Django中的元编程get_foo_display，foo_set等，它是如何工作的？

Question

I have a user model with a profile UserProfile. Somehow my user can have several type of books: TA, TB, TC, TD. Those choices are defined in a choices tuple in my model (standard way).

From my template I would like to be able to call

{{ user.get_profile.has_book_type_TA }} 

and returns True/False.

TA is the dynamic part, it could be rewritten as:

has_book_type_[type_name]

How can I write this kind of method in my model ?

def has_book_type_(self, type_name):
    ...

But how to make it callable as get_profile.has_book_type_TA

Answer 1

In the __init__ method for your model, walk through the different types of books and create properties:

for book_type in BOOK_TYPES:
  setattr(self, 'has_book_type_%s' % book_type, self.has_book_type_(book_type))

Then in your templates, checking user.get_profile.has_book_type_TA should work.