django中如何有一个按具有关联的字段过滤的变更列表？

Question

Suppose I have two models:

class Blog(models.Model):
    pass

class Article(models.Model):
    blog = models.ForeignKey(Blog, related_name="articles")

I want to filter only blogs that have an article. The filter would be something like this:

Blog.objects.annotate(article_count=models.Count('articles')).filter(article_count__gt=0)

How can I have the change list at the admin filter like this? I tried a few approaches, like custom filterspecs, but had no success. The best solution was to use a proxy model and register a separated admin list, like this solution:

Multiple ModelAdmins/views for same model in Django admin

But that doesn't work very well with the permission system. Any ideas?

Answer 1

There's currently no way, aside from some very painful hacks, to accomplish that. Django 1.4 will ship with the ability to create custom filterspecs (see: https://code.djangoproject.com/ticket/5833 ), which will allow you to do stuff like this.

Since this seems to be kind of an edge case (really, how many blogs will ever have zero posts for a significant period of time?) My suggestion would be to just hold out for now, and maybe look into upgrading once 1.4 is released.

If you insist on going down the rabbit hole, you can start here: Custom Filter in Django Admin on Django 1.3 or below