使用Django Channels构建WebSocket应用程序
在使用Django Channels构建WebSocket应用程序之前,需要先安装Channels:
pip install channels
在settings.py中加入以下配置:
INSTALLED_APPS = [ # ... 'channels', ]
ASGI_APPLICATION = 'your_project_name.routing.application'
然后,在你的应用程序目录中创建一个名为routing.py的文件,内容如下:
from channels.routing import ProtocolTypeRouter, URLRouter from django.urls import path from . import consumers websocket_urlpatterns = [ path('ws/<str:room_name>/', consumers.ChatConsumer.as_asgi()), ] application = ProtocolTypeRouter({ 'websocket': URLRouter(websocket_urlpatterns) })
这里我们定义了一个名为“ChatConsumer”的消费者类,并让它处理所有的WebSocket请求。
下一步是实现上述ChatConsumer类。在你的应用程序目录中创建一个名为consumers.py的文件,内容如下:
from channels.generic.websocket import AsyncWebsocketConsumer class ChatConsumer(AsyncWebsocketConsumer): async def connect(self): self.room_name = self.scope['url_route']['kwargs']['room_name'] self.room_group_name = 'chat_%s' % self.room_name # Join room group await self.channel_layer.group_add( self.room_group_name, self.channel_name ) await self.accept() async def disconnect(self, close_code): # Leave room group await self.channel_layer.group_discard( self.room_group_name, self.channel_name ) async def receive(self, text_data): # Receive message from WebSocket text_data_json = json.loads(text_data) message = text_data_json['message'] # Send message to room group await self.channel_layer.group_send( self.room_group_name, { 'type': 'chat_message', 'message': message } ) # Receive message from room group async def chat_message(self, event): message = event['message'] # Send message to WebSocket await self.send(text_data=json.dumps({ 'message': message }))
在我们的ChatConsumer中实现了三个方法:connect(),disconnect()和receive()。
接下来,在模板文件中,我们在JavaScript中创建一个WebSocket对象,连接到chat房间。
<!doctype html> <html> <head> <meta charset="UTF-8"> <title>Django Channels Chat Room</title> <script> var roomName = 'pidancode.com'; var webSocketBridge = new channels.WebSocketBridge(); webSocketBridge.connect('/ws/' + roomName); webSocketBridge.listen(function (data) { console.log("Received: " + data.message); }); function sendMessage(message) { webSocketBridge.send({ "message": message }); } </script> </head> <body> <h1>Django Channels Chat Room</h1> <div id="chat"> <input type="text" id="message"> <button onclick="sendMessage(document.getElementById('message').value)">Send</button> </div> </body> </html>
这里我们创建了一个名为“webSocketBridge”的连接,将其连接到chat房间。sendMessage()函数用于发送消息。
这就是用Django Channels构建WebSocket应用程序的基本示例。
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