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Flask-socketio, send message only to one chat

I am developing flask app with chat feature. When somenone sends message, it saves into db. Now I want to display it on screen with socketio but when someone sends message, it shows in every currently used chat. Does anyone know how to display message only in one correct chat? Every two users have own chat with ID or can create it by sending message.

main.py code:

 @app.route('/chat/<int:id>', methods=['GET', 'POST'])
    @login_required
    def chat(id):
        chat = Chats.query.get_or_404(id)
        form = MessageForm()
        messages = chat.messages
        chat_id = chat.id
        if current_user.id == chat.first_user or current_user.id == chat.second_user:
            if request.method == "POST":
                form1 = request.form.get("myMessage")
                chat_id = chat.id
                author = current_user.id
                message = Messages(author=author, chat=chat_id, content=form1)
                chat.last_message = datetime.utcnow()
                db.session.add(message)
                db.session.commit()
            return render_template('chat.html', chat=chat, messages=messages, form=form, chat_id = chat_id)
        else:
            return redirect(url_for('index'))


@socketio.on('message')
def handleMessage(msg):
    print('Message: ' + msg)
    send(msg, broadcast=True)

chat.html code:

<script type="text/javascript">
    $(document).ready(function() {
    
        var socket = io.connect('http://127.0.0.1:5000');
    
        socket.on('connect', function() {
            socket.send('User has connected!');
        });
    
        socket.on('message', function(msg) {
            $("#messages").append('<li>'+msg+'</li>');
            console.log('Received message');
        });
    
        $('#sendbutton').on('click', function() {
            socket.send($('#myMessage').val());
            $('#myMessage').val('');
        });
    
    });
    </script>
    <ul id="messages"></ul>
    <input type="text" id="myMessage">
    <button id="sendbutton">Send</button>
  
about 4 years ago · Juan Pablo Isaza
1 answers
Answer question

0

I was just struggling with this issue. Using the 'to' argument in emit() worked for me. This also works for the send() function. https://flask-socketio.readthedocs.io/en/latest/getting_started.html#:~:text=For%20many%20applications,the%20to%20argument.

Update

For added clarity, use Flask-SocketIO's rooms and use "to" argument (see documentation). Assuming that chat_id is the room, try:

chat.html

<script type="text/javascript">
    $(document).ready(function() {
    
        var socket = io.connect('http://127.0.0.1:5000');
    
        socket.on('connect', function() {
            socket.send('join_room', {
                name: "{{ user }}",
                room: "{{ chat_id }}"
            })
        });
    
        socket.on('receive_message', function(data) {
            $("#messages").append('<li>'+data.msg+'</li>');
            console.log('Received message');
        });
    
        $('#sendbutton').on('click', function() {
            var msg = $('#myMessage').val();
            socket.send('send_message', {
                msg: msg,
                room: "{{ chat_id }}"
            })
            $('#myMessage').val('');
        });

        window.onbeforeunload = function(data) {
        socket.emit('leave_room', {
            name: "{{ user }}",
            room: "{{ chat_id }}"
        })
    };
    
    });
    </script>
    <ul id="messages"></ul>
    <input type="text" id="myMessage">
    <button id="sendbutton">Send</button>

main.py

@app.route('/chat/<int:id>', methods=['GET', 'POST'])
    @login_required
    def chat(id):
        chat = Chats.query.get_or_404(id)
        form = MessageForm()
        messages = chat.messages
        chat_id = chat.id
        user = current_user.id
        if current_user.id == chat.first_user or current_user.id == chat.second_user:
            if request.method == "POST":
                form1 = request.form.get("myMessage")
                chat_id = chat.id
                author = current_user.id
                message = Messages(author=author, chat=chat_id, content=form1)
                chat.last_message = datetime.utcnow()
                db.session.add(message)
                db.session.commit()
            return render_template('chat.html', chat=chat, messages=messages, form=form, chat_id = chat_id, user=user)
        else:
            return redirect(url_for('index'))

@socketio.on('join_room')
def handle_join_room_event(data):
    name = data['name']
    room = data['room']
    join_room(room)
    socketio.send(name + 'has connected!', to=room)

@socketio.on('send_message')
def sendMessage(data):
    room = data['room']
    send('receive_message', data, to=room)

@socketio.on('leave_room')
def handle_join_room_event(data):
    name = data['name']
    room = data['room']
    leave_room(room)
    socketio.send(name + 'has disconnected', to=room)
about 4 years ago · Juan Pablo Isaza Report
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