Override default django username validators for AbstractUser model

Question

I am using the AbstractUser model to create a custom auth model.

The problem is that i was unable to override the default form field validators for the username fie

Answer 1

You can explicitly define a field on the form. That way, you have full control over the field, including its validators:

class RegularUserForm(forms.ModelForm):
    username = forms.CharField(max_length=30)

    class Meta:
        model = User

Answer 2

Thankfully i found the solution, i was overriding the validators in the forms but not the ones in the models (also did the opposite) so i had to do this:

from utils import validate_username
class RegularUserForm(forms.ModelForm):
    username = forms.CharField(max_length=50, validators=[validate_username])

and

class RegularUser(AbstractUser):
    def __init__(self, *args, **kwargs):
        super(RegularUser, self).__init__(*args, **kwargs)
        self._meta.get_field('username').validators = [validate_username]

Note for readers: make sure you override both model and form level validators!