详解Django-channels 实现WebSocket实例

不要因为一时的失败和挫折,就忘记以往壮志满满说过要去的远方。人皆有爱生恶死之心,人皆为舍生取死之道。何也见善不明耳。

引入

先安装三个模块

pip install channels

pip install channels_redis

pip install pywin32

创建一个Django项目和一个app

项目名随意,app名随意。这里项目名为django_websocket_demo ,app名chat

把app文件夹下除了views.py 和__init__.py 的文件都删了,最终项目目录结构如下:

django_websocket_demo/
  manage.py
  django_websocket_demo/
    __init__.py
    settings.py
    urls.py
    wsgi.py
  chat/
    __init__.py
    views.py

在app下新建一个templates文件夹用来存放HTML页面:

chat/
  __init__.py
  templates/
    chat/
      index.html
  views.py

index.html 内容如下:

<!-- chat/templates/chat/index.html -->
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8"/>
  <title>Chat Rooms</title>
</head>
<body>
  What chat room would you like to enter?<br/>
  <input id="room-name-input" type="text" size="100"/><br/>
  <input id="room-name-submit" type="button" value="Enter"/>

  <script>
    document.querySelector('#room-name-input').focus();
    document.querySelector('#room-name-input').onkeyup = function(e) {
      if (e.keyCode === 13) { // enter, return
        document.querySelector('#room-name-submit').click();
      }
    };

    document.querySelector('#room-name-submit').onclick = function(e) {
      var roomName = document.querySelector('#room-name-input').value;
      window.location.pathname = '/chat/' + roomName + '/';
    };
  </script>
</body>
</html>

在chat/views.py 中添加视图函数:

from django.shortcuts import render

def index(request):
  return render(request, 'chat/index.html', {})

添加chat/urls.py 文件并设置路由信息:

from django.urls import re_path

from . import views

urlpatterns = [
  re_path(r'^$', views.index, name='index'),
]

在项目路由django_websocket_demo/urls.py 中配置路由信息:

from django.conf.urls import include, url
from django.contrib import admin

urlpatterns = [
  url(r'^chat/', include('chat.urls')),
  url(r'^admin/', admin.site.urls),
]

在settings.py 文件同级目录下新建routing.py 文件,内容如下:

from channels.routing import ProtocolTypeRouter

application = ProtocolTypeRouter({
  # (http->django views is added by default)
})

把channels 注册在settings.py 里:

INSTALLED_APPS = [
  'channels',
  'chat',
  'django.contrib.admin',
  'django.contrib.auth',
  'django.contrib.contenttypes',
  'django.contrib.sessions',
  'django.contrib.messages',
  'django.contrib.staticfiles',
]

在 settings.py 文件中,添加如下配置项:

# django_websocket_demo/settings.py
# Channels
# Channels
ASGI_APPLICATION = 'django_websocket_demo.routing.application'

创建聊天页面

创建一个chat/templates/chat/room.html 文件,添加如下内容:

<!-- chat/templates/chat/room.html -->
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8"/>
  <title>Chat Room</title>
</head>
<body>
  <textarea id="chat-log" cols="100" rows="20"></textarea><br/>
  <input id="chat-message-input" type="text" size="100"/><br/>
  <input id="chat-message-submit" type="button" value="Send"/>
</body>
<script>
  var roomName = {{ room_name_json }};

  var chatSocket = new WebSocket(
    'ws://' + window.location.host +
    '/ws/chat/' + roomName + '/');

  chatSocket.onmessage = function(e) {
    var data = JSON.parse(e.data);
    var message = data['message'];
    document.querySelector('#chat-log').value += (message + '\n');
  };

  chatSocket.onclose = function(e) {
    console.error('Chat socket closed unexpectedly');
  };

  document.querySelector('#chat-message-input').focus();
  document.querySelector('#chat-message-input').onkeyup = function(e) {
    if (e.keyCode === 13) { // enter, return
      document.querySelector('#chat-message-submit').click();
    }
  };

  document.querySelector('#chat-message-submit').onclick = function(e) {
    var messageInputDom = document.querySelector('#chat-message-input');
    var message = messageInputDom.value;
    chatSocket.send(JSON.stringify({
      'message': message
    }));

    messageInputDom.value = '';
  };
</script>
</html>

在chat/views.py 中添加一个处理 room的视图函数:

from django.shortcuts import render
from django.utils.safestring import mark_safe
import json

def index(request):
  return render(request, 'chat/index.html', {})

def room(request, room_name):
  return render(request, 'chat/room.html', {
    'room_name_json': mark_safe(json.dumps(room_name))
  })

在chat/urls.py 中注册路由

from django.urls import re_path

from . import views

urlpatterns = [
  re_path(r'^$', views.index, name='index'),
  re_path(r'^(?P<room_name>[^/]+)/$', views.room, name='room'),
]

新建chat/consumers.py 文件,添加如下内容:

from channels.generic.websocket import AsyncWebsocketConsumer
import json

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
    )

  # Receive message from WebSocket
  async def receive(self, text_data):
    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
    }))

新建一个chat/routing.py 文件,添加以下内容:

from django.urls import re_path

from . import consumers

websocket_urlpatterns = [
  re_path(r'^ws/chat/(?P<room_name>[^/]+)/$', consumers.ChatConsumer),
]

将django_websocket_demo/routing.py 文件中修改为以下内容:

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

application = ProtocolTypeRouter({
  # (http->django views is added by default)
  'websocket': AuthMiddlewareStack(
    URLRouter(
      chat.routing.websocket_urlpatterns
    )
  ),
})

配置redis

在本地6379端口启动redis :redis-server

在settings.py 中添加如下配置:

CHANNEL_LAYERS = {
  'default': {
    'BACKEND': 'channels_redis.core.RedisChannelLayer',
    'CONFIG': {
      "hosts": [('127.0.0.1', 6379)],
    },
  },
}

最后启动Django项目

使用多个浏览器打开http://127.0.0.1:8000/chat/lobby/ ,开始实时聊天吧。

本文详解Django-channels 实现WebSocket实例到此结束。人生充满苦痛,我们有幸来过。小编再次感谢大家对我们的支持!

标签: Django channels