Flask-SocketIO using emit outside decorator doesn't work

Question

I have a listener function that would be called every time a value changes, and I want socketio to emit this new value.

This is what I've come up at last but it still hasn't worked out. Why doesn't socketio.emit work outside of context when it should? If it doesn't, how to emit within a listener function?

socketio in decorator vs view:

@socketio.on('my event')
def connected(json):
    join_room(room = current_user.id)
    leave_room(room=rooms()[0]) # leave previous room
    print(rooms(), flush=True)
    socketio.emit('echo', 'hi', room=current_user.id) # this works fine

@app.route('/')
def home():
    socketio.emit('echo', 'hi2', room=current_user.id) # this does not
    return render_template("home.html", session = session)

my listener function inside a view:

def someotherview():
    itemList = [a,b,c]
    @copy_current_request_context
    def listener(event):
        item = str(event)
        if item in itemList:
            print(item, event, flush=True) # this prints
            socketio.emit('echo', 'test', room=current_user.id) # this also doesnt do anything

Console log from website: only 'hi', no 'hi2' which indicates the prior statement.