Enhance the model methods added when Meta.order_with_respect_to is used

[César García Tapia]

With order_with_respect_to, we can do something like this:

class Book(models.Model):
    pass

class Chapter(models.Model):
    book = models.ForeignKey(Book, on_delete=models.CASCADE)

    class Meta:
        order_with_respect_to = 'book'

It would be very nice to add some obvious features to this feature, for example:

• book.get_chapter_order() returns the IDs of the chapters. Why not the chapter objects itself?

• Given a chapter, we can get the next and the previous chapters, but we can't easily get that chapter's order.

• It would be very nice to be able to add a chapter directly in a specific position, pretty much like python's insert. For example: book.insert_chapter(chapter, 3)

I know it's a very broad request, but, if you guys like the idea, I'd love to take a look if I can add the functions myself (one at a time, to get your approval on each of them).

[Tim Graham]

Ideally, a ticket should propose one feature rather than several. I'm not sure what complexity might be involved in these issues, but I guess we could evaluate a patch.