Django: Does model_instance.clean() run before basic validators?
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22-09-2019 - |
Question
Let's say that I have a model:
class Ticket(models.Model):
client = models.ForeignKey(Client)
color = models.CharField(max_length=255)
def clean(self):
self.color = self.client.favorite_color
When I run this on the latest Django (head of the SVN from 15 minutes ago), if I hit save without selecting a client
, I get a DoesNotExist
error from inside my clean method (for the self.client.favorite_color
part). Since the model requires the client
attribute, shouldn't this be handled before my custom validation in clean()
?
Here's the documentation I'm reading: http://docs.djangoproject.com/en/dev/ref/models/instances/#id1
Solution
I figured it out if anyone runs into this problem:
In full_clean() on the model, first clean_fields() is run, but no errors are raised for display, etc. Instead they are simply added to a dict() and then clean(), which is the custom validation method for your model is run to add any of your custom errors to the dict. Only after that are the errors raised again.
OTHER TIPS
clean()
is a callable of ModelForms, not models.
To do what you seem to want to do at the Model level, override the save()
method.
Edit after comment: Well, it appears it is time to read the docs all over again with 1.2 impending. :-) Thanks for pointing it out.