Flutter streamsocket

Question

I had a problem to read a data from a stream socket. After receiveing data in a websocket call, I want put all my content in a variable and start to using that wariable. Instead, I can print only the last string line in the body of the app. To socket connect I use socket.io-client dependency version ^1.0.1 and it works. The problem is the next step, how can get the data from the socket.

I can I print all the content of the StreamSocket?

import 'package:flutter/material.dart';
import 'package:vincenzakart/widget/navigationdrawerwidget.dart';
import 'package:socket_io_client/socket_io_client.dart' as IO;
import 'dart:async';
import 'dart:io';

class PilotiPage extends StatefulWidget {
  const PilotiPage({Key? key}) : super(key: key);

  @override
  PilotiPageState createState() => PilotiPageState();
}

StreamSocket streamSocket = StreamSocket();
var datiDaServer;

class PilotiPageState extends State<PilotiPage> {
  @override
  void initState() {
    super.initState();
    initSocket();
  }

  @override
  Widget build(BuildContext context) => Scaffold(
        drawer: const NavigationDrawerWidget(),
        appBar: AppBar(
          title: const Text('Piloti'),
          centerTitle: true,
          backgroundColor: Colors.black12,
        ),
        body: Container(
          child: StreamBuilder(
            stream: streamSocket.getResponse,
            builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
              return Column(
                children: [
                  Text(datiDaServer.toString()),
                ],
              );
            },
          ),
        ),
      );
}

@override
void initSocket() {
  connectAndListen();
}

// STEP1:  Stream setup
class StreamSocket {
  final _socketResponse = StreamController<String>();
  void Function(String) get addResponse => _socketResponse.sink.add;
  Stream<String> get getResponse => _socketResponse.stream;
  void dispose() {
    _socketResponse.close();
  }
}


void connectAndListen() {
  IO.Socket socket = IO.io('http://192.168.110.204:3999',
      IO.OptionBuilder().setTransports(['websocket']).build());

  socket.connect();
  socket.onConnect((_) {
    print('connect socket.io');
    print(socket.id);
  });

  //When an event recieved from server, data is added to the stream
  socket.on('message', (data) => streamSocket.addResponse);
  socket.on('message', (data) {
    print(data.toString());
    print(data.toString().length);
    datiDaServer = data;
  });

  socket.onDisconnect((_) => print('disconnect'));
}

score 0 · Answer 1 · answered Oct 26 '21 at 10:52

I get the response I want just doing a little change. In the variable declaration I wrote:

String datiDaServer = ''

instead of var datiDaServer

and in function void connectAndListen() I wrote datiDaServer += data.toString(); instead of datiDaServer = data.toString()

I know this is a very dirty way, but at the moment works fine for what I have to do.

Flutter streamsocket

1 Answers1