Merge pull request #13 from SimCoderYoutube/lesson_13/retweet_a_post_…

…with_firebase_firestore

[Add] retweet action

backend/functions/index.js

@@ -26,3 +26,26 @@ exports.deleteLike = functions.firestore.document('/posts/{postId}/likes/{userId
  likesCount: admin.firestore.FieldValue.increment(-1)
  })
 })
+
+
+exports.addRetweet = functions.firestore.document('/posts/{postId}/retweets/{userId}')
+.onCreate((snap, context) => {
+ return db
+ .collection("posts")
+ .doc(context.params.postId)
+ .update(
+ {
+ retweetsCount: admin.firestore.FieldValue.increment(1)
+ })
+})
+
+exports.deleteRetweet = functions.firestore.document('/posts/{postId}/retweets/{userId}')
+.onDelete((snap, context) => {
+ return db
+ .collection("posts")
+ .doc(context.params.postId)
+ .update(
+ {
+ retweetsCount: admin.firestore.FieldValue.increment(-1)
+ })
+})

frontend/lib/models/post.dart

@@ -5,8 +5,19 @@ class PostModel {
  final String creator;
  final String text;
  final Timestamp timestamp;
+ final String originalId;
+ final bool retweet;
+
  int likesCount;
+ int retweetsCount;
 
  PostModel(
- {this.id, this.creator, this.text, this.timestamp, this.likesCount});
+ {this.id,
+ this.creator,
+ this.text,
+ this.timestamp,
+ this.likesCount,
+ this.retweetsCount,
+ this.originalId,
+ this.retweet});
 }

frontend/lib/screens/main/posts/Item.dart

@@ -0,0 +1,104 @@
+import 'package:flutter/material.dart';
+import 'package:twitter/models/post.dart';
+import 'package:twitter/models/user.dart';
+import 'package:twitter/services/posts.dart';
+
+class ItemPost extends StatefulWidget {
+ final PostModel post;
+ final AsyncSnapshot<UserModel> snapshotUser;
+ final AsyncSnapshot<bool> snapshotLike;
+ final AsyncSnapshot<bool> snapshotRetweet;
+ final bool retweet;
+
+ ItemPost(this.post, this.snapshotUser, this.snapshotLike,
+ this.snapshotRetweet, this.retweet,
+ {Key key})
+ : super(key: key);
+
+ @override
+ _ItemPostState createState() => _ItemPostState();
+}
+
+class _ItemPostState extends State<ItemPost> {
+ PostService _postService = PostService();
+ @override
+ Widget build(BuildContext context) {
+ return ListTile(
+ title: Padding(
+ padding: EdgeInsets.fromLTRB(0, 15, 0, 15),
+ child: Column(
+ crossAxisAlignment: CrossAxisAlignment.start,
+ children: [
+ if (widget.snapshotRetweet.data || widget.retweet)
+ Text("Retweet"),
+ SizedBox(height: 20),
+ Row(
+ children: [
+ widget.snapshotUser.data.profileImageUrl != ''
+ ? CircleAvatar(
+ radius: 20,
+ backgroundImage: NetworkImage(
+ widget.snapshotUser.data.profileImageUrl))
+ : Icon(Icons.person, size: 40),
+ SizedBox(width: 10),
+ Text(widget.snapshotUser.data.name)
+ ],
+ ),
+ ],
+ )),
+ subtitle: Column(
+ crossAxisAlignment: CrossAxisAlignment.start,
+ children: [
+ Padding(
+ padding: EdgeInsets.fromLTRB(0, 15, 0, 15),
+ child: Column(
+ crossAxisAlignment: CrossAxisAlignment.start,
+ children: [
+ Text(widget.post.text),
+ SizedBox(height: 20),
+ Text(widget.post.timestamp.toDate().toString()),
+ SizedBox(height: 20),
+ Row(
+ mainAxisAlignment: MainAxisAlignment.spaceAround,
+ children: [
+ Row(
+ children: [
+ IconButton(
+ icon: new Icon(
+ widget.snapshotRetweet.data
+ ? Icons.cancel
+ : Icons.repeat,
+ color: Colors.blue,
+ size: 30.0),
+ onPressed: () => _postService.retweet(
+ widget.post, widget.snapshotRetweet.data)),
+ Text(widget.post.retweetsCount.toString())
+ ],
+ ),
+ Row(
+ children: [
+ IconButton(
+ icon: new Icon(
+ widget.snapshotLike.data
+ ? Icons.favorite
+ : Icons.favorite_border,
+ color: Colors.blue,
+ size: 30.0),
+ onPressed: () {
+ _postService.likePost(
+ widget.post, widget.snapshotLike.data);
+ }),
+ Text(widget.post.likesCount.toString())
+ ],
+ )
+ ],
+ )
+ ],
+ ),
+ ),
+ Divider(),
+ ],
+ ),
+ );
+ }
+}

frontend/lib/screens/main/posts/list.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import 'package:twitter/models/post.dart';
 import 'package:twitter/models/user.dart';
+import 'package:twitter/screens/main/posts/Item.dart';
 import 'package:twitter/services/posts.dart';
 import 'package:twitter/services/user.dart';
 
@@ -23,73 +24,51 @@ class _ListPostsState extends State<ListPosts> {
  itemCount: posts.length,
  itemBuilder: (context, index) {
  final post = posts[index];
- return StreamBuilder(
- stream: _userService.getUserInfo(post.creator),
- builder:
- (BuildContext context, AsyncSnapshot<UserModel> snapshotUser) {
- if (!snapshotUser.hasData) {
- return Center(child: CircularProgressIndicator());
- }
-
- //stream builder to get user like
- return StreamBuilder(
- stream: _postService.getCurrentUserLike(post),
- builder:
- (BuildContext context, AsyncSnapshot<bool> snapshotLike) {
- if (!snapshotLike.hasData) {
- return Center(child: CircularProgressIndicator());
- }
-
- return ListTile(
- title: Padding(
- padding: EdgeInsets.fromLTRB(0, 15, 0, 15),
- child: Row(
- children: [
- snapshotUser.data.profileImageUrl != ''
- ? CircleAvatar(
- radius: 20,
- backgroundImage: NetworkImage(
- snapshotUser.data.profileImageUrl))
- : Icon(Icons.person, size: 40),
- SizedBox(width: 10),
- Text(snapshotUser.data.name)
- ],
- ),
- ),
- subtitle: Column(
- crossAxisAlignment: CrossAxisAlignment.start,
- children: [
- Padding(
- padding: EdgeInsets.fromLTRB(0, 15, 0, 15),
- child: Column(
- crossAxisAlignment: CrossAxisAlignment.start,
- children: [
- Text(post.text),
- SizedBox(height: 20),
- Text(post.timestamp.toDate().toString()),
- SizedBox(height: 20),
- IconButton(
- icon: new Icon(
- snapshotLike.data
- ? Icons.favorite
- : Icons.favorite_border,
- color: Colors.blue,
- size: 30.0),
- onPressed: () {
- _postService.likePost(
- post, snapshotLike.data);
- }),
- Text(post.likesCount.toString())
- ],
- ),
- ),
- Divider(),
- ],
- ),
- );
- });
- });
+ if (post.retweet) {
+ return FutureBuilder(
+ future: _postService.getPostById(post.originalId),
+ builder: (BuildContext context,
+ AsyncSnapshot<PostModel> snapshotPost) {
+ if (!snapshotPost.hasData) {
+ return Center(child: CircularProgressIndicator());
+ }
+ return mainPost(snapshotPost.data, true);
+ });
+ }
+ return mainPost(post, false);
  },
  );
  }
+
+ StreamBuilder<UserModel> mainPost(PostModel post, bool retweet) {
+ return StreamBuilder(
+ stream: _userService.getUserInfo(post.creator),
+ builder: (BuildContext context, AsyncSnapshot<UserModel> snapshotUser) {
+ if (!snapshotUser.hasData) {
+ return Center(child: CircularProgressIndicator());
+ }
+
+ //stream builder to get user like
+ return StreamBuilder(
+ stream: _postService.getCurrentUserLike(post),
+ builder:
+ (BuildContext context, AsyncSnapshot<bool> snapshotLike) {
+ if (!snapshotLike.hasData) {
+ return Center(child: CircularProgressIndicator());
+ } //stream builder to get user like
+
+ return StreamBuilder(
+ stream: _postService.getCurrentUserRetweet(post),
+ builder: (BuildContext context,
+ AsyncSnapshot<bool> snapshotRetweet) {
+ if (!snapshotLike.hasData) {
+ return Center(child: CircularProgressIndicator());
+ }
+
+ return ItemPost(post, snapshotUser, snapshotLike,
+ snapshotRetweet, retweet);
+ });
+ });
+ });
+ }
 }

frontend/lib/services/posts.dart

@@ -15,10 +15,28 @@ class PostService {
  creator: doc.data()['creator'] ?? '',
  timestamp: doc.data()['timestamp'] ?? 0,
  likesCount: doc.data()['likesCount'] ?? 0,
+ retweetsCount: doc.data()['retweetsCount'] ?? 0,
+ retweet: doc.data()['retweet'] ?? false,
+ originalId: doc.data()['originalId'] ?? null,
  );
  }).toList();
  }
 
+ PostModel _postFromSnapshot(DocumentSnapshot snapshot) {
+ return snapshot.exists
+ ? PostModel(
+ id: snapshot.id,
+ text: snapshot.data()['text'] ?? '',
+ creator: snapshot.data()['creator'] ?? '',
+ timestamp: snapshot.data()['timestamp'] ?? 0,
+ likesCount: snapshot.data()['likesCount'] ?? 0,
+ retweetsCount: snapshot.data()['retweetsCount'] ?? 0,
+ retweet: snapshot.data()['retweet'] ?? false,
+ originalId: snapshot.data()['originalId'] ?? null,
+ )
+ : null;
+ }
+
  Future savePost(text) async {
  await FirebaseFirestore.instance.collection("posts").add({
  'text': text,
@@ -40,7 +58,6 @@ class PostService {
  }
  if (!current) {
  post.likesCount = post.likesCount + 1;
-
  await FirebaseFirestore.instance
  .collection("posts")
  .doc(post.id)
@@ -50,6 +67,49 @@ class PostService {
  }
  }
 
+ Future retweet(PostModel post, bool current) async {
+ if (current) {
+ post.retweetsCount = post.retweetsCount - 1;
+ await FirebaseFirestore.instance
+ .collection("posts")
+ .doc(post.id)
+ .collection("retweets")
+ .doc(FirebaseAuth.instance.currentUser.uid)
+ .delete();
+
+ await FirebaseFirestore.instance
+ .collection("posts")
+ .where("originalId", isEqualTo: post.id)
+ .where("creator", isEqualTo: FirebaseAuth.instance.currentUser.uid)
+ .get()
+ .then((value) {
+ if (value.docs.length == 0) {
+ return;
+ }
+ FirebaseFirestore.instance
+ .collection("posts")
+ .doc(value.docs[0].id)
+ .delete();
+ });
+ // Todo remove the retweet
+ return;
+ }
+ post.retweetsCount = post.retweetsCount + 1;
+ await FirebaseFirestore.instance
+ .collection("posts")
+ .doc(post.id)
+ .collection("retweets")
+ .doc(FirebaseAuth.instance.currentUser.uid)
+ .set({});
+
+ await FirebaseFirestore.instance.collection("posts").add({
+ 'creator': FirebaseAuth.instance.currentUser.uid,
+ 'timestamp': FieldValue.serverTimestamp(),
+ 'retweet': true,
+ 'originalId': post.id
+ });
+ }
+
  Stream<bool> getCurrentUserLike(PostModel post) {
  return FirebaseFirestore.instance
  .collection("posts")
@@ -62,6 +122,25 @@ class PostService {
  });
  }
 
+ Stream<bool> getCurrentUserRetweet(PostModel post) {
+ return FirebaseFirestore.instance
+ .collection("posts")
+ .doc(post.id)
+ .collection("retweets")
+ .doc(FirebaseAuth.instance.currentUser.uid)
+ .snapshots()
+ .map((snapshot) {
+ return snapshot.exists;
+ });
+ }
+
+ Future<PostModel> getPostById(String id) async {
+ DocumentSnapshot postSnap =
+ await FirebaseFirestore.instance.collection("posts").doc(id).get();
+
+ return _postFromSnapshot(postSnap);
+ }
+
  Stream<List<PostModel>> getPostsByUser(uid) {
  return FirebaseFirestore.instance
  .collection("posts")