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

Answer 1

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.