Multiple nested choices in Django models-CodePudding

Forgive me if I'm not describing this correctly - I'm still learning and I've hit a wall with a problem I'm working on. I want to create a way (in the Admin backend for now) for users to show the books they like by fiction/non-fiction, age-range, genre(s) and sub-genre(s). So, a user who liked gothic horror books could select fiction>adult>horror>gothic. Or, a user who likes literally all YA books could select fiction>Young Adult and their selection would cascade down to every genre and sub-genre.

I think the Choices field option and the MultiSelectField functionality might be a start, but there doesn't seem to be a way to add 'layers' to the choices beyond the categories below, and it seems like an inelegant solution when there could be hundreds of choices. I also don't know how it could be presented in the Admin - ideally with checkboxes that can 'open up' to show the sub-categories beneath them.

    GENRE_CHOICES = (
    ('Fiction', (
        ('FCH', 'Childrens'),
        ('FMG', 'Middle Grade'),
        ('FYA', 'Young Adult'),
        ('FAD', 'Adult'),
    )),
    ('Non-Fiction', (
        ('NCH', 'Childrens'),
        ('FMG', 'Middle Grade'),
        ('FYA', 'Young Adult'),
        ('FAD', 'Adult'),
    )),
)
genres = MultiSelectField(max_length = 100, choices=GENRE_CHOICES, null=True)

I don't even know the name of what I'm looking for here, so if anyone can point me in the right direction that'd be great.

CodePudding user response：

If you want the user to filter the list of books based on their preferences, then see django-filter https://django-filter.readthedocs.io/en/stable/index.html
(unfortunately I don't have enough reputation to write this to the commertary)

CodePudding user response：

What you are looking for is 'tree structure'. You can define it in multiple ways, for example the way you implement tree in database:

class Tree(models.Model):
  parent = models.ForeignKey('self', ...)

But there is better approach, which is somehow similar to what you wanted to use in the first place, please refer to django-mptt TreeNodeMultipleChoiceField