Challenge - 5 Problems

🎖️

Flash Mastery

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Test your skills under time pressure!

❓ component_behavior

intermediate

2:00remaining

How does Flask flash message display behave?

Consider a Flask app that flashes a message and redirects to a page that displays it. What will the user see after the redirect?

Flask

from flask import Flask, flash, redirect, url_for, render_template_string, get_flashed_messages

app = Flask(__name__)
app.secret_key = 'secret'

@app.route('/set')
def set_message():
    flash('Welcome back!')
    return redirect(url_for('show_message'))

@app.route('/show')
def show_message():
    messages = get_flashed_messages()
    return render_template_string('<ul>{% for msg in messages %}<li>{{ msg }}</li>{% endfor %}</ul>', messages=messages)

AThe page at /show will display nothing because flash messages are cleared immediately.

BThe page at /show will display a list with one item: 'Welcome back!'

CThe page at /show will show an error because get_flashed_messages() requires arguments.

DThe page at /show will display the message multiple times if refreshed.

Attempts:

2 left

📝 Syntax

intermediate

2:00remaining

Identify the syntax error in flashing a message

Which option contains a syntax error when trying to flash a message in Flask?

Flask

from flask import flash

# Flash a message example
flash('Error occurred', category='error')

Aflash('Error occurred', category='error')

Bflash('Error occurred', 'error')

Cflash(message='Error occurred', category='error')

Dflash('Error occurred', category=error)

Attempts:

2 left

❓ state_output

advanced

2:00remaining

What is the output after multiple flash calls before rendering?

If you flash multiple messages before rendering a template that shows them all, what will be displayed?

Flask

from flask import Flask, flash, render_template_string, get_flashed_messages

app = Flask(__name__)
app.secret_key = 'secret'

@app.route('/')
def index():
    flash('First message')
    flash('Second message', 'info')
    messages = get_flashed_messages(with_categories=True)
    return render_template_string('''<ul>{% for category, msg in messages %}<li>{{ category }}: {{ msg }}</li>{% endfor %}</ul>''', messages=messages)

A<ul><li>message: First message</li><li>info: Second message</li></ul>

B<ul><li>First message</li><li>Second message</li></ul>

C<ul><li>error: First message</li><li>info: Second message</li></ul>

D<ul><li>default: First message</li><li>info: Second message</li></ul>

Attempts:

2 left

🔧 Debug

advanced

2:00remaining

Why does the flash message not appear after redirect?

A developer flashes a message and redirects, but the message never shows. What is the most likely cause?

Flask

from flask import Flask, flash, redirect, url_for

app = Flask(__name__)

@app.route('/login')
def login():
    flash('Logged in successfully')
    return redirect(url_for('dashboard'))

@app.route('/dashboard')
def dashboard():
    return 'Dashboard page'

AThe flash message is not displayed because redirect clears it.

BThe flash message requires a template to be rendered, not a string.

CThe app.secret_key is missing, so session data (flash) is not saved.

DThe flash function must be called after redirect, not before.

Attempts:

2 left

🧠 Conceptual

expert

3:00remaining

How does Flask flash message storage and retrieval work internally?

Which statement best describes how Flask stores and retrieves flash messages for user feedback?

AFlash messages are stored in the user's session cookie and removed after being retrieved once.

BFlash messages are stored in a global server variable and shared across all users until cleared.

CFlash messages are saved in a database and fetched on each page load until expired.

DFlash messages are embedded in the URL query parameters and parsed on the next request.

Attempts:

2 left