Ребята, у меня есть эта страница входа с адресом электронной почты и паролем, и когда пользователь успешно вошел в систему, он выводит его на экран чата. На экране чата мне нужно получить доступ к uid пользователей, чтобы проверить, кто отправляет сообщение, но я получаю «Получатель uid» был вызван по нулевому значению ». Я использую шаблон blo c для входа с валидаторами. Как я могу исправить эту ситуацию?
class LoginScreen extends StatefulWidget {
FirebaseUser user;
@override
_LoginScreenState createState() => _LoginScreenState();
}
class _LoginScreenState extends State<LoginScreen> {
final _loginBloc = LoginBloc();
@override
void initState() {
super.initState();
_loginBloc.outState.listen((state) async {
switch (state) {
case LoginState.SUCCESS:
Navigator.of(context).pushReplacement(
MaterialPageRoute(builder: (context) => ComercialUserScreen()));
break;
case LoginState.FAIL:
showDialog(
context: context,
builder: (context) => AlertDialog(
title: Text('Erro'),
content: Text('Revise seu email e senha'),
));
break;
case LoginState.LOADING:
case LoginState.IDLE:
}
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: StreamBuilder<LoginState>(
stream: _loginBloc.outState,
initialData: LoginState.LOADING,
// ignore: missing_return
builder: (context, snapshot) {
print(snapshot.data);
switch (snapshot.data) {
case LoginState.LOADING:
return Center(
child: CircularProgressIndicator(),
);
case LoginState.FAIL:
case LoginState.SUCCESS:
case LoginState.IDLE:
return Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
InputField(
icon: Icons.person_outline,
hint: 'Usuário',
obscure: false,
stream: _loginBloc.outEmail,
onChanged: _loginBloc.changeEmail,
),
InputField(
icon: Icons.lock_outline,
hint: 'Senha',
obscure: true,
stream: _loginBloc.outEmail,
onChanged: _loginBloc.changePassword,
),
SizedBox(
height: 32,
),
StreamBuilder<bool>(
stream: _loginBloc.outSubmitValid,
builder: (context, snapshot) {
return RaisedButton(
child: Text("Entrar"),
onPressed:
snapshot.hasData ? _loginBloc.submit : null,
);
})
],
);
}
}),
);
}
}
class LoginBloc extends BlocBase with LoginValidators{
FirebaseUser _currentUser;
final _emailController = BehaviorSubject<String>();
final _passwordController = BehaviorSubject<String>();
final _stateController = BehaviorSubject<LoginState>();
Stream<String> get outEmail => _emailController.stream.transform(validateEmail);
Stream<String> get outPassword =>_passwordController.stream.transform(validatePassword);
Stream<LoginState> get outState => _stateController.stream;
Stream<bool> get outSubmitValid => Observable.combineLatest2(
outEmail, outPassword, (a, b) => true);
Function(String) get changeEmail => _emailController.sink.add;
Function(String) get changePassword => _passwordController.sink.add;
StreamSubscription _streamSubscription;
LoginBloc(){
_streamSubscription = FirebaseAuth.instance.onAuthStateChanged.listen((user) async {
if(user != null) {
if(await verifyAdmins(user)) {
_stateController.add(LoginState.SUCCESS);
} else {
FirebaseAuth.instance.signOut();
_stateController.add(LoginState.FAIL);
}
} else {
_stateController.add(LoginState.IDLE);
}
});
}
void submit (){
final email = _emailController.value;
final password = _passwordController.value;
_stateController.add(LoginState.LOADING);
FirebaseAuth.instance.signInWithEmailAndPassword(
email: email,
password: password
).catchError((e) {
_stateController.add(LoginState.FAIL);
});
}
Future<bool> verifyAdmins (FirebaseUser user) async {
return await Firestore.instance.collection('users').document(user.uid).get().then((doc)
{
if(doc.data != null){
return true;
} else {
return false;
}
}).catchError((e) {
return false;
});
}
@override
void dispose() {
_emailController.close();
_passwordController.close();
_stateController.close();
_streamSubscription.cancel();
// TODO: implement dispose
}
}
class _AdminChatState extends State<AdminChat> {
bool _isLoading = false;
void _sendMessage({String text, File imgFile}) async {
DocumentSnapshot snapshot;
FirebaseUser user = await FirebaseAuth.instance.currentUser();
Map<String, dynamic> data = {
"uid" : user.uid,
'name' : user.displayName,
'photo' : user.photoUrl,
'time' : Timestamp.now()
};
if (imgFile != null){
StorageUploadTask task = FirebaseStorage.instance.ref().child('users').child(
DateTime.now().millisecondsSinceEpoch.toString()
).putFile(imgFile);
setState(() {
_isLoading = true;
});
StorageTaskSnapshot taskSnapshot = await task.onComplete;
String url = await taskSnapshot.ref.getDownloadURL();
data['imgUrl'] = url;
setState(() {
_isLoading = false;
});
}
if(text != null) data["text"] = text;
Firestore.instance.collection("users").document(snapshot.documentID)
.collection('messages').add(data);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('hello'),
),
body: Column(
children: <Widget>[
Expanded(
child: StreamBuilder<QuerySnapshot>(
stream:
Firestore.instance.collection('users').document(widget.snapshot.documentID)
.collection('messages').orderBy('time').snapshots(),
builder: (context, snapshot){
switch(snapshot.connectionState) {
case ConnectionState.none:
case ConnectionState.waiting:
return Center(
child: CircularProgressIndicator(),
);
default:
List<DocumentSnapshot> documents =
snapshot.data.documents.reversed.toList();
return ListView.builder(
itemCount: documents.length,
reverse: true,
itemBuilder: (context, index){
// ignore: unrelated_type_equality_checks
return ChatMessage(documents[index].data, true);
});
}
},
),
),
_isLoading ? LinearProgressIndicator() : Container(),
TextComposer(_sendMessage),
],
),
);
}
}