Django Channels配置记录

官方文档：https://channels.readthedocs.io/en/latest/tutorial/index.html

django版本：4.1
channels版本：3.0.5

一、安装各种包&创建APP

1.安装channels、channels-redis（用于验证连接redis）
2.安装Redis Vers.>=5，小于5会报错unknown command ‘BZPOPMIN’
windows上的redis地址

redis-x64-50141.zip

12MB

# 使用帮助：
1.注册到服务：redis-server --service-install redis.windows.conf
2.进入“服务”，找到Redis，右键点击开启

Redis使用：
卸载服务：redis-server --service-uninstall
开启服务：redis-server --service-start
停止服务：redis-server --service-stop

# 测试连接（需安装channels-redis），打开pycharm里的python控制台：
>>> import channels.layers
>>> channel_layer = channels.layers.get_channel_layer()
>>> from asgiref.sync import async_to_sync
>>> async_to_sync(channel_layer.send)('test_channel', {'type': 'hello'})
>>> async_to_sync(channel_layer.receive)('test_channel')
{'type': 'hello'}

3.新建名字叫chat的app：python manage.py startapp chat

二、配置settings.py

1.配置INSTALLED_APPS

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

2.配置ASGI_APPLICATION 和Redis

# settings.py最后面
# Channels
ASGI_APPLICATION = 'djangoProject.asgi.application'
CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels_redis.core.RedisChannelLayer',
        'CONFIG': {
            "hosts": [('127.0.0.1', 6379)],
        },
    },
}

三、配置asgi.py

（django2.2以下木有自带的asgi.py，需要自建，且要django.setup()）

import os

from channels.auth import AuthMiddlewareStack
from channels.routing import ProtocolTypeRouter, URLRouter
from channels.security.websocket import AllowedHostsOriginValidator
from django.core.asgi import get_asgi_application

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'djangoProject.settings')
# Initialize Django ASGI application early to ensure the AppRegistry
# is populated before importing code that may import ORM models.
django_asgi_app = get_asgi_application()

import chat.routing

application = ProtocolTypeRouter({
    "http": get_asgi_application(),
    # 使用chat下的routing来处理websocket
    "websocket": AllowedHostsOriginValidator(
            AuthMiddlewareStack(
                URLRouter(
                    chat.routing.websocket_urlpatterns
                )
            )
        ),
})

配置好后，需要执行migrate：python manage.py migrate

四、配置templates

1.配置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>

2.配置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">
    {{ room_name|json_script:"room-name" }}
    <script>
        const roomName = JSON.parse(document.getElementById('room-name').textContent);

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

        chatSocket.onmessage = function(e) {
            const data = JSON.parse(e.data);
            document.querySelector('#chat-log').value += (data.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) {
            const messageInputDom = document.querySelector('#chat-message-input');
            const message = messageInputDom.value;
            chatSocket.send(JSON.stringify({
                'message': message
            }));
            messageInputDom.value = '';
        };
    </script>
</body>
</html>

五、配置urls.py和routing.py

1.配置主urls.py

from django.contrib import admin
from django.urls import path, include


urlpatterns = [
    path('admin/', admin.site.urls),
    path("chat/", include("chat.urls")),
]

2.配置chat里的urls.py

from django.urls import path
from . import views
urlpatterns = [
    path('', views.index, name='index'),
    path('<str:room_name>/', views.room, name='room'),  # str后不要有空格
]

3.新建routing.py

from django.urls import re_path

from . import consumers

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

六、配置view.py和consumers.py

1.配置views.py

from django.shortcuts import render


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


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

2.新建consumers.py（处理ws请求的核心）

# —————————————————————————————这里为同步代码（官方文档第2部分）—————————————————————————————
# import json
# from asgiref.sync import async_to_sync
# from channels.generic.websocket import WebsocketConsumer
#
#
# class ChatConsumer(WebsocketConsumer):
#     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
#         async_to_sync(self.channel_layer.group_add)(
#             self.room_group_name,
#             self.channel_name
#         )
#
#         self.accept()
#
#     def disconnect(self, close_code):
#         # Leave room group
#         async_to_sync(self.channel_layer.group_discard)(
#             self.room_group_name,
#             self.channel_name
#         )
#
#     # Receive message from WebSocket
#     def receive(self, text_data):
#         text_data_json = json.loads(text_data)
#         message = text_data_json['message']
#
#         # Send message to room group
#         async_to_sync(self.channel_layer.group_send)(
#             self.room_group_name,
#             {
#                 'type': 'chat_message',
#                 'message': message
#             }
#         )
#
#     # Receive message from room group
#     def chat_message(self, event):
#         message = event['message']
#
#         # Send message to WebSocket
#         self.send(text_data=json.dumps({
#             'message': message
#         }))


# —————————————————————————————以下为异步代码（官方文档第3部分）—————————————————————————————


import json
from channels.generic.websocket import AsyncWebsocketConsumer


class ChatConsumer(AsyncWebsocketConsumer):
    """
    Differences:
    ChatConsumer now inherits from AsyncWebsocketConsumer rather than WebsocketConsumer.
    All methods are async def rather than just def.
    await is used to call asynchronous functions that perform I/O.
    async_to_sync is no longer needed when calling methods on the channel layer.
    """
    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
        }))

# Django Channels配置记录