[webchannel] Add Objective-C client implementation

webchannel/objc/WebChannel.podspec

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+Pod::Spec.new do |s|
+  s.name             = 'WebChannel'
+  s.version          = '0.1.0'
+  s.summary          = 'Objective-C client for WebChannel'
+  s.description      = <<-DESC
+Objective-C client implementation for WebChannel, providing robust bidirectional
+communication over HTTP.
+                       DESC
+  s.homepage         = 'https://github.com/google/net_http'
+  s.license          = { :type => 'Apache License, Version 2.0', :file => '../../LICENSE' }
+  s.author           = { 'Google LLC' => 'webchannel-dev@google.com' }
+  s.source           = { :git => 'https://github.com/google/net_http.git', :tag => s.version.to_s }
+
+  s.ios.deployment_target = '12.0'
+  s.osx.deployment_target = '10.15'
+
+  s.source_files = 'imported_src/**/*.{h,m}'
+  s.exclude_files = 'imported_src/Tests/**/*.{h,m}'
+
+  s.dependency 'GTMSessionFetcher', '~> 3.0'
+
+  s.test_spec 'Tests' do |test_spec|
+    test_spec.source_files = 'imported_src/Tests/**/*.{h,m}'
+    test_spec.dependency 'OCMock', '~> 3.0'
+  end
+end

webchannel/objc/imported_src/Support/WCDefaultHTTPRequest.h

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+#import <Foundation/Foundation.h>
+
+#import "WCHTTPRequest.h"
+
+@class GTMSessionFetcherService;
+
+@interface WCDefaultHTTPRequest : NSObject <WCHTTPRequest>
+
+- (instancetype)initWithStateChangeHandler:(id<WCRequestStateChangedHandler>)handler
+                             dispatchQueue:(dispatch_queue_t)dispatchQueue
+                            fetcherService:(nonnull GTMSessionFetcherService *)fetcherService;
+
+@end

webchannel/objc/imported_src/Support/WCDefaultHTTPRequest.m

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+#import "WCDefaultHTTPRequest.h"
+
+#import "WCHTTPRequest.h"
+#import <GTMSessionFetcher/GTMSessionFetcher.h>
+#import <GTMSessionFetcher/GTMSessionFetcherService.h>
+
+@implementation WCDefaultHTTPRequest {
+  // Internal queue used to handle all Webchannel logic to ensure thread safety.
+  dispatch_queue_t _dispatchQueue;
+  GTMSessionFetcherService *_fetcherService;
+
+  GTMSessionFetcher *_fetcher;
+  NSHTTPURLResponse *_Nullable _response;
+}
+
+@synthesize requestReadyStateChangeHandler = _requestReadyStateChangeHandler;
+@synthesize requestReadyState = _requestReadyState;
+@synthesize requestErrorCode = _requestErrorCode;
+
+- (instancetype)initWithStateChangeHandler:(id<WCRequestStateChangedHandler>)handler
+                             dispatchQueue:(dispatch_queue_t)dispatchQueue
+                            fetcherService:(nonnull GTMSessionFetcherService *)fetcherService {
+  self = [super init];
+  if (self) {
+    _requestReadyStateChangeHandler = handler;
+    _dispatchQueue = dispatchQueue;
+    _fetcherService = fetcherService;
+    _requestErrorCode = WCRequestErrorCodeNoError;
+  }
+  return self;
+}
+
+- (NSString *)responseHeaderForName:(NSString *)name {
+  return [_response valueForHTTPHeaderField:name];
+}
+
+- (int)status {
+  return (int)_fetcher.statusCode;
+}
+
+#pragma mark - WCHTTPRequest
+
+- (void)sendPOST:(NSURL *)URL
+        withData:(NSData *)POSTData
+     withHeaders:(NSDictionary<NSString *, NSString *> *)headers
+         timeout:(NSTimeInterval)timeout {
+  NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:URL];
+  request.HTTPMethod = @"POST";
+  request.timeoutInterval = timeout;
+  request.HTTPBody = POSTData;
+  request.allHTTPHeaderFields = headers;
+
+  [self beginFetchWithRequest:request];
+}
+
+- (void)sendGET:(NSURL *)URL
+    withHeaders:(NSDictionary<NSString *, NSString *> *)headers
+        timeout:(NSTimeInterval)timeout {
+  NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:URL];
+  request.HTTPMethod = @"GET";
+  request.timeoutInterval = timeout;
+  request.allHTTPHeaderFields = headers;
+
+  [self beginFetchWithRequest:request];
+}
+
+- (void)abort {
+  [_fetcher stopFetching];
+}
+
+- (void)beginFetchWithRequest:(NSURLRequest *)request {
+  _fetcher = [_fetcherService fetcherWithRequest:request];
+  _fetcher.callbackQueue = _dispatchQueue;
+#if DEBUG
+  _fetcher.allowLocalhostRequest = YES;
+#endif
+
+  __weak WCDefaultHTTPRequest *weakSelf = self;
+  _fetcher.didReceiveResponseBlock =
+      ^(NSURLResponse *response,
+        GTMSessionFetcherDidReceiveResponseDispositionBlock completionHandler) {
+        WCDefaultHTTPRequest *strongSelf = weakSelf;
+        if (strongSelf) {
+          strongSelf->_response = (NSHTTPURLResponse *)response;
+          strongSelf->_requestReadyState = WCRequestReadyStateLoaded;
+          [strongSelf->_requestReadyStateChangeHandler stateChangedForRequest:strongSelf
+                                                                 responseData:NULL];
+        }
+        completionHandler(NSURLSessionResponseAllow);
+      };
+
+  _fetcher.accumulateDataBlock = ^(NSData *data) {
+    WCDefaultHTTPRequest *strongSelf = weakSelf;
+    if (strongSelf) {
+      strongSelf->_requestReadyState = WCRequestReadyStateInteractive;
+      [strongSelf->_requestReadyStateChangeHandler stateChangedForRequest:strongSelf
+                                                             responseData:data];
+    }
+  };
+
+  [_fetcher beginFetchWithCompletionHandler:^(NSData *data, NSError *error) {
+    WCDefaultHTTPRequest *strongSelf = weakSelf;
+    if (!strongSelf) {
+      return;
+    }
+    if (error) {
+      strongSelf->_requestErrorCode = [strongSelf errorCodeForError:error];
+    } else {
+      if (strongSelf->_fetcher.statusCode != 200) {
+        strongSelf->_requestErrorCode = WCRequestErrorCodeHTTPError;
+      }
+    }
+    strongSelf->_requestReadyState = WCRequestReadyStateComplete;
+    [strongSelf->_requestReadyStateChangeHandler stateChangedForRequest:strongSelf
+                                                           responseData:NULL];
+  }];
+}
+
+- (WCRequestErrorCode)errorCodeForError:(NSError *)error {
+  if ([error.domain isEqual:kGTMSessionFetcherStatusDomain]) {
+    return WCRequestErrorCodeHTTPError;
+  } else if ([error.domain isEqual:NSURLErrorDomain]) {
+    if (error.code == NSURLErrorTimedOut) {
+      return WCRequestErrorCodeTimeout;
+    } else if (error.code == NSURLErrorCancelled) {
+      return WCRequestErrorCodeAbort;
+    } else {
+      return WCRequestErrorCodeException;
+    }
+  } else {
+    return WCRequestErrorCodeException;
+  }
+}
+
+@end

webchannel/objc/imported_src/Support/WCDefaultJSONDecoder.h

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+#import <Foundation/Foundation.h>
+
+#import "WCJSONDecoder.h"
+
+@interface WCDefaultJSONDecoder : NSObject <WCJSONDecoder>
+@end

webchannel/objc/imported_src/Support/WCDefaultJSONDecoder.m

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+#import "WCDefaultJSONDecoder.h"
+
+@implementation WCDefaultJSONDecoder
+
+- (NSArray *)decodeData:(NSString *)data maxDepth:(int)maxDepth {
+  // TODO(eryu): Refactor to avoid inefficient NSData->NSString->NSData conversion.
+  // WCChannelRequest converts network response from NSData to NSString before
+  // calling its delegate's -didReceiveInput:withRequest: method. The input
+  // eventually reaches this method as NSString, which is converted back to
+  // NSData because the underlying JSON parser (NSJSONSerialization) requires
+  // NSData. This data path should be optimized to pass NSData directly to
+  // eliminate the redundant conversions.
+  NSData *encodingData = [data dataUsingEncoding:NSUTF8StringEncoding];
+  NSArray<id> *JSONArray = [NSJSONSerialization JSONObjectWithData:encodingData options:0 error:nil];
+  return JSONArray;
+}
+
+@end

webchannel/objc/imported_src/Support/WCDefaultLogger.h

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+#import <Foundation/Foundation.h>
+
+#import "WCLogger.h"
+
+extern BOOL gWCVerboseLoggingEnabled;
+
+/** Convenience macro of Debug. */
+#ifndef WCDefaultLoggerDebug
+
+#define WCDefaultLoggerDebug(...) \
+  if (gWCVerboseLoggingEnabled) { \
+    NSLog(__VA_ARGS__);           \
+  }
+
+#ifndef DEBUG
+#undef WCDefaultLoggerDebug
+#define WCDefaultLoggerDebug(...) \
+  do {                            \
+  } while (0)
+#endif
+
+#endif
+
+/** Convenience macro of Info. */
+#ifndef WCDefaultLoggerInfo
+
+#define WCDefaultLoggerInfo(...) NSLog(__VA_ARGS__);
+
+#endif
+
+/** Convenience macro of Error. */
+#ifndef WCDefaultLoggerError
+
+#define WCDefaultLoggerError(...) \
+  if (gWCVerboseLoggingEnabled) { \
+    NSLog(__VA_ARGS__);           \
+  }
+
+#endif
+
+@interface WCDefaultLogger : NSObject <WCLogger>
+@end

webchannel/objc/imported_src/Support/WCDefaultLogger.m

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+#import "WCDefaultLogger.h"
+#import "WCHTTPRequest.h"
+
+#if WC_VERBOSE_LOGGING
+BOOL gWCVerboseLoggingEnabled = YES;
+#else
+BOOL gWCVerboseLoggingEnabled = NO;
+#endif  // WC_VERBOSE_LOGGING
+
+@implementation WCDefaultLogger
+
+- (void)logInfo:(NSString *)message {
+  WCDefaultLoggerInfo(@"%@", message);
+}
+
+- (void)logDebug:(NSString *)message {
+  WCDefaultLoggerDebug(@"%@", message);
+}
+
+- (void)logWarning:(NSString *)message {
+  WCDefaultLoggerInfo(@"Warning: %@", message);
+}
+
+- (void)dumpException:(NSException *)e withMessage:(NSString *)message {
+  WCDefaultLoggerError(@"Exception:%@: %@", e.name, message);
+}
+
+- (void)logError:(NSString *)message {
+  WCDefaultLoggerError(@"%@", message);
+}
+
+- (void)logHTTPRequest:(NSString *)verb
+                   URL:(NSURL *)URL
+                    ID:(NSString *)ID
+               attempt:(int64_t)attempt
+              postData:(NSString *)postData {
+  NSString *text = [NSString stringWithFormat:@"XMLHTTP REQ (%@) [attempt %lld ]: %@ \n %@ \n %@", ID,
+                                              attempt, verb, URL.absoluteString, postData];
+  [self logDebug:text];
+}
+
+- (void)logHTTPChannelResponseMetaData:(NSString *)verb
+                                   URL:(NSURL *)URL
+                                    ID:(NSString *)ID
+                               attempt:(int64_t)attempt
+                                 state:(WCRequestReadyState)state
+                            statusCode:(int32_t)code {
+  NSString *text =
+      [NSString stringWithFormat:@"XMLHTTP RESP (%@) [attempt %lld ]: %@ \n %@ \n %@ %d", ID,
+                                 attempt, verb, URL.absoluteString,
+                                 [self formatRequestReadyStateToString:state], code];
+  [self logDebug:text];
+}
+
+- (NSString*)formatRequestReadyStateToString:(WCRequestReadyState)state {
+    NSString *result = nil;
+    switch(state) {
+        case WCRequestReadyStateUninitialized:
+            result = @"RequestReadyState Uninitialized";
+            break;
+        case WCRequestReadyStateLoaded:
+            result = @"WCRequestReadyState Loaded";
+            break;
+        case WCRequestReadyStateInteractive:
+            result = @"WCRequestReadyState Interactive";
+            break;
+        case WCRequestReadyStateComplete:
+            result = @"RequestReadyState Complete";
+            break;
+        default:
+            result = @"Unexpected state";
+    }
+    return result;
+}
+
+- (void)logHTTPChannelResponseText:(NSString *)responseText
+                                ID:(NSString *)ID
+                              desc:(NSString *)desc {
+  NSString *text = [NSString stringWithFormat:@"XMLHTTP RESP (%@): %@ %@", ID, responseText, desc];
+  [self logDebug:text];
+}
+
+@end

webchannel/objc/imported_src/Support/WCDefaultURLEncoder.h

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+#import <Foundation/Foundation.h>
+
+#import "WCURLEncoder.h"
+
+@interface WCDefaultURLEncoder : NSObject <WCURLEncoder>
+@end

webchannel/objc/imported_src/Support/WCDefaultURLEncoder.m

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+#import "WCDefaultURLEncoder.h"
+
+@implementation WCDefaultURLEncoder
+
+- (NSString *)encode:(NSString *)data {
+  return [data
+      stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet alphanumericCharacterSet]];
+}
+
+@end

webchannel/objc/imported_src/Support/WCFakeHTTPRequest.h

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+#import <Foundation/Foundation.h>
+
+#import "WCHTTPRequest.h"
+
+@interface WCFakeHTTPRequest : NSObject <WCHTTPRequest>
+
+@end

webchannel/objc/imported_src/Support/WCFakeHTTPRequest.m

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+#import "WCFakeHTTPRequest.h"
+
+#import "WCHTTPRequest.h"
+
+@implementation WCFakeHTTPRequest
+
+@synthesize requestReadyStateChangeHandler = _requestReadyStateChangeHandler;
+@synthesize requestReadyState = _requestReadyState;
+@synthesize requestErrorCode = _requestErrorCode;
+
+- (NSString *)responseHeaderForName:(NSString *)name {
+  return @"";
+}
+
+- (int)status {
+  return 200;
+}
+
+- (void)sendPOST:(NSURL *)URL
+        withData:(nullable NSData *)postData
+     withHeaders:(nullable NSDictionary<NSString *, NSString *> *)headers
+         timeout:(NSTimeInterval)timeout{
+  [_requestReadyStateChangeHandler stateChangedForRequest:self responseData:nil];
+}
+
+- (void)sendGET:(NSURL *)URL withHeaders:(nullable NSDictionary<NSString *, NSString *> *)headers timeout:(NSTimeInterval)timeout {
+  [_requestReadyStateChangeHandler stateChangedForRequest:self responseData:nil];
+}
+
+- (void)abort {
+}
+
+@end