[Draft][flutter_appauth][flutter_appauth_platform_interface] Add platform method to process callbacks which where not received nativly

flutter_appauth/ios/Classes/FlutterAppAuth.h

@@ -21,6 +21,7 @@ static NSString *const AUTHORIZE_METHOD = @"authorize";
 static NSString *const AUTHORIZE_AND_EXCHANGE_CODE_METHOD = @"authorizeAndExchangeCode";
 static NSString *const TOKEN_METHOD = @"token";
 static NSString *const END_SESSION_METHOD = @"endSession";
+static NSString *const PROCESS_CALLBACK = @"processCallback";
 static NSString *const AUTHORIZE_ERROR_CODE = @"authorize_failed";
 static NSString *const AUTHORIZE_AND_EXCHANGE_CODE_ERROR_CODE = @"authorize_and_exchange_code_failed";
 static NSString *const DISCOVERY_ERROR_CODE = @"discovery_failed";

flutter_appauth/ios/Classes/FlutterAppauthPlugin.m

@@ -123,6 +123,8 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
         [self handleTokenMethodCall:[call arguments] result:result];
     } else if([END_SESSION_METHOD isEqualToString:call.method]) {
         [self handleEndSessionMethodCall:[call arguments] result:result];
+    } else if([PROCESS_CALLBACK isEqualToString:call.method]) {
+        [self processCallback:[call arguments] result:result];
     } else {
         result(FlutterMethodNotImplemented);
     }
@@ -260,6 +262,12 @@ -(void)handleEndSessionMethodCall:(NSDictionary*)arguments result:(FlutterResult
     }
 }
 
+- (void) processCallback:(NSDictionary*)arguments result:(FlutterResult)result {
+  NSString *url = [arguments valueForKey:@"url"];
+  [_currentAuthorizationFlow resumeExternalUserAgentFlowWithURL:url];
+  _currentAuthorizationFlow = nil;
+}
+
 - (void)performTokenRequest:(OIDServiceConfiguration *)serviceConfiguration requestParameters:(TokenRequestParameters *)requestParameters result:(FlutterResult)result {
     OIDTokenRequest *tokenRequest =
     [[OIDTokenRequest alloc] initWithConfiguration:serviceConfiguration

flutter_appauth/lib/src/flutter_appauth.dart

@@ -4,8 +4,7 @@ class FlutterAppAuth {
   const FlutterAppAuth();
 
   /// Convenience method for authorizing and then exchanges code
-  Future<AuthorizationTokenResponse?> authorizeAndExchangeCode(
-      AuthorizationTokenRequest request) {
+  Future<AuthorizationTokenResponse?> authorizeAndExchangeCode(AuthorizationTokenRequest request) {
     return FlutterAppAuthPlatform.instance.authorizeAndExchangeCode(request);
   }
 
@@ -22,4 +21,8 @@ class FlutterAppAuth {
   Future<EndSessionResponse?> endSession(EndSessionRequest request) {
     return FlutterAppAuthPlatform.instance.endSession(request);
   }
+
+  Future<void> processCallback(String url) {
+    return FlutterAppAuthPlatform.instance.processCallback(url);
+  }
 }

flutter_appauth_platform_interface/lib/src/flutter_appauth_platform.dart

@@ -31,10 +31,8 @@ abstract class FlutterAppAuthPlatform extends PlatformInterface {
   }
 
   /// Convenience method for authorizing and then exchanges the authorization grant code.
-  Future<AuthorizationTokenResponse?> authorizeAndExchangeCode(
-      AuthorizationTokenRequest request) {
-    throw UnimplementedError(
-        'authorizeAndExchangeCode() has not been implemented');
+  Future<AuthorizationTokenResponse?> authorizeAndExchangeCode(AuthorizationTokenRequest request) {
+    throw UnimplementedError('authorizeAndExchangeCode() has not been implemented');
   }
 
   /// Sends an authorization request.
@@ -50,4 +48,8 @@ abstract class FlutterAppAuthPlatform extends PlatformInterface {
   Future<EndSessionResponse?> endSession(EndSessionRequest request) {
     throw UnimplementedError('endSession() has not been implemented');
   }
+
+  Future<void> processCallback(String url) {
+    throw UnimplementedError('processCallback() has not been implemented');
+  }
 }

flutter_appauth_platform_interface/lib/src/method_channel_flutter_appauth.dart

@@ -11,31 +11,26 @@ import 'method_channel_mappers.dart';
 import 'token_request.dart';
 import 'token_response.dart';
 
-const MethodChannel _channel =
-    MethodChannel('crossingthestreams.io/flutter_appauth');
+const MethodChannel _channel = MethodChannel('crossingthestreams.io/flutter_appauth');
 
 class MethodChannelFlutterAppAuth extends FlutterAppAuthPlatform {
   @override
   Future<AuthorizationResponse?> authorize(AuthorizationRequest request) async {
-    final Map<dynamic, dynamic>? result =
-        await _channel.invokeMethod('authorize', request.toMap());
+    final Map<dynamic, dynamic>? result = await _channel.invokeMethod('authorize', request.toMap());
     if (result == null) {
       return null;
     }
     return AuthorizationResponse(
       authorizationCode: result['authorizationCode'],
       codeVerifier: result['codeVerifier'],
       nonce: result['nonce'],
-      authorizationAdditionalParameters:
-          result['authorizationAdditionalParameters']?.cast<String, dynamic>(),
+      authorizationAdditionalParameters: result['authorizationAdditionalParameters']?.cast<String, dynamic>(),
     );
   }
 
   @override
-  Future<AuthorizationTokenResponse?> authorizeAndExchangeCode(
-      AuthorizationTokenRequest request) async {
-    final Map<dynamic, dynamic>? result = await _channel.invokeMethod(
-        'authorizeAndExchangeCode', request.toMap());
+  Future<AuthorizationTokenResponse?> authorizeAndExchangeCode(AuthorizationTokenRequest request) async {
+    final Map<dynamic, dynamic>? result = await _channel.invokeMethod('authorizeAndExchangeCode', request.toMap());
     if (result == null) {
       return null;
     }
@@ -44,8 +39,7 @@ class MethodChannelFlutterAppAuth extends FlutterAppAuthPlatform {
         result['refreshToken'],
         result['accessTokenExpirationTime'] == null
             ? null
-            : DateTime.fromMillisecondsSinceEpoch(
-                result['accessTokenExpirationTime'].toInt()),
+            : DateTime.fromMillisecondsSinceEpoch(result['accessTokenExpirationTime'].toInt()),
         result['idToken'],
         result['tokenType'],
         result['scopes']?.cast<String>(),
@@ -55,8 +49,7 @@ class MethodChannelFlutterAppAuth extends FlutterAppAuthPlatform {
 
   @override
   Future<TokenResponse?> token(TokenRequest request) async {
-    final Map<dynamic, dynamic>? result =
-        await _channel.invokeMethod('token', request.toMap());
+    final Map<dynamic, dynamic>? result = await _channel.invokeMethod('token', request.toMap());
     if (result == null) {
       return null;
     }
@@ -65,8 +58,7 @@ class MethodChannelFlutterAppAuth extends FlutterAppAuthPlatform {
         result['refreshToken'],
         result['accessTokenExpirationTime'] == null
             ? null
-            : DateTime.fromMillisecondsSinceEpoch(
-                result['accessTokenExpirationTime'].toInt()),
+            : DateTime.fromMillisecondsSinceEpoch(result['accessTokenExpirationTime'].toInt()),
         result['idToken'],
         result['tokenType'],
         result['scopes']?.cast<String>(),
@@ -75,11 +67,15 @@ class MethodChannelFlutterAppAuth extends FlutterAppAuthPlatform {
 
   @override
   Future<EndSessionResponse?> endSession(EndSessionRequest request) async {
-    final Map<dynamic, dynamic>? result =
-        await _channel.invokeMethod('endSession', request.toMap());
+    final Map<dynamic, dynamic>? result = await _channel.invokeMethod('endSession', request.toMap());
     if (result == null) {
       return null;
     }
     return EndSessionResponse(result['state']);
   }
+
+  @override
+  Future<void> processCallback(String url) async {
+    await _channel.invokeMethod('processCallback', {"url": url});
+  }
 }