2019年1月7日

python 簡易 websocket server

Websocket Server 是一個簡單的 websocket server,沒有任何其他的關聯的套件,只需要 python 標準的 sdk。

由 github 下載原始檔 zip 後,將 server.py 以及 websocket_server 目錄複製到 project 裡面。

在 server.py 的 message_received 加上一行廣播訊息的程式碼。

server.py

from websocket_server import WebsocketServer

# Called for every client connecting (after handshake)
def new_client(client, server):
    print("New client connected and was given id %d" % client['id'])
    server.send_message_to_all("Hey all, a new client has joined us")


# Called for every client disconnecting
def client_left(client, server):
    print("Client(%d) disconnected" % client['id'])


# Called when a client sends a message
def message_received(client, server, message):
    if len(message) > 200:
        message = message[:200]+'..'
    print("Client(%d) said: %s" % (client['id'], message))
    server.send_message_to_all("Client(%d) said: %s" % (client['id'], message))


PORT=9001
server = WebsocketServer(PORT)
server.set_fn_new_client(new_client)
server.set_fn_client_left(client_left)
server.set_fn_message_received(message_received)
server.run_forever()

另外製作一個 client.html

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>html5 websocket特性</title>
        <style>
            body{
                overflow: hidden;
            }
            h2{
                margin-top: 30px;
                text-align: center;
                background-color: #393D49;
                color: #fff;
                ont-weight: normal;
            padding: 15px 0
            }
            #chat{
                text-align: center;
            }
            #win{
                margin-top: 20px;
                text-align: center;
            }
            #sse{
                margin-top: 10px;
                text-align: center;
            }
            #sse button{
                background-color: #009688;
                color: #fff;
                height: 40px;
                border: 0;
                border-radius: 3px 3px;
                padding-left: 10px;
                padding-right: 10px;
                cursor: pointer;
            }
        </style>
        <script src="http://code.jquery.com/jquery-1.12.4.min.js"></script>
    </head>
    <body>
        <h2>聊天室</h2>
            <div id="chat">
                <textarea id="history" cols="80" rows="20"></textarea>
            </div>

            <div id="win">
                <textarea id="messagewin" cols="80" rows="5"></textarea>
            </div>

            <div id="sse">
                <button onclick="sendMessage()">傳送對話</button>
            </div>

        <script type="text/javascript">
            var oHistory = $('#history');
            var oWin = $('#messagewin');

            if ("WebSocket" in window){
                console.log("您的瀏覽器支援 WebSocket!");
                var ws = new WebSocket("ws://127.0.0.1:9001");
                //var ws = new WebSocket("ws://localhost:9001");
                ws.onopen = function(){
                    console.log("websocket 已連線上");
                }

                ws.onmessage = function (evt) {
                    var dataReceive = evt.data;
                    console.log("資料已接收..."+dataReceive);
                    $('#history').val($('#history').val()+dataReceive+"\n");
                };

                ws.onclose = function() {
                    console.log("連線已關閉...");
                };

            }else{
                // 瀏覽器不支援 WebSocket
                console.log("您的瀏覽器不支援 WebSocket!");
            }

            function sendMessage(){
                var dataSend = oWin.val().trim();
                ws.send(dataSend);
                oWin.val('');
            }
        </script>
    </body>
</html>

將 client.html 放在任意一個 webserver 上,因為 client.html 會連接到 127.0.0.1 的 websocket server,以 python server.py 啟動 server 後,打開兩個 browser tab,打開 client.html

兩個視窗間,因為剛剛增加的那一行廣播訊息的 code,所以可以看到所有訊息。

References

python與html5 websocket開發聊天對話窗