Django ReconnectingWebSocket 使用

ReconnectingWebSocket

ReconnectingWebSocket 是一个小型的 JavaScript 库，封装了 WebSocket API ，用它可以实现服务器向客户端推送数据。避免了客户端频繁发起请求。
Django是建立在请求和响应的简单概念之上的：浏览器发出请求，Django调用一个视图，它返回一个响应并发送回浏览器，这就完成了一次请求。
Django Channels：取代了Django中的“guts” ——请求/响应周期发送跨通道的消息。Channels允许Django以非常类似于传统HTTP的方式支持WebSockets。Channels也允许在运行Django的服务器上运行后台任务。HTTP请求表现以前一样,但也通过Channels进行路由。
JS代码

 var ws_scheme = window.location.protocol == "https:" ? "wss" : "ws";
        var ws_path = ws_scheme + '://' + window.location.host + "/message/" + "{{ user.UserID  }}/" + "stream/";
        console.log("Connecting to " + ws_path);
        var socket = new ReconnectingWebSocket(ws_path);

        // Handle incoming messages
        socket.onmessage = function (message) {
            // 处理服务器推送过来的数据

        };

        // Helpful debugging
        socket.onopen = function () {
             //链接打开
            console.log("Connected to notification socket");
        }
        socket.onclose = function () {
            //链接关闭
            console.log("Disconnected to notification socket");
        }

Django 服务端代码

#setting配置
CHANNEL_LAYERS = {
    "default": {
        # This example app uses the Redis channel layer implementation asgi_redis
        "BACKEND": "asgi_redis.RedisChannelLayer",
        "CONFIG": {
            "hosts": [(redis_host, 6379)],
        },
        "ROUTING": "channel_routing",#路由名字
    },
}

#路由
channel_routing = [
    # Called when incoming WebSockets connect 连接上
    route("websocket.connect", connect_blog, path=r'^/message/(?P<slug>[^/]+)/stream/$'),

    # Called when the client closes the socket 断开
    route("websocket.disconnect", disconnect_blog, path=r'^/message/(?P<slug>[^/]+)/stream/$'),
]

def connect_blog(message, slug):#链接上来的方法
    Group(liveblog.group_name).add(message.reply_channel)
def disconnect_blog(message, slug):#断开的方法
    Group(liveblog.group_name).discard(message.reply_channel)

#发送的时候直接再Group组里面找到对应的message.reply_channel，然后send出去
 Group(blog.group_name).send({
                    # WebSocket text frame, with JSON content
                    "text": json.dumps(notification),
                })