Question

I have created the following TagBase and each category can have subcategory…
Will this work? How can I override its add function in the TaggableManager?

 class Category(TagBase):
        parent = models.ForeignKey('self', blank=True, null=True,
                                   related_name='child')
        description = models.TextField(blank=True, help_text="Optional")

        class Meta:
            verbose_name = _('Category')
            verbose_name_plural = _('Categories')

Answer 1

django-taggit/docs/custom_tagging.txt describes how. You must define an intermediary model with a foreign key tag to your TagBase subclass.

from django.db import models
from taggit.managers import TaggableManager
from taggit.models import ItemBase

# Required to create database table connecting your tags to your model.
class CategorizedEntity(ItemBase):
    content_object = models.ForeignKey('Entity')
    # A ForeignKey that django-taggit looks at to determine the type of Tag
    # e.g. ItemBase.tag_model()
    tag = models.ForeignKey(Category, related_name="%(app_label)s_%(class)s_items")

    # Appears one must copy this class method that appears in both TaggedItemBase and GenericTaggedItemBase
    @classmethod
    def tags_for(cls, model, instance=None):
        if instance is not None:
            return cls.tag_model().objects.filter(**{
                '%s__content_object' % cls.tag_relname(): instance
            })
        return cls.tag_model().objects.filter(**{
            '%s__content_object__isnull' % cls.tag_relname(): False
        }).distinct()

class Entity(models.Model):
    # ... fields here

    tags = TaggableManager(through=CategorizedEntity)