[Solved] Identify the error in this Flask-SocketIO event handler:@socketio.on('update') def handle_update(): data = request.json send(data) | Flask

Flask - WebSocket and Real-Time

Identify the error in this Flask-SocketIO event handler:

@socketio.on('update')
def handle_update():
    data = request.json
    send(data)

AUsing request.json inside WebSocket handler causes an error.

BMissing event name in @socketio.on decorator.

Csend() cannot send JSON data.

DFunction must have a parameter to receive message data.

Step-by-Step Solution

Solution:

Step 1: Understand request context in WebSocket
WebSocket handlers do not have HTTP request context, so request.json is not available and causes an error.
Step 2: Check other parts
The decorator has event name, send() can send JSON, and function can have zero parameters if no message expected.
Final Answer:
Using request.json inside WebSocket handler causes an error. -> Option A
Quick Check:
request.json not available in WebSocket handlers [OK]

Quick Trick: Don't use request.json in WebSocket handlers [OK]

Common Mistakes:

MISTAKES

Master "WebSocket and Real-Time" in Flask

9 interactive learning modes - each teaches the same concept differently

More Flask Quizzes

Identify the error in this Flask-SocketIO event handler: