Django: Display a custom error message for admin validation error

I'm using Django 1.2.4. I have a model that has a field that needs to be validated. When validation fails, I'd like to display a custom error message to the user. Model editing is done in the admin interface.

This is what I'm doing currently:

def clean_fields(self, exclude=None):
    # do validation
    if problem:
        raise ValidationError({'field_name': "er开发者_开发问答ror message"})

Unfortunately, all this does is print out a separate validation message on the admin page for each character in the value of field_name.

What is the proper way to signal the error message I want?

Without looking, it sounds like the admin is looking for an iterable as the value for field_name. Try:

raise ValidationError({'field_name': ["error message",]})

I think the admin expects any number of validation messages to be associated with each field on a form.