Django model subclassing: Get the subclass by querying the superclass

Question

The following code is given:

class BaseMedium(models.Model):
    title = models.CharField(max_length=40)
    slug = models.SlugField()

class A(BaseMedium):
         


        

Answer 1

This worked for me (using self.subclass_name_in_lower_case): In this example subclasses are TextTreeItem, CategoryTreeItem and KeywordTreeItem.

class TreeItem(MPTTModel):
    parent = TreeForeignKey('self', on_delete=models.CASCADE, verbose_name=_('Parent'),
                            null=True, blank=True, related_name='%(class)s_related')

    objects = CustomTreeManager()

    @property
    def daughter(self):
        try:
            return self.texttreeitem
        except TreeItem.texttreeitem.RelatedObjectDoesNotExist:
            pass

        try:
            return self.categorytreeitem
        except TreeItem.categorytreeitem.RelatedObjectDoesNotExist:
            pass

        try:
            return self.keywordtreeitem
        except TreeItem.keywordtreeitem.RelatedObjectDoesNotExist:
            return self