django channle的使用

频道在PyPI上可用 - 要安装它，只需运行：   参照：https://channels.readthedocs.io/en/latest/introduction.html

pip install -U channels

安装 channels_redis

pip install channels_redis

安装redis:   windows 参照 https://www.cnblogs.com/juncaoit/p/10122642.html
            ubuntu 参照以下命令

apt-get install redis-server

完成后，您应该添加channels到您的 INSTALLED_APPS设置：

INSTALLED_APPS = (
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.sites',
    ...
    'channels',
)

然后，在以下位置进行默认路由myproject/routing.py：

# mysite/routing.py
from channels.auth import AuthMiddlewareStack
from channels.routing import ProtocolTypeRouter, URLRouter
import apiService.routing

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

最后，将您的ASGI_APPLICATION设置设置为指向该路由对象作为根应用程序：

ASGI_APPLICATION = "myproject.routing.application"

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

一旦启用本地服务，channels也将在响应的端口启用ws服务 （服务器上则不同）

apiService中的路由：

# chat/routing.py
# from django.urls import path
from django.conf.urls import url
from . import consumers,admin_ws

websocket_urlpatterns = [
    # path('ws/admin_chat/:admin_id/', admin_ws.AdminWs),
    # path('ws/cons_chat/:cons_id/', consumers.ChatConsumer),
    url(r'^ws/admin_chat/(?P<admin_id>[^/]+)/$', admin_ws.AdminWs),
    url(r'^ws/cons_chat/(?P<cons_id>[^/]+)/$', consumers.ChatConsumer),
    # url(r'^ws/chat/(?P<room_name>[^/]+)/$', consumers.ChatConsumer),
]

注：服务器上要用：supervisor 和 asgi来部署。为了避免mysql链接失效：

from django.db import close_old_connections 

# 自己定义一个decorator，用来装饰使用数据库的函数
def close_old_connections_wrapper(func):
    def wrapper(*args, **kwargs):
        close_old_connections()
        return func(*args, **kwargs)

    return wrapper

可在connect函数中调用   close_old_connections