Broadcasting to clients in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Flask-SocketIO extension.

Flask

from flask_socketio import [1]

Drag options to blanks, or click blank then click option'

ASocketIO

BFlaskSocket

CSocket

DFlaskIO

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect class names like FlaskSocket or FlaskIO.

Trying to import Socket instead of SocketIO.

The Flask-SocketIO extension is imported using SocketIO.

2fill in blank

medium

Complete the code to initialize SocketIO with the Flask app.

Flask

app = Flask(__name__)
socketio = [1](app)

Drag options to blanks, or click blank then click option'

ASocketIO

BSocket

CFlaskSocketIO

DSocketServer

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect class names like Socket or SocketServer.

Not passing the Flask app instance to the SocketIO constructor.

We initialize SocketIO by passing the Flask app instance to SocketIO.

3fill in blank

hard

Fix the error in the event handler to broadcast a message to all clients.

Flask

@socketio.on('message')
def handle_message(msg):
    socketio.emit('message', msg, [1]=True)

Drag options to blanks, or click blank then click option'

Asend

Bbroadcasting

Csend_all

Dbroadcast

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect argument names like broadcasting or send_all.

Omitting the broadcast argument and sending only to the sender.

To send a message to all connected clients, use the broadcast=True argument in emit.

4fill in blank

hard

Fill both blanks to emit a custom event to all clients except the sender.

Flask

@socketio.on('chat')
def handle_chat(data):
    socketio.emit([1], data, [2]=True)

Drag options to blanks, or click blank then click option'

A'chat_response'

B'chat_message'

Cbroadcast

Dinclude_self

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong event names like 'chat_response'.

Using include_self instead of broadcast.

The event name is 'chat_message'. To emit to all clients except the sender, set broadcast=True.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that broadcasts only messages longer than 5 characters.

Flask

messages = {user: msg for user, msg in data.items() if len(msg) [1] [2]
socketio.emit('filtered', messages, [3]=True)

Drag options to blanks, or click blank then click option'

A>

B5

Cbroadcast

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using less than operator instead of greater than.

Forgetting to set broadcast=True in emit.

The comprehension filters messages with length greater than 5 using len(msg) > 5. The emit uses broadcast=True to send to all clients.