[Solved] What is the main issue with this Flask-SocketIO event handler code? @socketio.on('message') def handle_message(): print('Message received') socketio.emit('response', {'data': 'OK'}) | Flask

Flask - WebSocket and Real-Time

What is the main issue with this Flask-SocketIO event handler code?

@socketio.on('message')
def handle_message():
    print('Message received')
    socketio.emit('response', {'data': 'OK'})

AThe print statement should be replaced with return

BThe event name 'message' is invalid in Flask-SocketIO

Csocketio.emit cannot be called inside an event handler

DThe handler function is missing a 'data' parameter to receive the event payload

Step-by-Step Solution

Solution:

Step 1: Check event handler signature
Flask-SocketIO event handlers must accept data if the event sends any.
Step 2: Identify missing parameter
The function lacks a parameter to receive incoming data.
Final Answer:
Missing 'data' parameter in handler function -> Option D
Quick Check:
Event handlers must match event payload signature. [OK]

Quick Trick: Event handlers need parameters matching event data [OK]

Common Mistakes:

MISTAKES

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What is the main issue with this Flask-SocketIO event handler code?