django-taggit==1.2.0
Django==3.0.8
class TagMixin(models.Model):
tags = TaggableManager(verbose_name="Tags") # django-taggit
class Meta:
abstract = True
class Post(TagMixin,
models.Model):
category = models.ForeignKey(Category,
on_delete=models.PROTECT,
verbose_name="Category")
def is_featured(self):
return SPECIAL_TAGS.FEATURED.value in self.tags.names()
def is_news(self):
return self.category.slug == SPECIAL_CATEGORIES.NEWS.value
def _validate_featured(self):
if not self.is_news() and self.is_featured():
raise ValidationError("Featured can be in News only.")
Problem
In the admin site there is Tags field visible. But really it is not a field. It is a manager.
Therefore my validator doesn't work properly: it doesn't validate tags the field in the admin site.
What is_featured() does is extracting tag names from the database.
How can I validate what tags are input by a user? The validation requires access to more than a just tags (as you can see, it implies interdependency between tags and categories).
