I am making a chat application using flask-socketio and now I want to emit a message to server with client's username when a client gets disconnected i.e. when client closes browser/tab so that I can emit that message from server to all existing clients for them to change their online friends list. I have googled for more than two hours and anything I have come close to is this and this but it doesn't work for me. I got a way in flask-socketio docs by the following way in server side but I don't know which client got disconnected so I could not change the online friends list.
@socketio.on('disconnect')
def test_disconnect():
print('Client disconnected')
emit('client disconnected','a client disconnected but I dont know who',broadcast = True) # i have imported emit
# but since i don't know which client disconnected i couldn't emit client name above.
So, I think it would be better to send message from client side like following but after that client closes browser,server does not get that message:
// handle disconnect
socket.on('disconnect',()=>{
socket.emit('client disconnected',{'username':localStorage.getItem('username')})
})
I am new to flask-socketio and any help would be highly appreciated.
You can make use of onbeforeunload event. This event gets fired, when a browser tab or a window is closing, trying navigate away from the page or reloading the page.
Client side:
<script>
window.onbeforeunload = function () {
socket.emit('client_disconnecting', {'username':localStorage.getItem('username')});
}
</script>
Server side:
@socket.on('client_disconnecting')
def disconnect_details(data):
print(f'{data['username']} user disconnected.')