CODEWITHSUNDEEP
djangodjango-forms
Eric Schoonover
Eric Schoonover

Reputation: 48402

Django ModelForm is_valid() error types

I have a EmailField(primary_key=True). I'm using a ModelForm to render a form to a user and on the post back I am calling form.is_valid().

I am seeing two types of errors on this field. One is a unique value constraint on the primary key (this email address already exists). The other is an invalid email address error.

I would like to respond differently to each error. Is there an easy way to identify that validation failure was due to an actual input format error vs a unique constraint?

Upvotes: 2

Views: 1479

Answers (2)

Eric Schoonover
Eric Schoonover

Reputation: 48402

I figured out how to achieve what I wanted. My goal was to avoid the unique constraint so that I could silently ignore the form submission and succeed (from the user perspective, since their submission was a noop) in the case of a duplicate email address being submitted.

First override the validate_unique method on my ModelForm definition.

from django.forms import ModelForm
from apps.announcer.models import Subscriber

class SubscribeForm(ModelForm):
    class Meta:
        model = Subscriber
        exclude = ('created',)

    def validate_unique(self):
        pass

Because the validate_unique method has been converted to a noop the view will have to perform whatever validation it needs. So instead of calling form.save() call entity = form.save(commit=False). Perform the needed validation on entity and if needed call entity.save().

Upvotes: 5

Mike DeSimone
Mike DeSimone

Reputation: 42805

Could you check for a pre-existing key first, then call is_valid()?

Upvotes: 1

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