errors in fields not displaying on Django admin form

Question

I have a Django admin form which has an known source of errors that prevent the form from being saved. I have checked all the fields in the model, and all the required fields have been filled out. Nevertheless, I continue to get the standard error message:

Please correct the error below.

at the top of the form, yet no fields are highlighted with an error message.

What can be another cause, and how do I debug this?

Answer 1

Here is how you can see what the hidden errors are. Above your form class (create one if it doesn't already exist), add these imports:

# get a way to log the errors:
import logging
log = logging.getLogger(__name__)
# convert the errors to text
from django.utils.encoding import force_text

Then add to your form class this def:

class MyAdminForm(forms.ModelForm):

    def is_valid(self):
        log.info(force_text(self.errors))
        return super(MyAdminForm, self).is_valid()

When you examine your log after submitting again, it will list all the hidden errors.

When I had this problem, I found the cause of the errors were some 'calculated' read-only fields that I had added to the form, e.g.:

get_num_items = forms.IntegerField()

The validation failed since these fields had no value as required. Changing the field definition to include required=False fixed the problem:

get_num_items = forms.IntegerField(required=False)