Handle callback response from Post method with bloc - flutter

Question

I am calling login api on button click, I am able to get response from server but on clicking on button ,i am not able to received response.How can i receive the response and handle it .I am using BLoC pattern for this. Here is the code,
import 'package:flutter/material.dart';
import '../blocs/bloc.dart';
import '../blocs/provider.dart';
import '../models/login_response.dart';
class LoginScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Provider(
child: new Scaffold(
body: Container(
child: LoginForm(),
),
),
);
}
}
class LoginForm extends StatefulWidget {
// since its a stateful widget we need to create state for it.
const LoginForm({Key key}) : super(key: key);
#override
_LoginFormState createState() => _LoginFormState();
}
class _LoginFormState extends State<LoginForm> {
#override
Widget build(BuildContext context) {
return Form(
child: Column(
children: <Widget>[
Padding(
padding: const EdgeInsets.only(top: 50),
),
// Start creating widget here.
emailField(),
passwordField(),
Container(margin: EdgeInsets.only(top: 25.0)),
submitButton()
],
),
);
}
Widget emailField() {
return StreamBuilder(
stream: bloc.email,
builder: (context, snapshot) {
return TextField(
onChanged: bloc.changeEmail,
keyboardType: TextInputType.emailAddress,
decoration: InputDecoration(
hintText: 'you#example.com',
labelText: 'Email Address',
errorText: snapshot.error
),
);
}
);
}
Widget passwordField() {
return StreamBuilder(
stream: bloc.password,
builder: (context, snapshot) {
return TextField(
onChanged: bloc.changePassword,
obscureText: true,
decoration: InputDecoration(
labelText: 'Please enter your password',
hintText: 'Password',
errorText: snapshot.error
),
);
},
);
}
Widget submitButton() {
return StreamBuilder(
stream: bloc.submitValid,
builder: (context, snapshot) {
return RaisedButton(
onPressed:() => showWidgetForNetworkCall(context),
// onPressed: () {
// // Do submit button action.
// showWidgetForNetworkCall(context);
// // callLoginApi();
// },
child: const Text('Login'),
textColor: Colors.white,
color: Colors.blueAccent,
);
},
);
}
// Loading Widget
Widget _buildLoadingWidget() {
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text("Loading data from API...", textDirection: TextDirection.ltr), CircularProgressIndicator()
],
),
);
}
// // Error Widget
Widget _buildErrorWidget(String error) {
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text("Loading error data from API...", textDirection: TextDirection.ltr), CircularProgressIndicator()
],
),
);
}
// show server data
showServerData() {
print(" Servr >>>>>> Data : ");
}
Widget showWidgetForNetworkCall(BuildContext context) {
bloc.loginSubmit();
return StreamBuilder(
stream: bloc.loginSubject.stream,
builder: (context, AsyncSnapshot<LoginResponse>snapshot){
if (snapshot.hasData) {
return showServerData();
} else if (snapshot.hasError) {
return _buildErrorWidget(snapshot.error);
} else {
return _buildLoadingWidget();
}
},
);
}
}
This is my login_screen.dart. And my bloc class for api call is:
postData() async {
LoginResponse response = await _repository.postData(_loginResource);
_subject.sink.add(response);
}
code of bloc
import 'dart:async';
import 'package:rxdart/rxdart.dart';
import 'validators.dart';
import '../models/login_response.dart';
import '../repository/login_repository.dart';
import '../resources/login_resource.dart';
class Bloc extends Object with Validators {
final LoginRepository _repository = LoginRepository();
final BehaviorSubject<LoginResponse> _subject =
BehaviorSubject<LoginResponse>();
LoginResource _loginResource = LoginResource();
final _email = BehaviorSubject<String>(); // Declaring variable as private
final _password = BehaviorSubject<String>(); // Declaring variable as private
// Add data to stream (Its like setter)
Stream<String> get email => _email.stream.transform(validateEmail);
Stream<String> get password =>
_password.stream.transform(validatePassword);
Stream<bool> get submitValid => Observable.combineLatest2(email, password, (e, p) => true);
// Change data. For retrieveing email value.
Function(String) get changeEmail => _email.sink.add;
Function(String) get changePassword => _password.sink.add;
loginSubmit() {
_loginResource.email = "bar1";
_loginResource.password = "bar2";
postData();
}
postData() async {
LoginResponse response = await _repository.postData(_loginResource);
_subject.sink.add(response);
}
dispose() {
_email.close();
_password.close();
_subject.close();
}
BehaviorSubject<LoginResponse> get loginSubject => _subject;
}
final bloc = Bloc();