python - Making a Django form class with a dynamic number of fields

Question

I'm working on something like an online store. I'm making a form in which the customer buys an item, and she can choose how many of these item she would like to buy. But, on every item that she buys she needs to choose what its color would be. So there's a non-constant number of fields: If the customer buys 3 items, she should get 3 <select> boxes for choosing a color, if she buys 7 items, she should get 7 such <select> boxes.

I'll make the HTML form fields appear and disappear using JavaScript. But how do I deal with this on my Django form class? I see that form fields are class attributes, so I don't know how to deal with the fact that some form instance should have 3 color fields and some 7.

Any clue?

Answer 1

Jacob Kaplan-Moss has an extensive writeup on dynamic form fields: http://jacobian.org/writing/dynamic-form-generation/

Essentially, you add more items to the form's self.fields dictionary during instantiation.