[Python APIView] display decorators on models

[mikekistler]

From @annatisch

it seems that APIview currently only displays decorators for methods, is it possible to add support for displaying decorators on models as well to prevent this being missed in future?

[tjprescott]

@annatisch @johanste so the issue here is that Python APIView renders essentially the "compiled" Python, meaning that when we are inspecting the live Python objects, any class decorators have already been applied, and we are seeing the resulting impact of them.

Consider this:

def get_id(self):
    return self.__id

def add_id(cls):
    cls_init = cls.__init__

    def __init__(self, id, *args, **kwargs):
        self.__id = id
        self.get_id = get_id
        cls_init(self, *args, **kwargs)

    cls.__init__ = __init__
    return cls

@add_id
class ClassWithDecorators:
    pass

What do you want to see in APIView?

Today you would see the result of @add_id applied:

# Option 1: render the final result of the applied decorator
class ClassWithDecorators:
  def __init__(self, id, *args, **kwargs)

I can parse into the source to extract and render the decorator statement, but it will still have the "applied" change to __init__:

# Option 2: render the "applied" body but still annotate the decorators
@add_id
class ClassWithDecorators:
  def __init__(self, id, *args, **kwargs)

To render it as it is in source I would either need to somehow "subtract" the applied __init__ or, given how hacky that would likely be, just switch to parsing the entire class definitions from source. Parsing from source is, for presumably good reasons, only done by exception in Python APIView today.

# Option 3: render how it appears in source
@add_id
class ClassWithDecorators:
    pass