Nested categories/InlinePanel(s) in wagtail

Question

I struggle to implement something like \"nested categories\":

PageA:
  - Cat1
    - SubCat1
    - SubCat2
    - ...
  - Cat2
    - SubCat1
  - ...

Answer 1

Here's one way to do it, with much room for interface improvements ;) In order to sort the categories at the page level, I'd suggest the use of django-sortedm2m.

from wagtail.wagtailcore.models import Orderable, Page
from wagtail.wagtailsnippets.models import register_snippet
from django.db import models


@register_snippet
class Category(models.Model):
    name = models.CharField(
        max_length=80, unique=True, verbose_name=_('Category Name'))
    slug = models.SlugField(unique=True, max_length=80)
    parent = models.ForeignKey(
        'self', blank=True, null=True, related_name="children",
        help_text=_(
            'Categories, unlike tags, can have a hierarchy. You might have a '
            'Jazz category, and under that have children categories for Bebop'
            ' and Big Band. Totally optional.')
    )
    description = models.CharField(max_length=500, blank=True)

    class Meta:
        ordering = ['name']
        verbose_name = _("Category")
        verbose_name_plural = _("Categories")

    panels = [
        FieldPanel('name'),
        FieldPanel('parent'),
        FieldPanel('description'),
    ]

    def __str__(self):
        return self.name

    def clean(self):
        if self.parent:
            parent = self.parent
            if self.parent == self:
                raise ValidationError('Parent category cannot be self.')
            if parent.parent and parent.parent == self:
                raise ValidationError('Cannot have circular Parents.')

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.name)
        return super(Category, self).save(*args, **kwargs)


class CategoryPage(models.Model):
    category = ParentalKey('Category', related_name="+", verbose_name=_('Category'))
    page = ParentalKey('MyPage', related_name='+')
    panels = [
        FieldPanel('category'),
    ]


class MyPage(Page):
    categories = models.ManyToManyField(Category, through=CategoryPage, blank=True)
    content_panels = Page.content_panels + [
        FieldPanel('categories'),
    ]