Flutter WebSocketChannel without StreamBuilder

WebSocketChannel is a powerful tool for real-time bidirectional communication between the client and server. It is widely used in many applications including chat applications, gaming applications, and more. In this guide, we will discuss how to use WebSocketChannel without StreamBuilder in Flutter.

What is WebSocketChannel?

WebSocketChannel is a library in Flutter that provides a web socket implementation of the StreamChannel class. It is used for bi-directional communication between a client and the server. It has many features including support for sending and receiving data, error handling, and message mapping.

Why use WebSocketChannel without StreamBuilder?

StreamBuilder is a widget in Flutter that provides a simplified way to listen to streams of data that can be displayed in a widget. However, when using WebSocketChannel, StreamBuilder can cause issues when handling the stream of data that is received from the server. When WebSocketChannel receives data from the server, it sends it to the stream and StreamBuilder displays it in the widget. However, when StreamBuilder is used for displaying large amounts of data, it can cause performance issues on the client-side.

How to use WebSocketChannel without StreamBuilder?

To use WebSocketChannel without StreamBuilder, we need to manually manage the stream of data that is received from the server. We can do this by using the StreamSubscription class, which allows us to listen to streams of data and handle it accordingly.

// First, import the necessary libraries
import 'package:flutter/material.dart';
import 'package:web_socket_channel/web_socket_channel.dart';
import 'dart:async';

class MyWebSocket extends StatefulWidget {
  @override
  MyWebSocketState createState() => MyWebSocketState();
}

class MyWebSocketState extends State<MyWebSocket> {
  // Define the WebSocketChannel
  WebSocketChannel channel =
      WebSocketChannel.connect(Uri.parse('ws://localhost:8080'));

  // Define the StreamSubscription
  StreamSubscription streamSubscription;

  // Define our message variable
  String message = '';

  @override
  void initState() {
    super.initState();

    // Set up the StreamSubscription to listen to the stream of data
    streamSubscription = channel.stream.listen((event) {
      setState(() {
        message = event.toString();
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('WebSocketChannel without StreamBuilder'),
      ),
      body: Center(
        child: Text(message),
      ),
    );
  }

  @override
  void dispose() {
    super.dispose();

    // Cancel the StreamSubscription when we're done
    streamSubscription.cancel();
    channel.sink.close();
  }
}

In the example above, we have manually managed the stream of data that is received from the server. We have created a StreamSubscription to listen to the stream of data and set up a callback function to handle it accordingly. We are also manually updating the state of our widget when new data is received from the server.

Conclusion

WebSocketChannel is a powerful tool for real-time bidirectional communication between the client and server. By using it without StreamBuilder, we can have more control over the stream of data that is received from the server, which can result in improved performance of our Flutter application.