1. 程式人生 > >【Python】Django Channels2.0 使用

【Python】Django Channels2.0 使用

簡介

  • channels2.0 可以讓django具有處理http2,websocket的能力

相關庫

  • Python3.6
  • Django 2.0
  • pip install channels
  • pip install channels_redis

配置settings.py

# 新增app
INSTALLED_APPS = (
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.sites',
    ...
'channels', ) # 繫結應用,routing.py稍後建立 ASGI_APPLICATION = "myproject.routing.application" # 設定訊息佇列,選用redis CHANNEL_LAYERS = { "default": { "BACKEND": "channels_redis.core.RedisChannelLayer", "CONFIG": { "hosts": [("localhost", 6379)], }, }, }

建立路由檔案routing.py

# routing.py

from django.urls import path

from channels.routing import ProtocolTypeRouter, URLRouter
from channels.auth import AuthMiddlewareStack

from .consumers import MyConsumer


application = ProtocolTypeRouter({

    # WebSocket chat handler
    "websocket": AuthMiddlewareStack(
        URLRouter([
            path("chart/push"
, MyConsumer), ]) ), })

建立路由處理類檔案consumers.py

# consumers.py

# -*- coding: utf-8 -*-

from channels.generic.websocket import AsyncWebsocketConsumer
# from asgiref.sync import async_to_sync


# 自定義websocket處理類
class MyConsumer(AsyncWebsocketConsumer):

    async def connect(self):
        # 建立連線時呼叫
        await self.accept()

        # 將新的連線加入到群組
        await self.channel_layer.group_add("chat", self.channel_name)


    async def receive(self, text_data=None, bytes_data=None):
        # 收到資訊時呼叫

        # 資訊單發
        # await self.send(text_data="Hello world!")

        # 資訊群發
        await self.channel_layer.group_send(
            "chat",
            {
                "type": "chat.message",
                "text": "Hello world!",
            },
        )

    async def disconnect(self, close_code):
        # 連線關閉時呼叫
        # 將關閉的連線從群組中移除
        await self.channel_layer.group_discard("chat", self.channel_name)

        await self.close()

    async def chat_message(self, event):
        # Handles the "chat.message" event when it's sent to us.
        await self.send(text_data=event["text"])

啟動Django

  • python manage.py runserver 0.0.0.0:8080

測試HTML

<!DOCTYPE HTML>
<html>
   <head>
   <meta charset="utf-8">
   <title>Django websocket</title>

      <script type="text/javascript">
         function WebSocketTest()
         {
            if ("WebSocket" in window)
            {
               alert("您的瀏覽器支援 WebSocket!");

               // 開啟一個 web socket
               var ws = new WebSocket("ws://localhost:8080/chart/push");

               ws.onopen = function()
               {
                  // Web Socket 已連線上,使用 send() 方法傳送資料
                  alert("資料傳送中...");
                  ws.send("hello world")
               };

               ws.onmessage = function (evt) 
               { 
                  var received_msg = evt.data;
                  console.log(received_msg)
               };

               ws.onclose = function()
               { 
                  // 關閉 websocket
                  alert("連線已關閉..."); 
               };
            }

            else
            {
               // 瀏覽器不支援 WebSocket
               alert("您的瀏覽器不支援 WebSocket!");
            }
         }
      </script>

   </head>
   <body>

      <div id="sse">
         <a href="javascript:WebSocketTest()">執行 WebSocket</a>
      </div>

   </body>
</html>

效果

  • 連線成功時,Django會輸出狀態,handshaking -> connect
  • 點選連線後,在console會輸出hello world