[Add] follow and unfollow users

frontend/lib/screens/main/profile/profile.dart

@@ -22,6 +22,10 @@ class _ProfileState extends State<Profile> {
  final String uid = ModalRoute.of(context).settings.arguments;
  return MultiProvider(
  providers: [
+ StreamProvider.value(
+ value: _userService.isFollowing(
+ FirebaseAuth.instance.currentUser.uid, uid),
+ ),
  StreamProvider.value(
  value: _postService.getPostsByUser(uid),
  ),
@@ -65,11 +69,31 @@ class _ProfileState extends State<Profile> {
  .profileImageUrl),
  )
  : Icon(Icons.person, size: 50),
- FlatButton(
- onPressed: () {
- Navigator.pushNamed(context, '/edit');
- },
- child: Text("Edit Profile"))
+ if (FirebaseAuth.instance.currentUser.uid ==
+ uid)
+ TextButton(
+ onPressed: () {
+ Navigator.pushNamed(context, '/edit');
+ },
+ child: Text("Edit Profile"))
+ else if (FirebaseAuth
+ .instance.currentUser.uid !=
+ uid &&
+ !Provider.of<bool>(context))
+ TextButton(
+ onPressed: () {
+ _userService.followUser(uid);
+ },
+ child: Text("Follow"))
+ else if (FirebaseAuth
+ .instance.currentUser.uid !=
+ uid &&
+ Provider.of<bool>(context))
+ TextButton(
+ onPressed: () {
+ _userService.unfollowUser(uid);
+ },
+ child: Text("Unfollow")),
  ]),
  Align(
  alignment: Alignment.centerLeft,

frontend/lib/services/user.dart

@@ -53,6 +53,50 @@ class UserService {
  .map(_userListFromQuerySnapshot);
  }
 
+ Stream<bool> isFollowing(uid, otherId) {
+ return FirebaseFirestore.instance
+ .collection("users")
+ .doc(uid)
+ .collection("following")
+ .doc(otherId)
+ .snapshots()
+ .map((snapshot) {
+ return snapshot.exists;
+ });
+ }
+
+ Future<void> followUser(uid) async {
+ await FirebaseFirestore.instance
+ .collection('users')
+ .doc(FirebaseAuth.instance.currentUser.uid)
+ .collection('following')
+ .doc(uid)
+ .set({});
+
+ await FirebaseFirestore.instance
+ .collection('users')
+ .doc(uid)
+ .collection('followers')
+ .doc(FirebaseAuth.instance.currentUser.uid)
+ .set({});
+ }
+
+ Future<void> unfollowUser(uid) async {
+ await FirebaseFirestore.instance
+ .collection('users')
+ .doc(FirebaseAuth.instance.currentUser.uid)
+ .collection('following')
+ .doc(uid)
+ .delete();
+
+ await FirebaseFirestore.instance
+ .collection('users')
+ .doc(uid)
+ .collection('followers')
+ .doc(FirebaseAuth.instance.currentUser.uid)
+ .delete();
+ }
+
  Future<void> updateProfile(
  File _bannerImage, File _profileImage, String name) async {
  String bannerImageUrl = '';

frontend/pubspec.lock

@@ -7,35 +7,35 @@ packages:
  name: async
  url: "https://pub.dartlang.org"
  source: hosted
- version: "2.5.0-nullsafety.1"
+ version: "2.5.0"
  boolean_selector:
  dependency: transitive
  description:
  name: boolean_selector
  url: "https://pub.dartlang.org"
  source: hosted
- version: "2.1.0-nullsafety.1"
+ version: "2.1.0"
  characters:
  dependency: transitive
  description:
  name: characters
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.1.0-nullsafety.3"
+ version: "1.1.0"
  charcode:
  dependency: transitive
  description:
  name: charcode
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.2.0-nullsafety.1"
+ version: "1.2.0"
  clock:
  dependency: transitive
  description:
  name: clock
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.1.0-nullsafety.1"
+ version: "1.1.0"
  cloud_firestore:
  dependency: "direct main"
  description:
@@ -63,7 +63,7 @@ packages:
  name: collection
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.15.0-nullsafety.3"
+ version: "1.15.0"
  convert:
  dependency: transitive
  description:
@@ -91,7 +91,7 @@ packages:
  name: fake_async
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.2.0-nullsafety.1"
+ version: "1.2.0"
  firebase_auth:
  dependency: "direct main"
  description:
@@ -218,21 +218,21 @@ packages:
  name: js
  url: "https://pub.dartlang.org"
  source: hosted
- version: "0.6.2"
+ version: "0.6.3"
  matcher:
  dependency: transitive
  description:
  name: matcher
  url: "https://pub.dartlang.org"
  source: hosted
- version: "0.12.10-nullsafety.1"
+ version: "0.12.10"
  meta:
  dependency: transitive
  description:
  name: meta
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.3.0-nullsafety.3"
+ version: "1.3.0"
  nested:
  dependency: transitive
  description:
@@ -246,7 +246,7 @@ packages:
  name: path
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.8.0-nullsafety.1"
+ version: "1.8.0"
  pedantic:
  dependency: transitive
  description:
@@ -286,56 +286,56 @@ packages:
  name: source_span
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.8.0-nullsafety.2"
+ version: "1.8.0"
  stack_trace:
  dependency: transitive
  description:
  name: stack_trace
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.10.0-nullsafety.1"
+ version: "1.10.0"
  stream_channel:
  dependency: transitive
  description:
  name: stream_channel
  url: "https://pub.dartlang.org"
  source: hosted
- version: "2.1.0-nullsafety.1"
+ version: "2.1.0"
  string_scanner:
  dependency: transitive
  description:
  name: string_scanner
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.1.0-nullsafety.1"
+ version: "1.1.0"
  term_glyph:
  dependency: transitive
  description:
  name: term_glyph
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.2.0-nullsafety.1"
+ version: "1.2.0"
  test_api:
  dependency: transitive
  description:
  name: test_api
  url: "https://pub.dartlang.org"
  source: hosted
- version: "0.2.19-nullsafety.2"
+ version: "0.2.19"
  typed_data:
  dependency: transitive
  description:
  name: typed_data
  url: "https://pub.dartlang.org"
  source: hosted
- version: "1.3.0-nullsafety.3"
+ version: "1.3.0"
  vector_math:
  dependency: transitive
  description:
  name: vector_math
  url: "https://pub.dartlang.org"
  source: hosted
- version: "2.1.0-nullsafety.3"
+ version: "2.1.0"
 sdks:
- dart: ">=2.10.0-110 <2.11.0"
- flutter: ">=1.20.0 <2.0.0"
+ dart: ">=2.12.0-0.0 <3.0.0"
+ flutter: ">=1.20.0"