✨(feat) Add fcm notification on tweet user tag.

1.✨A notification will send to user if someone tag him in a tweet.
2.After tapping on notification from system notification tray, you will redirect to user profile who tagged you.
3.:bulb: (doc) Documenting source code

.gitignore

@@ -38,6 +38,7 @@
 **/android/local.properties
 **/android/**/GeneratedPluginRegistrant.java
 **/android/app/google-services.json
+**/android/app/key.jks
 
 # iOS/XCode related
 **/ios/**/*.mode1v3

CHANGELOG.md

@@ -3,6 +3,9 @@
 * Three tabs are added to filter tweet and commnet tweet and tweet with media on profile page.
 * User profile pic view added to view profile picture of any user.
 * User can tag other users in tweet, comment and in retweet.
+* A notification will send to you if someone tag you in a tweet.
+* After tapping on notification from system notification tray, you will redirect to user profile who tagged you.
+* You can check the tweet on his profile.
 
 ## [1.0.5] - 15 Apr 2020
 

lib/helper/enum.dart

@@ -25,4 +25,5 @@ enum NotificationType{
   Reply,
   Retweet,
   Follow,
+  Mention
 }

lib/page/feed/composeTweet/composeTweet.dart

@@ -79,6 +79,7 @@ class _ComposeTweetReplyPageState extends State<ComposeTweetPage> {
     });
   }
 
+  /// Submit tweet to save in firebase database
   void _submitButton() async {
     if (_textEditingController.text == null ||
         _textEditingController.text.isEmpty ||
@@ -89,30 +90,65 @@ class _ComposeTweetReplyPageState extends State<ComposeTweetPage> {
     kScreenloader.showLoader(context);
 
     FeedModel tweetModel = createTweetModel();
+
+    /// If tweet contain image
+    /// First image is uploaded on firebase storage
+    /// After sucessfull image upload to firebase storage it returns image path
+    /// Add this image path to tweet model and save to firebase database
     if (_image != null) {
       await state.uploadFile(_image).then((imagePath) {
         if (imagePath != null) {
           tweetModel.imagePath = imagePath;
+
+          /// If type of tweet is new tweet
           if (widget.isTweet) {
             state.createTweet(tweetModel);
-          } else if (widget.isRetweet) {
+          }
+
+          /// If type of tweet is  retweet
+          else if (widget.isRetweet) {
             state.createReTweet(tweetModel);
-          } else {
+          }
+
+          /// If type of tweet is new comment tweet
+          else {
             state.addcommentToPost(tweetModel);
           }
         }
       });
-    } else {
+    }
+
+    /// If tweet did not contain image
+    else {
+      /// If type of tweet is new tweet
       if (widget.isTweet) {
         state.createTweet(tweetModel);
-      } else if (widget.isRetweet) {
+      }
+
+      /// If type of tweet is  retweet
+      else if (widget.isRetweet) {
         state.createReTweet(tweetModel);
-      } else {
+      }
+
+      /// If type of tweet is new comment tweet
+      else {
         state.addcommentToPost(tweetModel);
       }
     }
-    kScreenloader.hideLoader();
-    Navigator.pop(context);
+
+    /// Checks for username in tweet description
+    /// If foud sends notification to all tagged user
+    /// If no user found or not compost tweet screen is closed and redirect back to home page.
+    await Provider.of<ComposeTweetState>(context, listen: false)
+        .sendNotification(
+            tweetModel, Provider.of<SearchState>(context, listen: false))
+        .then((_) {
+      /// Hide running loader on screen
+      kScreenloader.hideLoader();
+
+      /// Navigate back to home page
+      Navigator.pop(context);
+    });
   }
 
   /// Return Tweet model which is either a new Tweet , retweet model or comment model
@@ -147,7 +183,6 @@ class _ComposeTweetReplyPageState extends State<ComposeTweetPage> {
 
   @override
   Widget build(BuildContext context) {
-    // final composeState = Provider.of<ComposeTweetState>(context);
     return Scaffold(
       appBar: CustomAppBar(
         title: customTitleText(''),

lib/page/feed/composeTweet/state/composeTweetState.dart

@@ -1,16 +1,24 @@
+import 'dart:convert';
+import 'package:flutter_twitter_clone/helper/utility.dart';
+import 'package:flutter_twitter_clone/model/user.dart';
+import 'package:http/http.dart' as http;
+import 'package:firebase_remote_config/firebase_remote_config.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_twitter_clone/helper/enum.dart';
+import 'package:flutter_twitter_clone/model/feedModel.dart';
 import 'package:flutter_twitter_clone/state/searchState.dart';
 
 class ComposeTweetState extends ChangeNotifier {
   bool showUserList = false;
   bool enableSubmitButton = false;
   bool hideUserList = false;
   String description = "";
+  String serverToken;
   final usernameRegex = r'(@\w*[a-zA-Z1-9]$)';
 
-  bool _isScrollingDown  = false;
-  bool get isScrollingDown  => _isScrollingDown;
-  set setIsScrolllingDown(bool value){
+  bool _isScrollingDown = false;
+  bool get isScrollingDown => _isScrollingDown;
+  set setIsScrolllingDown(bool value) {
     _isScrollingDown = value;
     notifyListeners();
   }
@@ -79,4 +87,87 @@ class ComposeTweetState extends ChangeNotifier {
     description = '$name $username';
     return description;
   }
+
+  /// Fecth FCM server key from firebase Remote config
+  Future<Null> getFCMServerKey() async {
+    final RemoteConfig remoteConfig = await RemoteConfig.instance;
+    await remoteConfig.fetch(expiration: const Duration(hours: 5));
+    await remoteConfig.activateFetched();
+    var data = remoteConfig.getString('FcmServerKey');
+    if (data != null) {
+      serverToken = jsonDecode(data)["key"];
+    }
+  }
+
+  Future<void> sendNotification(FeedModel model, SearchState state) async {
+    final usernameRegex = r"(@\w*[a-zA-Z1-9])";
+    RegExp regExp = new RegExp(usernameRegex);
+    var status = regExp.hasMatch(description);
+    if (status) {
+      /// Fecth FCM server key from firebase Remote config
+      /// send notification to user once fcmToken is retrieved from firebase
+      getFCMServerKey().then((val) async {
+        /// Reset userlist
+        state.filterByUsername("");
+
+        /// Search all username from description
+        Iterable<Match> _matches = regExp.allMatches(description);
+        print("${_matches.length} name found in description");
+
+        /// Send notification to user one by one
+        await Future.forEach(_matches, (Match match) async {
+          var name = description.substring(match.start, match.end);
+          if (state.userlist.any((x) => x.userName == name)) {
+            /// Fetch user model from userlist
+            /// UserId, FCMtoken is needed to send notification
+            final user = state.userlist.firstWhere((x) => x.userName == name);
+            await sendNotificationToUser(model, user);
+          } else {
+            cprint("Name: $name ,", errorIn: "UserNot found");
+          }
+        });
+      });
+    }
+  }
+
+  /// Send notificatinn by using firebase notification rest api;
+  Future<void> sendNotificationToUser(FeedModel model, User user) async {
+    print("Send notification to: ${user.userName}");
+
+    /// Return from here if fcmToken is null
+    if (user.fcmToken == null) {
+      return;
+    }
+
+    /// Create notification payload
+    var body = jsonEncode(<String, dynamic>{
+      'notification': <String, dynamic>{
+        'body': model.description,
+        'title': "${model.user.displayName} metioned you in a tweet"
+      },
+      'priority': 'high',
+      'data': <String, dynamic>{
+        'click_action': 'FLUTTER_NOTIFICATION_CLICK',
+        'id': '1',
+        'status': 'done',
+        "type": NotificationType.Mention.toString(),
+        "senderId": model.user.userId,
+        "receiverId": user.userId,
+        "title": "title",
+        "body": "",
+        "tweetId": ""
+      },
+      'to': user.fcmToken
+    });
+
+    var response = await http.post(
+      'https://fcm.googleapis.com/fcm/send',
+      headers: <String, String>{
+        'Content-Type': 'application/json',
+        'Authorization': 'key=$serverToken',
+      },
+      body: body,
+    );
+    cprint(response.body.toString());
+  }
 }

lib/page/homePage.dart

@@ -22,7 +22,7 @@ class HomePage extends StatefulWidget {
 
 class _HomePageState extends State<HomePage> {
   final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();
-  final refreshIndicatorKey =new GlobalKey<RefreshIndicatorState>();
+  final refreshIndicatorKey = new GlobalKey<RefreshIndicatorState>();
   int pageIndex = 0;
   @override
   void initState() {
@@ -66,28 +66,60 @@ class _HomePageState extends State<HomePage> {
     final chatState = Provider.of<ChatState>(context, listen: false);
     final state = Provider.of<AuthState>(context, listen: false);
     chatState.databaseInit(state.userId, state.userId);
+    /// It will update fcm token in database 
+    /// fcm token is required to send firebase notification
     state.updateFCMToken();
+    /// It get fcm server key 
+    /// Server key is required to configure firebase notification
+    /// Without fcm server notification can not be sent
     chatState.getFCMServerKey();
   }
 
-  Widget _body() {
-
+  /// On app launch it checks if app is launch by tapping on notification from notification tray
+  /// If yes, it checks for  which type of notification is recieve
+  /// If notification type is `NotificationType.Message` then chat screen will open
+  /// If notification type is `NotificationType.Mention` then user profile will open who taged you in a tweet
+  ///
+  void _checkNotification() {
     final authstate = Provider.of<AuthState>(context, listen: false);
     WidgetsBinding.instance.addPostFrameCallback((_) {
       var state = Provider.of<NotificationState>(context);
+
       /// Check if user recieve chat notification from firebase
       /// Redirect to chat screen
-      if (state.notificationType == NotificationType.Message && state.notificationReciverId == authstate.userModel.userId) {
-        state.setrNotificationType = null;
+      /// `notificationSenderId` is a user id who sends you a message
+      /// `notificationReciverId` is a your user id.
+      if (state.notificationType == NotificationType.Message &&
+          state.notificationReciverId == authstate.userModel.userId) {
+        state.setNotificationType = null;
         state.getuserDetail(state.notificationSenderId).then((user) {
           cprint("Opening user chat screen");
           final chatState = Provider.of<ChatState>(context, listen: false);
           chatState.setChatUser = user;
           Navigator.pushNamed(context, '/ChatScreenPage');
         });
       }
+
+      /// Checks for user tag tweet notification
+      /// If you are mentioned in tweet then it redirect to user profile who mentioed you in a tweet
+      /// You can check that tweet on his profile timeline
+      /// `notificationSenderId` is user id who tagged you in a tweet
+      else if (state.notificationType == NotificationType.Mention &&
+          state.notificationReciverId == authstate.userModel.userId) {
+        state.setNotificationType = null;
+        Navigator.of(context)
+            .pushNamed('/ProfilePage/' + state.notificationSenderId);
+      }
     });
-    return SafeArea(child: Container(child: _getPage(Provider.of<AppState>(context).pageIndex)));
+  }
+
+  Widget _body() {
+    _checkNotification();
+    return SafeArea(
+      child: Container(
+        child: _getPage(Provider.of<AppState>(context).pageIndex),
+      ),
+    );
   }
 
   Widget _getPage(int index) {

lib/state/chats/chatState.dart

@@ -145,7 +145,6 @@ class ChatState extends AppState {
   }
 
   void onMessageSubmitted(ChatMessage message, {User myUser, User secondUser}) {
-    // print('2RhfEy0MPzdfOp9MtqtSDABau2d25kyFBK0vfDc3AkF6a8zfaudQOHw12RhfEy0MPzdfOp9MtqtSDABau2d25kyFBK0vfDc3AkF6a8zfaudQOHw1');
     try {
       if (_messageList == null || _messageList.length < 1) {
         _database

lib/state/notificationState.dart

@@ -16,9 +16,10 @@ import 'package:flutter_twitter_clone/state/appState.dart';
 class NotificationState extends AppState {
   String fcmToken;
   NotificationType _notificationType = NotificationType.NOT_DETERMINED;
-  String notificationReciverId;
+  String notificationReciverId, notificationTweetId;
+  FeedModel notificationTweetModel;
   NotificationType get notificationType => _notificationType;
-   set setrNotificationType(NotificationType type){
+   set setNotificationType(NotificationType type){
      _notificationType = type;
    }
   // FcmNotificationModel notification;
@@ -152,7 +153,7 @@ class NotificationState extends AppState {
       print("Notification Removed");
     }
   }
-
+  /// Configure notification services
   void initfirebaseService(){
     _firebaseMessaging.configure(
       onMessage: (Map<String, dynamic> message) async {
@@ -164,8 +165,15 @@ class NotificationState extends AppState {
         cprint("Notification ",event: "onLaunch");
         var data = message['data'];
         // print(message['data']);
-        notificationSenderId = data["userId"];
-        setrNotificationType = NotificationType.Message;
+        notificationSenderId = data["senderId"];
+        notificationReciverId = data["receiverId"];
+        notificationReciverId = data["receiverId"];
+         if(data["type"] == "NotificationType.Mention"){
+          setNotificationType = NotificationType.Mention;
+        }
+        else if(data["type"] == "NotificationType.Message"){
+          setNotificationType = NotificationType.Message;
+        }
         notifyListeners();
       },
       onResume: (Map<String, dynamic> message) async {
@@ -174,7 +182,12 @@ class NotificationState extends AppState {
         // print(message['data']);
         notificationSenderId = data["senderId"];
         notificationReciverId = data["receiverId"];
-        setrNotificationType = NotificationType.Message;
+         if(data["type"] == "NotificationType.Mention"){
+          setNotificationType = NotificationType.Mention;
+        }
+        else if(data["type"] == "NotificationType.Message"){
+          setNotificationType = NotificationType.Message;
+        }
         notifyListeners();
       },
     );