Flask-SocketIO setup - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Flask-SocketIO used for?

Flask-SocketIO allows real-time communication between the client and server using WebSockets, enabling instant updates without refreshing the page.

beginner

Which Python package do you install to use Flask-SocketIO?

You install the package named flask-socketio using pip.

beginner

How do you initialize Flask-SocketIO in a Flask app?

Import <code>SocketIO</code> from <code>flask_socketio</code> and create an instance by passing the Flask app: <br><code>socketio = SocketIO(app)</code>

beginner

What method do you use to run the Flask app with SocketIO support?

Instead of app.run(), use socketio.run(app) to enable WebSocket handling.

intermediate

How do you listen for a custom event from the client in Flask-SocketIO?

Use the @socketio.on('event_name') decorator on a function to handle that event.

Which command installs Flask-SocketIO?

A pip install flask-socketio

B pip install flask_socketio

C pip install socketio-flask

D pip install flaskwebsocket

The correct package name is flask-socketio.

How do you create a SocketIO instance in Flask?

A socketio = SocketIO(server)

B socketio = SocketIO()

C socketio = SocketIO(flask)

D socketio = SocketIO(app)

You pass the Flask app instance to SocketIO when creating it.

Which method runs the Flask app with SocketIO support?

A app.run()

B socketio.start(app)

C socketio.run(app)

D app.start()

Use socketio.run(app) to enable WebSocket handling.

What decorator listens for a client event named 'message'?

A @app.route('message')

B @socketio.on('message')

C @socketio.event('message')

D @app.on('message')

Use @socketio.on('message') to handle the 'message' event.

What protocol does Flask-SocketIO primarily use for real-time communication?

A WebSocket

B FTP

C SMTP

D HTTP

Flask-SocketIO uses WebSocket protocol for real-time communication.

Explain the steps to set up Flask-SocketIO in a new Flask project.

Think about installation, imports, initialization, and running the app.

Describe how you handle a custom event sent from the client using Flask-SocketIO.

Focus on event listening and response.