pip 
                          
                            install
                          
                           eventlet==
                          
                            0.33
                          
                          .
                          
                            3
                          
                          
                            
pip 
                          
                          
                            install
                          
                           flask-socketio==
                          
                            5.8
                          
                          .
                          
                            0
                          
                          
                            
pip 
                          
                          
                            install
                          
                           flask==
                          
                            1.1
                          
                          .
                          
                            4
                          
                        

                          
                            from
                          
                           threading 
                          
                            import
                          
                          
                             Lock

                          
                          
                            from
                          
                           flask 
                          
                            import
                          
                          
                             Flask, render_template, session, request, copy_current_request_context

                          
                          
                            from
                          
                           flask_socketio 
                          
                            import
                          
                          
                             SocketIO, emit, join_room, leave_room, close_room, rooms, disconnect


                          
                          
                            #
                          
                          
                             Set this variable to "threading", "eventlet" or "gevent" to test the
                          
                          
                            
#
                          
                          
                             different async modes, or leave it set to None for the application to choose
                          
                          
                            
#
                          
                          
                             the best option based on installed packages.
                          
                          
async_mode =
                          
                             None

app 
                          
                          = Flask(
                          
                            __name__
                          
                          
                            )
app.config[
                          
                          
                            '
                          
                          
                            SECRET_KEY
                          
                          
                            '
                          
                          ] = 
                          
                            '
                          
                          
                            secret!
                          
                          
                            '
                          
                          
                            
socketio 
                          
                          = SocketIO(app, async_mode=
                          
                            async_mode)
thread 
                          
                          =
                          
                             None
thread_lock 
                          
                          =
                          
                             Lock()



                          
                          
                            def
                          
                          
                             background_thread():
    
                          
                          
                            """
                          
                          
                            Example of how to send server generated events to clients.
                          
                          
                            """
                          
                          
                            
    count 
                          
                          =
                          
                             0
    
                          
                          
                            while
                          
                          
                             True:
        socketio.sleep(
                          
                          10
                          
                            )
        count 
                          
                          += 1
                          
                            
        socketio.emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
                      {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : 
                          
                            '
                          
                          
                            Server generated event
                          
                          
                            '
                          
                          , 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          
                            : count})


@app.route(
                          
                          
                            '
                          
                          
                            /
                          
                          
                            '
                          
                          
                            )

                          
                          
                            def
                          
                          
                             index():
    
                          
                          
                            return
                          
                           render_template(
                          
                            '
                          
                          
                            index.html
                          
                          
                            '
                          
                          , async_mode=
                          
                            socketio.async_mode)


@socketio.event

                          
                          
                            def
                          
                          
                             my_event(message):
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
                          
                            
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
         {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : message[
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          ], 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          
                            ]})


@socketio.event

                          
                          
                            def
                          
                          
                             my_broadcast_event(message):
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
                          
                            
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
         {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : message[
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          ], 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          
                            ]},
         broadcast
                          
                          =
                          
                            True)


@socketio.event

                          
                          
                            def
                          
                          
                             join(message):
    join_room(message[
                          
                          
                            '
                          
                          
                            room
                          
                          
                            '
                          
                          
                            ])
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
                          
                            
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
         {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : 
                          
                            '
                          
                          
                            In rooms: 
                          
                          
                            '
                          
                           + 
                          
                            '
                          
                          
                            , 
                          
                          
                            '
                          
                          
                            .join(rooms()),
          
                          
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          
                            ]})


@socketio.event

                          
                          
                            def
                          
                          
                             leave(message):
    leave_room(message[
                          
                          
                            '
                          
                          
                            room
                          
                          
                            '
                          
                          
                            ])
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
                          
                            
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
         {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : 
                          
                            '
                          
                          
                            In rooms: 
                          
                          
                            '
                          
                           + 
                          
                            '
                          
                          
                            , 
                          
                          
                            '
                          
                          
                            .join(rooms()),
          
                          
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          
                            ]})


@socketio.on(
                          
                          
                            '
                          
                          
                            close_room
                          
                          
                            '
                          
                          
                            )

                          
                          
                            def
                          
                          
                             on_close_room(message):
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
                          
                            
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          , {
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : 
                          
                            '
                          
                          
                            Room 
                          
                          
                            '
                          
                           + message[
                          
                            '
                          
                          
                            room
                          
                          
                            '
                          
                          ] + 
                          
                            '
                          
                          
                             is closing.
                          
                          
                            '
                          
                          
                            ,
                         
                          
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          
                            ]},
         to
                          
                          =message[
                          
                            '
                          
                          
                            room
                          
                          
                            '
                          
                          
                            ])
    close_room(message[
                          
                          
                            '
                          
                          
                            room
                          
                          
                            '
                          
                          
                            ])


@socketio.event

                          
                          
                            def
                          
                          
                             my_room_event(message):
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
                          
                            
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
         {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : message[
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          ], 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          
                            ]},
         to
                          
                          =message[
                          
                            '
                          
                          
                            room
                          
                          
                            '
                          
                          
                            ])


@socketio.event

                          
                          
                            def
                          
                          
                             disconnect_request():
    @copy_current_request_context
    
                          
                          
                            def
                          
                          
                             can_disconnect():
        disconnect()
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
    
                          
                            #
                          
                          
                             for this emit we use a callback function
                          
                          
                            #
                          
                          
                             when the callback function is invoked we know that the message has been
                          
                          
                            #
                          
                          
                             received and it is safe to disconnect
                          
                          
    emit(
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
         {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : 
                          
                            '
                          
                          
                            Disconnected!
                          
                          
                            '
                          
                          , 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          
                            ]},
         callback
                          
                          =
                          
                            can_disconnect)


@socketio.event

                          
                          
                            def
                          
                          
                             my_ping():
    emit(
                          
                          
                            '
                          
                          
                            my_pong
                          
                          
                            '
                          
                          
                            )


@socketio.event

                          
                          
                            def
                          
                          
                             connect():
    
                          
                          
                            global
                          
                          
                             thread
    with thread_lock:
        
                          
                          
                            if
                          
                           thread 
                          
                            is
                          
                          
                             None:
            thread 
                          
                          =
                          
                             socketio.start_background_task(background_thread)
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          , {
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : 
                          
                            '
                          
                          
                            Connected
                          
                          
                            '
                          
                          , 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          
                            : 0})


@socketio.on(
                          
                          
                            '
                          
                          
                            disconnect
                          
                          
                            '
                          
                          
                            )

                          
                          
                            def
                          
                          
                             test_disconnect():
    
                          
                          
                            print
                          
                          (
                          
                            '
                          
                          
                            Client disconnected
                          
                          
                            '
                          
                          
                            , request.sid)



                          
                          
                            if
                          
                          
                            __name__
                          
                           == 
                          
                            '
                          
                          
                            __main__
                          
                          
                            '
                          
                          
                            :
    socketio.run(app, host
                          
                          =
                          
                            '
                          
                          
                            0.0.0.0
                          
                          
                            '
                          
                          , debug=True)
                        

                          
                            <!
                          
                          
                            DOCTYPE HTML
                          
                          
                            >
                          
                          
                            <
                          
                          
                            html
                          
                          
                            >
                          
                          
                            <
                          
                          
                            head
                          
                          
                            >
                          
                          
                            <
                          
                          
                            title
                          
                          
                            >
                          
                          Flask-SocketIO Test
                          
                            </
                          
                          
                            title
                          
                          
                            >
                          
                          
                            <
                          
                          
                            script 
                          
                          
                            src
                          
                          
                            ="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js"
                          
                          
                             integrity
                          
                          
                            ="sha512-bLT0Qm9VnAYZDflyKcBaQ2gg0hSYNQrJ8RilYldYQ1FxQYoCLtUjuuRuZo+fjqhx/qtq/1itJ0C2ejDxltZVFg=="
                          
                          
                             crossorigin
                          
                          
                            ="anonymous"
                          
                          
                            ></
                          
                          
                            script
                          
                          
                            >
                          
                          
                            <
                          
                          
                            script 
                          
                          
                            src
                          
                          
                            ="https://cdnjs.cloudflare.com/ajax/libs/socket.io/3.0.4/socket.io.js"
                          
                          
                             integrity
                          
                          
                            ="sha512-aMGMvNYu8Ue4G+fHa359jcPb1u+ytAF+P2SCb+PxrjCdO3n3ZTxJ30zuH39rimUggmTwmh2u7wvQsDTHESnmfQ=="
                          
                          
                             crossorigin
                          
                          
                            ="anonymous"
                          
                          
                            ></
                          
                          
                            script
                          
                          
                            >
                          
                          
                            <
                          
                          
                            script 
                          
                          
                            type
                          
                          
                            ="text/javascript"
                          
                          
                             charset
                          
                          
                            ="utf-8"
                          
                          
                            >
                          
                          
                            
        $(document).ready(
                          
                          
                            function
                          
                          
                            () {
            
                          
                          
                            //
                          
                          
                             Connect to the Socket.IO server.
                          
                          
                            //
                          
                          
                             The connection URL has the following format, relative to the current page:
                          
                          
                            //
                          
                          
                                 http[s]://<domain>:<port>[/<namespace>]
                          
                          
                            var
                          
                          
                             socket 
                          
                          
                            =
                          
                          
                             io.connect(
                          
                          
                            '
                          
                          
                            http://
                          
                          
                            '
                          
                          
                            +
                          
                          
                             document.domain 
                          
                          
                            +
                          
                          
                            '
                          
                          
                            :
                          
                          
                            '
                          
                          
                            +
                          
                          
                             location.port);

            
                          
                          
                            //
                          
                          
                             Event handler for new connections.
                          
                          
                            //
                          
                          
                             The callback function is invoked when a connection with the
                          
                          
                            //
                          
                          
                             server is established.
                          
                          
                                        socket.on(
                          
                          
                            '
                          
                          
                            connect
                          
                          
                            '
                          
                          
                            , 
                          
                          
                            function
                          
                          
                            () {
                socket.emit(
                          
                          
                            '
                          
                          
                            my_event
                          
                          
                            '
                          
                          
                            , {data: 
                          
                          
                            '
                          
                          
                            I\'m connected!
                          
                          
                            '
                          
                          
                            });
            });

            
                          
                          
                            //
                          
                          
                             Event handler for server sent data.
                          
                          
                            //
                          
                          
                             The callback function is invoked whenever the server emits data
                          
                          
                            //
                          
                          
                             to the client. The data is then displayed in the "Received"
                          
                          
                            //
                          
                          
                             section of the page.
                          
                          
                                        socket.on(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            , 
                          
                          
                            function
                          
                          
                            (msg, cb) {
                $(
                          
                          
                            '
                          
                          
                            #log
                          
                          
                            '
                          
                          
                            ).append(
                          
                          
                            '
                          
                          
                            <br>
                          
                          
                            '
                          
                          
                            +
                          
                          
                             $(
                          
                          
                            '
                          
                          
                            <div/>
                          
                          
                            '
                          
                          
                            ).text(
                          
                          
                            '
                          
                          
                            Received #
                          
                          
                            '
                          
                          
                            +
                          
                          
                             msg.count 
                          
                          
                            +
                          
                          
                            '
                          
                          
                            : 
                          
                          
                            '
                          
                          
                            +
                          
                          
                             msg.data).html());
                
                          
                          
                            if
                          
                          
                             (cb)
                    cb();
            });

            
                          
                          
                            //
                          
                          
                             Interval function that tests message latency by sending a "ping"
                          
                          
                            //
                          
                          
                             message. The server then responds with a "pong" message and the
                          
                          
                            //
                          
                          
                             round trip time is measured.
                          
                          
                            var
                          
                          
                             ping_pong_times 
                          
                          
                            =
                          
                          
                             [];
            
                          
                          
                            var
                          
                          
                             start_time;
            window.setInterval(
                          
                          
                            function
                          
                          
                            () {
                start_time 
                          
                          
                            =
                          
                          
                             (
                          
                          
                            new
                          
                          
                             Date).getTime();
                $(
                          
                          
                            '
                          
                          
                            #transport
                          
                          
                            '
                          
                          
                            ).text(socket.io.engine.transport.name);
                socket.emit(
                          
                          
                            '
                          
                          
                            my_ping
                          
                          
                            '
                          
                          
                            );
            }, 
                          
                          
                            1000
                          
                          
                            );

            
                          
                          
                            //
                          
                          
                             Handler for the "pong" message. When the pong is received, the
                          
                          
                            //
                          
                          
                             time from the ping is stored, and the average of the last 30
                          
                          
                            //
                          
                          
                             samples is average and displayed.
                          
                          
                                        socket.on(
                          
                          
                            '
                          
                          
                            my_pong
                          
                          
                            '
                          
                          
                            , 
                          
                          
                            function
                          
                          
                            () {
                
                          
                          
                            var
                          
                          
                             latency 
                          
                          
                            =
                          
                          
                             (
                          
                          
                            new
                          
                          
                             Date).getTime() 
                          
                          
                            -
                          
                          
                             start_time;
                ping_pong_times.push(latency);
                ping_pong_times 
                          
                          
                            =
                          
                          
                             ping_pong_times.slice(
                          
                          
                            -
                          
                          
                            30
                          
                          
                            ); 
                          
                          
                            //
                          
                          
                             keep last 30 samples
                          
                          
                            var
                          
                          
                             sum 
                          
                          
                            =
                          
                          
                            0
                          
                          
                            ;
                
                          
                          
                            for
                          
                          
                             (
                          
                          
                            var
                          
                          
                             i 
                          
                          
                            =
                          
                          
                            0
                          
                          
                            ; i 
                          
                          
                            <
                          
                          
                             ping_pong_times.length; i
                          
                          
                            ++
                          
                          
                            )
                    sum 
                          
                          
                            +=
                          
                          
                             ping_pong_times[i];
                $(
                          
                          
                            '
                          
                          
                            #ping-pong
                          
                          
                            '
                          
                          
                            ).text(Math.round(
                          
                          
                            10
                          
                          
                            *
                          
                          
                             sum 
                          
                          
                            /
                          
                          
                             ping_pong_times.length) 
                          
                          
                            /
                          
                          
                            10
                          
                          
                            );
            });

            
                          
                          
                            //
                          
                          
                             Handlers for the different forms in the page.
                          
                          
                            //
                          
                          
                             These accept data from the user and send it to the server in a
                          
                          
                            //
                          
                          
                             variety of ways
                          
                          
                                        $(
                          
                          
                            '
                          
                          
                            form#emit
                          
                          
                            '
                          
                          
                            ).submit(
                          
                          
                            function
                          
                          
                            (event) {
                socket.emit(
                          
                          
                            '
                          
                          
                            my_event
                          
                          
                            '
                          
                          
                            , {data: $(
                          
                          
                            '
                          
                          
                            #emit_data
                          
                          
                            '
                          
                          
                            ).val()});
                
                          
                          
                            return
                          
                          
                            false
                          
                          
                            ;
            });
            $(
                          
                          
                            '
                          
                          
                            form#broadcast
                          
                          
                            '
                          
                          
                            ).submit(
                          
                          
                            function
                          
                          
                            (event) {
                socket.emit(
                          
                          
                            '
                          
                          
                            my_broadcast_event
                          
                          
                            '
                          
                          
                            , {data: $(
                          
                          
                            '
                          
                          
                            #broadcast_data
                          
                          
                            '
                          
                          
                            ).val()});
                
                          
                          
                            return
                          
                          
                            false
                          
                          
                            ;
            });
            $(
                          
                          
                            '
                          
                          
                            form#join
                          
                          
                            '
                          
                          
                            ).submit(
                          
                          
                            function
                          
                          
                            (event) {
                socket.emit(
                          
                          
                            '
                          
                          
                            join
                          
                          
                            '
                          
                          
                            , {room: $(
                          
                          
                            '
                          
                          
                            #join_room
                          
                          
                            '
                          
                          
                            ).val()});
                
                          
                          
                            return
                          
                          
                            false
                          
                          
                            ;
            });
            $(
                          
                          
                            '
                          
                          
                            form#leave
                          
                          
                            '
                          
                          
                            ).submit(
                          
                          
                            function
                          
                          
                            (event) {
                socket.emit(
                          
                          
                            '
                          
                          
                            leave
                          
                          
                            '
                          
                          
                            , {room: $(
                          
                          
                            '
                          
                          
                            #leave_room
                          
                          
                            '
                          
                          
                            ).val()});
                
                          
                          
                            return
                          
                          
                            false
                          
                          
                            ;
            });
            $(
                          
                          
                            '
                          
                          
                            form#send_room
                          
                          
                            '
                          
                          
                            ).submit(
                          
                          
                            function
                          
                          
                            (event) {
                socket.emit(
                          
                          
                            '
                          
                          
                            my_room_event
                          
                          
                            '
                          
                          
                            , {room: $(
                          
                          
                            '
                          
                          
                            #room_name
                          
                          
                            '
                          
                          
                            ).val(), data: $(
                          
                          
                            '
                          
                          
                            #room_data
                          
                          
                            '
                          
                          
                            ).val()});
                
                          
                          
                            return
                          
                          
                            false
                          
                          
                            ;
            });
            $(
                          
                          
                            '
                          
                          
                            form#close
                          
                          
                            '
                          
                          
                            ).submit(
                          
                          
                            function
                          
                          
                            (event) {
                socket.emit(
                          
                          
                            '
                          
                          
                            close_room
                          
                          
                            '
                          
                          
                            , {room: $(
                          
                          
                            '
                          
                          
                            #close_room
                          
                          
                            '
                          
                          
                            ).val()});
                
                          
                          
                            return
                          
                          
                            false
                          
                          
                            ;
            });
            $(
                          
                          
                            '
                          
                          
                            form#disconnect
                          
                          
                            '
                          
                          
                            ).submit(
                          
                          
                            function
                          
                          
                            (event) {
                socket.emit(
                          
                          
                            '
                          
                          
                            disconnect_request
                          
                          
                            '
                          
                          
                            );
                
                          
                          
                            return
                          
                          
                            false
                          
                          
                            ;
            });
        });
    
                          
                          
                            </
                          
                          
                            script
                          
                          
                            >
                          
                          
                            </
                          
                          
                            head
                          
                          
                            >
                          
                          
                            <
                          
                          
                            body
                          
                          
                            >
                          
                          
                            <
                          
                          
                            h1
                          
                          
                            >
                          
                          Flask-SocketIO Test
                          
                            </
                          
                          
                            h1
                          
                          
                            >
                          
                          
                            <
                          
                          
                            p
                          
                          
                            >
                          
                          
                            
      Async mode is: 
                          
                          
                            <
                          
                          
                            b
                          
                          
                            >
                          
                          {{ async_mode }}
                          
                            </
                          
                          
                            b
                          
                          
                            ><
                          
                          
                            br
                          
                          
                            >
                          
                          
                            
      Current transport is: 
                          
                          
                            <
                          
                          
                            b
                          
                          
                            ><
                          
                          
                            span 
                          
                          
                            id
                          
                          
                            ="transport"
                          
                          
                            ></
                          
                          
                            span
                          
                          
                            ></
                          
                          
                            b
                          
                          
                            ><
                          
                          
                            br
                          
                          
                            >
                          
                          
                            
      Average ping/pong latency: 
                          
                          
                            <
                          
                          
                            b
                          
                          
                            ><
                          
                          
                            span 
                          
                          
                            id
                          
                          
                            ="ping-pong"
                          
                          
                            ></
                          
                          
                            span
                          
                          
                            >
                          
                          ms
                          
                            </
                          
                          
                            b
                          
                          
                            >
                          
                          
                            </
                          
                          
                            p
                          
                          
                            >
                          
                          
                            <
                          
                          
                            h2
                          
                          
                            >
                          
                          Send:
                          
                            </
                          
                          
                            h2
                          
                          
                            >
                          
                          
                            <
                          
                          
                            form 
                          
                          
                            id
                          
                          
                            ="emit"
                          
                          
                             method
                          
                          
                            ="POST"
                          
                          
                             action
                          
                          
                            ='#'
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="text"
                          
                          
                             name
                          
                          
                            ="emit_data"
                          
                          
                             id
                          
                          
                            ="emit_data"
                          
                          
                             placeholder
                          
                          
                            ="Message"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="submit"
                          
                          
                             value
                          
                          
                            ="Echo"
                          
                          
                            >
                          
                          
                            </
                          
                          
                            form
                          
                          
                            >
                          
                          
                            <
                          
                          
                            form 
                          
                          
                            id
                          
                          
                            ="broadcast"
                          
                          
                             method
                          
                          
                            ="POST"
                          
                          
                             action
                          
                          
                            ='#'
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="text"
                          
                          
                             name
                          
                          
                            ="broadcast_data"
                          
                          
                             id
                          
                          
                            ="broadcast_data"
                          
                          
                             placeholder
                          
                          
                            ="Message"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="submit"
                          
                          
                             value
                          
                          
                            ="Broadcast"
                          
                          
                            >
                          
                          
                            </
                          
                          
                            form
                          
                          
                            >
                          
                          
                            <
                          
                          
                            form 
                          
                          
                            id
                          
                          
                            ="join"
                          
                          
                             method
                          
                          
                            ="POST"
                          
                          
                             action
                          
                          
                            ='#'
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="text"
                          
                          
                             name
                          
                          
                            ="join_room"
                          
                          
                             id
                          
                          
                            ="join_room"
                          
                          
                             placeholder
                          
                          
                            ="Room Name"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="submit"
                          
                          
                             value
                          
                          
                            ="Join Room"
                          
                          
                            >
                          
                          
                            </
                          
                          
                            form
                          
                          
                            >
                          
                          
                            <
                          
                          
                            form 
                          
                          
                            id
                          
                          
                            ="leave"
                          
                          
                             method
                          
                          
                            ="POST"
                          
                          
                             action
                          
                          
                            ='#'
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="text"
                          
                          
                             name
                          
                          
                            ="leave_room"
                          
                          
                             id
                          
                          
                            ="leave_room"
                          
                          
                             placeholder
                          
                          
                            ="Room Name"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="submit"
                          
                          
                             value
                          
                          
                            ="Leave Room"
                          
                          
                            >
                          
                          
                            </
                          
                          
                            form
                          
                          
                            >
                          
                          
                            <
                          
                          
                            form 
                          
                          
                            id
                          
                          
                            ="send_room"
                          
                          
                             method
                          
                          
                            ="POST"
                          
                          
                             action
                          
                          
                            ='#'
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="text"
                          
                          
                             name
                          
                          
                            ="room_name"
                          
                          
                             id
                          
                          
                            ="room_name"
                          
                          
                             placeholder
                          
                          
                            ="Room Name"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="text"
                          
                          
                             name
                          
                          
                            ="room_data"
                          
                          
                             id
                          
                          
                            ="room_data"
                          
                          
                             placeholder
                          
                          
                            ="Message"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="submit"
                          
                          
                             value
                          
                          
                            ="Send to Room"
                          
                          
                            >
                          
                          
                            </
                          
                          
                            form
                          
                          
                            >
                          
                          
                            <
                          
                          
                            form 
                          
                          
                            id
                          
                          
                            ="close"
                          
                          
                             method
                          
                          
                            ="POST"
                          
                          
                             action
                          
                          
                            ="#"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="text"
                          
                          
                             name
                          
                          
                            ="close_room"
                          
                          
                             id
                          
                          
                            ="close_room"
                          
                          
                             placeholder
                          
                          
                            ="Room Name"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="submit"
                          
                          
                             value
                          
                          
                            ="Close Room"
                          
                          
                            >
                          
                          
                            </
                          
                          
                            form
                          
                          
                            >
                          
                          
                            <
                          
                          
                            form 
                          
                          
                            id
                          
                          
                            ="disconnect"
                          
                          
                             method
                          
                          
                            ="POST"
                          
                          
                             action
                          
                          
                            ="#"
                          
                          
                            >
                          
                          
                            <
                          
                          
                            input 
                          
                          
                            type
                          
                          
                            ="submit"
                          
                          
                             value
                          
                          
                            ="Disconnect"
                          
                          
                            >
                          
                          
                            </
                          
                          
                            form
                          
                          
                            >
                          
                          
                            <
                          
                          
                            h2
                          
                          
                            >
                          
                          Receive:
                          
                            </
                          
                          
                            h2
                          
                          
                            >
                          
                          
                            <
                          
                          
                            div 
                          
                          
                            id
                          
                          
                            ="log"
                          
                          
                            ></
                          
                          
                            div
                          
                          
                            >
                          
                          
                            </
                          
                          
                            body
                          
                          
                            >
                          
                          
                            </
                          
                          
                            html
                          
                          
                            >
                          
                        

                          
                            　　var
                          
                           socket = io.connect('http://' + document.domain + ':' + location.port);
                        

                          
                            @socketio.event

                          
                          
                            def
                          
                          
                             connect():
    
                          
                          
                            global
                          
                          
                             thread
    with thread_lock:
        
                          
                          
                            if
                          
                           thread 
                          
                            is
                          
                          
                             None:
            thread 
                          
                          =
                          
                             socketio.start_background_task(background_thread)
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          , {
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : 
                          
                            '
                          
                          
                            Connected
                          
                          
                            '
                          
                          , 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : 0})
                        

                          socket.on('connect', 
                          
                            function
                          
                          
                            () {
                socket.emit(
                          
                          'my_event', {data: 'I\'m connected!'
                          
                            });
            });
                          
                        

                          socket.emit('my_event', {data: $('#emit_data').val()});
                        

                          
                            @socketio.event

                          
                          
                            def
                          
                          
                             my_event(message):
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
                          
                            
    emit(
                          
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
         {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : message[
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          ], 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ]})
                        

                          socket.on('my_response', 
                          
                            function
                          
                          
                            (msg, cb) {
                $(
                          
                          '#log').append('<br>' + $('<div/>').text('Received #' + msg.count + ': ' +
                          
                             msg.data).html());
                
                          
                          
                            if
                          
                          
                             (cb)
                    cb();
            });
                          
                        

                          
                            #
                          
                          
                             客户端
                          
                          
socket.emit(
                          
                            '
                          
                          
                            disconnect_request
                          
                          
                            '
                          
                          
                            );


                          
                          
                            #
                          
                          
                             服务端
                          
                          
                            
@socketio.event

                          
                          
                            def
                          
                          
                             disconnect_request():
    @copy_current_request_context
    
                          
                          
                            def
                          
                          
                             can_disconnect():
        disconnect()
    session[
                          
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          ] = session.get(
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          , 0) + 1
    
                          
                            #
                          
                          
                             for this emit we use a callback function
                          
                          
                            #
                          
                          
                             when the callback function is invoked we know that the message has been
                          
                          
                            #
                          
                          
                             received and it is safe to disconnect
                          
                          
    emit(
                          
                            '
                          
                          
                            my_response
                          
                          
                            '
                          
                          
                            ,
         {
                          
                          
                            '
                          
                          
                            data
                          
                          
                            '
                          
                          : 
                          
                            '
                          
                          
                            Disconnected!
                          
                          
                            '
                          
                          , 
                          
                            '
                          
                          
                            count
                          
                          
                            '
                          
                          : session[
                          
                            '
                          
                          
                            receive_count
                          
                          
                            '
                          
                          
                            ]},
         callback
                          
                          =can_disconnect)