Django admin - Mixing multiple model inlines in single admin interface

Question

I have a Django model layout that looks something like this:

class Author(models.Model):
    name = models.CharField(max_length=50, unique=True)

class Publication(models.Model):
    author = models.ForeignKey(Author)        

    #Some shared fields

    class Meta:
        abstract = True

class Book(Publication):
    #Book specific fields

class Poem(Publication):
    #Poem specific fields

Generally speaking, I'd like to show information listed by author and sorted by some information, like pub_date, so that the end user would see something like:

Author A:

• Poem 1
• Poem 2
• Book 1
• Poem 3
• Book 2

Author B:

• Book 1
• Book 2
• Poem 1
• Poem 2
• Book 3

And so on. I can figure out how to display these on the front-end (I can either use django-polymorphic or simply combine the author.book_set.all() and author.poem_set.all() into a single list and sort). But I CANNOT figure out how to implement this in the Admin site. I would like the structure to be exactly the same as above -- so that when I click on Author A I'd get:

• inline for Poem 1
• inline for Poem 2
• inline for Book 1
• inline for Poem 3
• inline for Book 2

If I simply attach Poem and Book as TabularInlines, they would be separated out into separate fieldsets, like so:

• inline for Poem 1
• inline for Poem 2

• inline for Poem 3

• inline for Book 1

• inline for Book 2

But I think it's important for functionality that they are mixed together in a single fieldset (with the fields specific to the other child class either grayed out or not present for each inline). Does anyone have any idea how to implement this?

Answer 1

Well, it didn't seem like there was a simple way to do this, so I delved into django.contrib a bit and built an app for handling this: Django Merged Inlines. If it would be useful to anyone, it's available here:

https://github.com/MattBroach/Django-Merged-Inlines