flask4

Server Side Programming exercises (Python, Flask), Part IV.

• Flask QuickStart
• Jinja Templates

Exercise #1: Remembering user details

Make a form that asks for the user's name and email address, and then remembers the values using cookies.

• Check (in the python code) if both name and email are provided. If not, display an error message.
• Remember the user's details for 60 days.
• The user should also be able to "be forgotten" by clicking on a link.
• Upon successful operations (remembering or forgetting), show a success message.
• Use message flashing with success and error categories for displaying these messages. The messages should be displayed inside the <main> element, above the content part. The style definitions are already created for the success and error classes.

The skeleton of the app is provided, which already includes the form that asks for the name and email and methods for the requests (to be completed).

Visiting http://127.0.0.1:5000/ before the user's details are remembered: Visiting http://127.0.0.1:5000/ after the user's details are remembered:

Exercise #2: Shopping cart

The task is to manage the contents of a shopping cart using sessions.

• List the contents of the shopping cart.
• Add a new product to the shopping cart.
  • Adding is done via a form that uses a POST method.
  • If the product is already in the shopping cart, increase its quantity.
  • Return a 400 (Bad Request) HTTP error if product ID or quantity are missing. Otherwise show a success message.
• Remove a given product that is in the shopping cart.
  • Removing products is done via a GET request (/remove?product_id=xxx).
  • If the product to be removed is not in the shopping cart, then return a 400 HTTP error. Otherwise show a success message.
• Create a custom error page for error 400.

The skeleton of the app is provided, which already includes the HTML parts and a Python class for representing the shopping cart. Complete the missing parts of app.py and make the necessary changes under templates/.

• Hint: save the contents of the shopping cart in the session, that is, the dict that is returned by contents(). When loading the cart's contents from the session, initialize the ShoppingCart class with what is stored in the session.

Exercise #2b: Shopping cart

Extend the previous exercise such that the user can modify the quantities in the cart.