Merge pull request #91 from auguzsto/master

Adding example for flutter application.

example/example_flutter.dart

@@ -0,0 +1,98 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:stomp_dart_client/stomp.dart';
+import 'package:stomp_dart_client/stomp_config.dart';
+import 'package:stomp_dart_client/stomp_frame.dart';
+
+void main() {
+  runApp(const MaterialApp(
+    home: HomePage(),
+  ));
+}
+
+class HomePage extends StatefulWidget {
+  const HomePage({super.key});
+
+  @override
+  State<HomePage> createState() => _HomePageState();
+}
+
+class _HomePageState extends State<HomePage> {
+  late StompClient stompClient;
+
+  // WebSocket Server with SockJS
+  String socketUrlSockJS = "http://localhost:8080/ws-message";
+
+  // WebSocket Server without SockJS
+  String socketUrl = "ws://localhost:8080/ws-message";
+
+  // String to change in listener Subscription
+  String message = '';
+
+  // Subscription
+  void onConnect(StompClient stompClient, StompFrame stompFrame) {
+    stompClient.subscribe(
+      destination: '/topic/message',
+      callback: (frame) {
+        if (frame.body != null) {
+          // Here changes the state in screen
+          setState(() {
+            Map<String, dynamic> result = jsonDecode(frame.body!);
+            message = result['message'];
+          });
+        }
+      },
+    );
+  }
+
+  @override
+  void initState() {
+    super.initState();
+
+    // Configuration client with SockJS.
+    stompClient = StompClient(
+      config: StompConfig.SockJS(
+        url: socketUrlSockJS,
+        onConnect: (stompFrame) => onConnect(stompClient, stompFrame),
+      ),
+    );
+
+    // Configuration client without SockJS.
+    // stompClient = StompClient(
+    //   config: StompConfig(
+    //     url: socketUrl,
+    //     onConnect: (stompFrame) => onConnect(stompClient, stompFrame),
+    //   ),
+    // );
+
+    stompClient.activate();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text("Stomp Client Demo"),
+      ),
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Text(
+              "Your message from server:",
+              style: Theme.of(context).textTheme.bodyLarge,
+            ),
+            Text(message),
+          ],
+        ),
+      ),
+    );
+  }
+
+  @override
+  void dispose() {
+    stompClient.deactivate();
+    super.dispose();
+  }
+}