[Solved] What will be the output behavior when this Flask-SocketIO code runs?from flask_socketio import SocketIO, join_room, emit @socketio.on('join') def on_join(data):... | Flask

Flask - WebSocket and Real-Time

What will be the output behavior when this Flask-SocketIO code runs?

from flask_socketio import SocketIO, join_room, emit

@socketio.on('join')
def on_join(data):
    room = data['room']
    join_room(room)
    emit('message', f'User joined {room}', room=room)

ANo message is sent because emit is missing event name

BAll clients in the specified room receive 'User joined {room}' message

COnly the joining client receives the message

DAn error occurs because join_room requires a user argument

Step-by-Step Solution

Solution:

Step 1: Analyze the join_room call
The user is added to the room specified by data['room'].
Step 2: Check the emit call with room parameter
emit sends the message to all clients in that room.
Final Answer:
All clients in the specified room receive 'User joined {room}' message -> Option B
Quick Check:
emit with room= sends to all in room [OK]

Quick Trick: emit with room= sends to all clients in that room [OK]

Common Mistakes:

MISTAKES

Thinking only the joining client gets the message
Believing emit lacks event name (it has 'message')
Assuming join_room needs a user argument

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What will be the output behavior when this Flask-SocketIO code runs?

Step 1: Analyze the join_room call

Step 2: Check the emit call with room parameter

Final Answer:

Quick Check:

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