Error messages from field.validators never used if the ValidationError has a code matching an error message on the Field

[Jonathan Buchanan]

Given the following field, I would have expected that validate_email's error message would haven been displayed:

>>> from django.conf import settings
>>> settings.configure()
>>> from django import forms
>>> from django.core import validators
>>> f = forms.CharField(validators=[validators.validate_email])
>>> f.clean('@@@@@@')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/insin/Virtualenvs/django-trunk/src/django/django/forms/fields.py", line 155, in clean
    self.run_validators(value)
  File "/home/insin/Virtualenvs/django-trunk/src/django/django/forms/fields.py", line 144, in run_validators
    raise ValidationError(errors)
django.core.exceptions.ValidationError: [u'Enter a valid value.']
>>> import django
>>> django.get_version()
'1.4a1'

The root issue is that many of the django.core.validators use the "invalid" error code, which is always going to be defined on the field as it's a default. I have a branch on GitHub which has one approach to updating this behaviour - using the validators' own error messages unless the message code has been customised on the field instance. The tests demonstrate a use case extending RegexValidator, which was raised as an issue in my JavaScript port of django.forms:

​https://github.com/insin/django/compare/validators-error-messages

Another approach would be to change the codes used by the OOTB validators away from 'invalid', as is already the case with BaseValidator and classes which extend it.

[Claude Paroz]

This is a duplicate of #17051