

@@ -0,0 +1,17 @@
+package com.cookit.dao
+
+import androidx.lifecycle.LiveData
+import androidx.room.*
+import com.cookit.dto.Recipe
+
+@Dao
+interface IRecipeDAO {
+    @Query("SELECT * FROM recipe")
+    fun getAllRecipes(): LiveData<List<Recipe>>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun insertAll(recipes: ArrayList<Recipe>)
+
+    @Delete
+    fun delete(recipe: Recipe)
+}

app/src/main/java/com/cookit/dao/RecipeDatabase.kt

@@ -0,0 +1,13 @@
+package com.cookit.dao
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import androidx.room.TypeConverters
+import com.cookit.dto.Recipe
+import com.cookit.service.StringMapConverter
+
+@Database(entities = [Recipe::class], version = 1)
+@TypeConverters(StringMapConverter::class)
+abstract class RecipeDatabase : RoomDatabase() {
+    abstract fun recipeDao(): IRecipeDAO
+}

app/src/main/java/com/cookit/dto/Recipe.kt

@@ -1,19 +1,24 @@
 package com.cookit.dto
 
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.Ignore
+import androidx.room.PrimaryKey
 import com.google.gson.annotations.Expose
 import com.google.gson.annotations.SerializedName
 
+@Entity(tableName = "recipe")
 data class Recipe(
-    @SerializedName("idMeal")var recipeID : String = "",
-    @SerializedName("strMeal")var name : String = "",
-    @SerializedName("strCategory")var category : String = "",
-    @SerializedName("strArea")var cuisine : String = "",
-    @SerializedName("strInstructions")var instructions : String = "",
-    @SerializedName("strMealThumb")var imageURL : String = "",
-    @SerializedName("strYoutube")var youtubeURL : String = "",
-    @Expose var ingredients : MutableMap<String, String> = LinkedHashMap(),
-    @Transient var fireStoreID: String = "",
-    ) {
+    @PrimaryKey @ColumnInfo(name = "id") @SerializedName("idMeal") var recipeID: String = "",
+    @SerializedName("strMeal") var name: String = "",
+    @SerializedName("strCategory") var category: String = "",
+    @SerializedName("strArea") var cuisine: String = "",
+    @SerializedName("strInstructions") var instructions: String = "",
+    @ColumnInfo(name = "image_url") @SerializedName("strMealThumb") var imageURL: String = "",
+    @ColumnInfo(name = "youtube_url") @SerializedName("strYoutube") var youtubeURL: String = "",
+    @Expose var ingredients: MutableMap<String, String> = LinkedHashMap(),
+    @Ignore @Transient var fireStoreID: String = "",
+) {
     override fun toString(): String {
         return name
     }

app/src/main/java/com/cookit/service/KtorRecipeService.kt

@@ -1,6 +1,13 @@
 package com.cookit.service
 
+import android.app.Application
+import android.content.ContentValues.TAG
+import android.util.Log
+import androidx.room.Room
 import com.cookit.KtorClientInstance
+import com.cookit.dao.IRecipeDAO
+import com.cookit.dao.RecipeDatabase
+import com.cookit.dto.Recipe
 import com.cookit.dto.RecipeList
 import io.ktor.client.call.*
 import io.ktor.client.request.*
@@ -12,18 +19,44 @@ private val CALLS = mapOf("allRecipes" to "9973533/search.php?s=")
 
 interface IRecipeService {
     suspend fun fetchRecipes(call: String = "allRecipes"): RecipeList?
+    fun getRecipeDAO(): IRecipeDAO
 }
 
-class KtorRecipeService : IRecipeService {
+class KtorRecipeService(val application: Application) : IRecipeService {
+    lateinit var db: RecipeDatabase
+
     override suspend fun fetchRecipes(call: String): RecipeList? {
         return withContext(Dispatchers.IO) {
             val response = KtorClientInstance.ktorInstance?.get(BASE_URL + CALLS[call])
                 ?: throw Exception("Error!, ktorClient was null for some reason!")
             if (response.status.value in 200..299) {
+                updateRecipes(response.body())
                 return@withContext response.body()
             } else {
                 throw Exception("Failed to get recipes. Server Response: ${response.status.value}")
             }
         }
     }
+
+    private fun updateRecipes(recipeList: RecipeList?) {
+        try {
+            val recipes = recipeList?.recipes ?: arrayListOf()
+            recipes.let {
+                val recipeDao = getRecipeDAO()
+                recipeDao.insertAll(recipes)
+            }
+        } catch (e: Exception) {
+            Log.e(TAG, "Error saving recipes")
+        }
+    }
+
+    override fun getRecipeDAO(): IRecipeDAO {
+        if (!this::db.isInitialized) {
+            db = Room.databaseBuilder(
+                application,
+                RecipeDatabase::class.java, "recipe-db"
+            ).build()
+        }
+        return db.recipeDao()
+    }
 }

app/src/main/java/com/cookit/service/StringMapConverter.kt

@@ -0,0 +1,27 @@
+package com.cookit.service
+
+import androidx.room.TypeConverter
+import java.util.*
+
+class StringMapConverter {
+    @TypeConverter
+    fun fromStringMap(value: Map<String, String>): String {
+        val sortedMap = TreeMap(value)
+        return sortedMap.keys.joinToString(separator = ",").plus("<divider>")
+            .plus(sortedMap.values.joinToString(separator = ","))
+    }
+
+    @TypeConverter
+    fun toStringMap(value: String): Map<String, String> {
+        return value.split("<divider>").run {
+            val keys = getOrNull(0)?.split(",")?.map { it }
+            val values = getOrNull(1)?.split(",")?.map { it }
+
+            val res = hashMapOf<String, String>()
+            keys?.forEachIndexed { index, s ->
+                res[s] = values?.getOrNull(index) ?: ""
+            }
+            res
+        }
+    }
+}

app/src/test/java/com/cookit/RecipeIntegrationTest.kt

@@ -1,17 +1,30 @@
 package com.cookit
 
+import android.app.Application
 import androidx.arch.core.executor.testing.InstantTaskExecutorRule
 import com.cookit.dto.RecipeList
 import com.cookit.service.KtorRecipeService
 import junit.framework.Assert.assertNotNull
 import junit.framework.Assert.assertTrue
 import kotlinx.coroutines.test.runTest
+import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
 import org.junit.rules.TestRule
+import org.mockito.Mock
+import org.mockito.MockitoAnnotations
+
 
 class RecipeIntegrationTest {
 
+    @Mock
+    private lateinit var application: Application
+
+    @Before
+    fun init() {
+        MockitoAnnotations.initMocks(this)
+    }
+
     @get:Rule
     var rule: TestRule = InstantTaskExecutorRule()
 
@@ -35,7 +48,7 @@ class RecipeIntegrationTest {
 
 
     private fun givenRecipeServiceIsInitialized() {
-        recipeService = KtorRecipeService()
+        recipeService = KtorRecipeService(application)
     }
 
     private suspend fun whenRecipeDataIsParsed() {

build.gradle

@@ -4,6 +4,7 @@ buildscript {
         compose_version = '1.0.1'
         koin_version = "3.1.5"
         ktor_version = "2.0.1"
+        room_version = "2.4.2"
     }
     repositories {
         google()