Flutter - Stream error not persisting (using bloc pattern) - flutter

Question

So I am trying to make a signup form in flutter using streams and the bloc pattern.
The problem is that the error added to the sink for one my streams does not seem to persist?
The submitValid getter does not seem to consider the error added to the passwordretype stream, this causes the login button to be clickable when it shouldn't
Steps to reproduce:
Fill out a valid email
Fill out a valid password (password field)
Fill out a valid password (password retype field)
Delete everything from the retype field
Delete everything from the password field.
Type a valid password in the password field and the login button appears clickable even though the retype field is empty.
Here's my code along with a screenshot.
Bloc.dart
import 'dart:async';
import 'package:firebase_auth/firebase_auth.dart';
import 'validators.dart';
import 'dart:io';
import 'package:rxdart/rxdart.dart';
class Bloc extends Object with Validators {
final _email = BehaviorSubject<String>();
final _password = BehaviorSubject<String>();
final _passwordretype = BehaviorSubject<String>();
final _isSignedIn = BehaviorSubject<bool>();
//Add data to stream
Stream<String> get email => _email.stream.transform(validateEmail);
Stream<String> get password => _password.stream.transform(validatePassword);
Stream<String> get passwordretype=> _passwordretype.stream.transform(validatePasswordRetype)
.doOnData((String c){
if(0 != _password.value.compareTo(c)){
_passwordretype.addError("Passwords do not match");
}
});
Stream<bool> get signInStatus => _isSignedIn.stream;
Stream<bool> get submitValid =>
Rx.combineLatest3(email, password, passwordretype, (e, p, r) => true);
//Change data
Function(String) get changeEmail => _email.sink.add;
Function(String) get changePassword => _password.sink.add;
Function(String) get changePasswordRetype => _passwordretype.sink.add;
Function(bool) get showProgressBar => _isSignedIn.add;
register() async {
final FirebaseAuth _auth = FirebaseAuth.instance;
try {
showProgressBar(true);
final FirebaseUser user = (await _auth.createUserWithEmailAndPassword(
email: _email.value,
password: _password.value,
))
.user;
if (user != null) {
// setState(() {
// _success = true;
// _userEmail = user.email;
// Navigator.of(context).pushNamedAndRemoveUntil(
// '/home', (Route<dynamic> route) => false);
//
//// Navigator.of(context).pushReplacementNamed('/home');
//
// });
} else {
// Scaffold.of(context).showSnackBar(SnackBar(
// content: Text("Error occured, please try again later"),
// ));
// _success = false;
}
} catch (err) {
_isSignedIn.addError(err);
print(err);
// setState(() {
// _showLoading = false;
// _error = true;
// });
}
}
dispose() {
_email.drain();
_email.close();
_password.drain();
_password.close();
_passwordretype.drain();
_passwordretype.close();
}
}
SignupScreen.dart
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:lendy/src/blocs/bloc.dart';
import 'package:lendy/src/blocs/provider.dart';
class SignupScreen extends StatelessWidget {
// final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
// final TextEditingController _emailController = TextEditingController();
// final TextEditingController _passwordController = TextEditingController();
// final TextEditingController _passwordController2 = TextEditingController();
final FirebaseAuth _auth = FirebaseAuth.instance;
// final GoogleSignIn _googleSignIn = GoogleSignIn();
String _userID = "";
bool _success;
String _userEmail;
#override
Widget build(BuildContext context) {
final bloc = Provider.of(context);
return Scaffold(
appBar: AppBar(
title: Text("Signup"),
),
body: Container(
child: Column(
children: <Widget>[
emailField(bloc),
passwordField(bloc),
passwordFieldRe(bloc),
SizedBox(
height: 10.0,
),
button(bloc)
],
),
),
);
}
Widget emailField(Bloc bloc) {
return StreamBuilder(
stream: bloc.email,
builder: (context, snapshot) {
return TextField(
onChanged: bloc.changeEmail,
keyboardType: TextInputType.emailAddress,
decoration: InputDecoration(
hintText: 'Enter email address',
labelText: 'Email-address',
errorText: snapshot.error),
);
},
);
}
Widget passwordField(Bloc bloc) {
return StreamBuilder(
stream: bloc.password,
builder: (context, snapshot) {
return TextField(
onChanged: bloc.changePassword,
decoration: InputDecoration(
hintText: 'Enter password',
labelText: 'Password',
errorText: snapshot.error),
);
});
}
Widget passwordFieldRe(Bloc bloc) {
return StreamBuilder(
stream: bloc.passwordretype,
builder: (context, snapshot) {
return TextField(
onChanged: bloc.changePasswordRetype,
decoration: InputDecoration(
hintText: 'Retype password',
labelText: 'Password',
errorText: snapshot.error),
);
});
}
Widget button(Bloc bloc) {
return StreamBuilder(
stream: bloc.submitValid,
builder: (context, snapshot) {
return RaisedButton(
child: Text('Register'),
color: Colors.blue,
//if true
onPressed: snapshot.hasData
? () {
// bloc.showProgressBar(true);
bloc.register();
}
: null);
},
);
}
Widget buttons(Bloc bloc) {
return StreamBuilder(
stream: bloc.submitValid,
builder: (context, snapshot1) {
return StreamBuilder(
stream: bloc.signInStatus,
builder: (context, snapshot2) {
if (!snapshot2.hasData || snapshot2.hasError) {
return Column(
children: <Widget>[
RaisedButton(
child: Text('Register'),
color: Colors.blue,
onPressed: snapshot1.hasData
? () {
bloc.register();
}
: null,
),
snapshot2.hasError ? Text("ee") : Container()
],
);
} else {
return CircularProgressIndicator();
}
},
);
},
);
}
Widget submitButton(Bloc bloc) {
return StreamBuilder(
stream: bloc.signInStatus,
builder: (context, snapshot) {
if (snapshot.hasError || !snapshot.hasData) {
return buttons(bloc);
} else {
return CircularProgressIndicator();
}
});
}
/
Validators.dart
import 'dart:async';
class Validators {
final validateEmail = StreamTransformer<String, String>.fromHandlers(
handleData: (email, sink){
if (RegExp(
r"^[a-zA-Z0-9.a-zA-Z0-9.!#$%&'*+-/=?^_`{|}~]+#[a-zA-Z0-9]+\.[a-zA-Z]+")
.hasMatch(email)){
sink.add(email);
} else {
sink.addError('Please enter a valid email address.');
}
}
);
final validatePassword = StreamTransformer<String, String>.fromHandlers(
handleData: (password, sink){
if (password.length > 3){
sink.add(password);
} else {
sink.addError('Password is too short.');
}
}
);
final validatePasswordRetype = StreamTransformer<String, String>.fromHandlers(
handleData: (password, sink){
print("HANDLE DATA");
if (password.length > 3){
sink.add(password);
} else {
sink.addError('Password is too short.');
}
}
);
}
screenshot

Answer 1

For the submitValid Stream you are using the BehaviorSubjects instead of use the stream.transforms, so for that reason, your submitValid doesn't receive the errors. Replace your submitValid with the next code:
Stream<bool> get submitValid => Rx.combineLatest3(email, password, passwordretype, (e, p, r) => true);

Answer 2

Found a similar issue here
I changed my submitValid function like so:
Stream<bool> get submitValid =>
Rx.combineLatest3(email, password, passwordretype, (e, p, r) {
if (p == _password.value && r == _passwordretype.value){
return true;
} else {
return false;
}
});
And changed onPressed in my button Widget like so. It only renders the clickable button if the snapshot returns true.
Widget button(Bloc bloc) {
return StreamBuilder(
stream: bloc.submitValid,
builder: (context, snapshot) {
return RaisedButton(
child: Text('Register'),
color: Colors.blue,
onPressed: snapshot.hasData && snapshot.data
? () {
bloc.register();
}
: null);
},
);
}