CODEWITHSUNDEEP
djangodjango-modelsdjango-forms
KevTuck
KevTuck

Reputation: 113

Validate Django Admin Inline Formset

I need to validate that an inline formset has a unique value. The idea is to be able to add a competition with a question and multiple answers. We can flag the correct answer using a checkbox, however I need to ensure that no more than one checkbox is ever selected or saved. I have tried validating with a clean() on the model side and also by extending BaseInlineFormSet, but then I seem to struggle to iterate over the formset and get any values. 

class Competition(models.Model):

    title = models.CharField(max_length=255)
    slug = models.SlugField(unique=True, blank=False)
    content = models.TextField()
    terms = models.TextField()


class Question(models.Model):
    competition = models.OneToOneField(
        Competition,
        on_delete=models.CASCADE,
        primary_key=True,
    )
    question = models.CharField(max_length=255)


class Answer(models.Model):

    question = models.ForeignKey(Question)
    answer = models.CharField(max_length=255)
    is_correct = models.BooleanField(default=False)

Upvotes: 2

Views: 1820

Answers (1)

KevTuck
KevTuck

Reputation: 113

So after a nights sleep I appear to have managed to fix it

from django.forms.models import BaseInlineFormSet
from django.core.exceptions import ValidationError

class AnswerInlineFormSet(BaseInlineFormSet):

    def clean(self):

        super(AnswerInlineFormSet, self).clean()
        total_checked = 0

        for form in self.forms:
            if not form.is_valid():
                return
            if form.cleaned_data and not form.cleaned_data.get('DELETE'):
                if form.cleaned_data['is_correct']:
                    total_checked += 1

        if total_checked > 1:
            raise ValidationError("You cannot have more than one correct answer")

        if total_checked < 1:
            raise ValidationError("You must have at least one correct answer")

Upvotes: 2

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