Let Media classes to inherit

[Aleksander Zdyb]

Media classes in ModelAdmin or Form cannot inherit from other classes:

class BaseMedia:
    css = {"all": ["base.css", ] }

class ExampleAdmin(ModelAdmin):
    class Media(BaseMedia):
        js = ["example.js, ]    

In the example above, only js media will be available. This is because of the following code in django/forms/widgets.py:

class Media(StrAndUnicode):
    def __init__(self, media=None, **kwargs):
        if media:
            media_attrs = media.__dict__
        else:
            media_attrs = kwargs

__dict__ doesn't include inherited properties.

My proposal is to use getmembers from inspect module:

media_attrs = dict(getmembers(media))

I've attached a 2-lines patch. All unit tests passed against revision 17377.

[Łukasz Rekucki]

The patch needs tests.

[Roman Gladkov]

tests for this patch

[Aymeric Augustin]

This is a duplicate of #9357.