Is there an elegant way to have a list_filter for a M2M field in the Django admin?

If I have a Pizza model and a Topping model, with m2m between them, is there some quick elegant way to ad开发者_JAVA技巧d to the admin list page for either of them a list filter for all pizzas which contain a certain topping / all toppings that are contained in a certain pizza?

The built-in list_filter doesn't support m2m fields so I'm looking for some workaround to allow this sort of filtering.

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You can make your own custom FilterSpec.
Custom Filter in Django Admin on Django 1.3 or below
http://djangosnippets.org/snippets/1963/
http://www.djangosnippets.org/snippets/1051/

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Django 1.5+ supports m2m fields:

class Post(models.Model):
    categories = models.ManyToManyField(Category,
                                        verbose_name=_("Categories"),
                                        blank=True,
                                        related_name="posts")

class PostAdmin(admin.ModelAdmin):
    list_filter = ['categories__title',]