implementing simple rxDart with Bloc don't get result

from this link on my web server as

i'm trying to get result and printing avatar from that result, unfortunately my implementation with rxDart and Bloc don't get result from this response and i don't get any error

server response this simplified result:

{
  "active": 1,
  "name": "my name",
  "email": " 3 ",
  "loginType": " 3 ",
  "mobile_number": " 3 ",

  ...

  "api_token": "1yK3PvAsBA6r",
  "created_at": "2019-02-12 19:06:34",
  "updated_at": "2019-02-12 19:06:34"
}

main.dart file: (click on button to get result from server)

StreamBuilder(
  stream: bloc.login,
  builder: (context,
      AsyncSnapshot<UserInfo>
      snapshot) {
    if (snapshot.hasData) {
      parseResponse(snapshot);
    }
  },
);
void parseResponse(AsyncSnapshot<UserInfo> snapshot) {
  debugPrint(snapshot.data.avatar);
}

LoginBlock class:

class LoginBlock{
  final _repository = Repository();
  final _login_fetcher = PublishSubject<UserInfo>();

  Observable<UserInfo> get login=>_login_fetcher.stream;

  fetchLogin() async{
    UserInfo userInfo = await _repository.userInfo();
    _login_fetcher.sink.add(userInfo);
  }

  dispose(){
    _login_fetcher.close();
  }
}

final bloc = LoginBlock();

Repository class:

class Repository {
  final userInformation = InstagramApiProviders();

  Future<UserInfo> userInfo() => userInformation.checkUserLogin();
}

my model:

class UserInfo {
  int _active;
  String _name;
  ...

  UserInfo.fromJsonMap(Map<String, dynamic> map)
      : _active = map["active"],
        _name = map["name"],
        ...

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['active'] = _active;
    data['name'] = _name;
    ...

    return data;
  }

  //GETTERS
}

BaseUrl class:

class BaseUrl {
  static const url = 'http://instamaker.ir';
}

and then InstagramApiProviders class:

class InstagramApiProviders {
  Client client = Client();

  Future<UserInfo> checkUserLogin() async {
    final response = await client.get(BaseUrl.url+'/api/v1/getPersons');
    print("entered  "+BaseUrl.url+'/api/v1/getPersons');
    if (response.statusCode == 200) {
      return UserInfo.fromJsonMap(json.decode(response.body));
    } else
      throw Exception('Failed to load');
  }
}

Solution

Well the answer here is part of the test that I make to get this done. I can put my all test here but I think that the problem cause was because as StreamBuilder is a widget his builder method callback is only called when the widget is in flutter widget tree. As in your sample you're just creating a StreamBuilder the builder method will never be called bacause this widget isn't in widget tree.

As advice first test your code changing only UI layer... do somenthing like:

@override
  Widget build(BuildContext context) {

    return Scaffold(
      appBar: AppBar(
        actions: <Widget>[
          IconButton(icon: Icon(Icons.assessment), onPressed: () => loginBlock.fetchLogin()),
        ],
      ),
      body: StreamBuilder<UserInfo>(
        stream: loginBlock.login,
        builder: (context, snapshot){
          if (snapshot.hasData){
            parseResponse(snapshot);
            return Text('user: ${snapshot.data.name} ');
          }
          if (snapshot.hasError)
            return Text('${snapshot.error}');
          else return Text('There is no data');
        },
      ),
    );

Here we're putting the StreamBuilder in widget tree so the builder callback is called and maybe you will see the results. If it fails, please comment that I update my answer with my full test code with this working.

Updating the answer with sources that I made tests.

Basic model

class UserInfo {
  int _active;
  String name;

  UserInfo.fromJsonMap(Map<String, dynamic> map) {
    _active = map["active"];
    name = map["name"];
  }

  Map<String, dynamic> toJson() => {
    'active' : _active,
    'name' : name,
  };
}

The provider class

class InstagramApiProviders {
  Future<UserInfo> checkUserLogin() async {

    UserInfo info;

    try {
      http.Response resp = await http.get("http://instamaker.ir/api/v1/getPersons");
      if (resp.statusCode == 200){
        print('get response');
        print( resp.body );
        info = UserInfo.fromJsonMap(  Map.from(  json.decode(resp.body ) ));
      }
    }
    catch (ex) {
      throw ex;
    }
    print('returning $info');
    return info;
  }
}

Repository

class Repository {
  final userInformation = InstagramApiProviders();
  Future<UserInfo> userInfo() => userInformation.checkUserLogin().then((user) => user);
}

BLoC class

class LoginBlock{
  final _repository = Repository();
  final _login_fetcher = PublishSubject<UserInfo>();

  Observable<UserInfo> get login=>_login_fetcher.stream;

  fetchLogin() async {
    UserInfo info = await _repository.userInfo();
      _login_fetcher.sink.add(info);
  }

  dispose(){
    _login_fetcher.close();
  }
}

Widget UI

This starts showing There is no data message but when you hit appBar button wait a little and then the data is fetched and updates the UI.

class WidgetToShowData extends StatelessWidget {

  final LoginBlock bloc = LoginBlock();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        actions: <Widget>[
          IconButton(icon: Icon(Icons.assessment), onPressed: () => loginBlock.fetchLogin()),
        ],
      ),
      body: StreamBuilder<UserInfo>(
        stream: loginBlock.login,
        builder: (context, snapshot){
          if (snapshot.hasData){
            parseResponse(snapshot);
            return Text('user: ${snapshot.data.name} ');
          }
          if (snapshot.hasError)
            return Text('${snapshot.error}');
          else return Text('There is no data');
        },
      ),
    );
  }

  void parseResponse(AsyncSnapshot<UserInfo> snapshot) {
    debugPrint(snapshot.data.name);
  }
}