Django Models: How to retrieve custom error messages in view function?

Question

I have a model UserProfile:

class UserProfile(models.Model):

    class Meta:
        db_table = 't_user_profile'

    display_name = models.CharField(
        max_length=20,
        unique=True,
        error_messages={
            'unique': ("A user with that display name already exists."),
        },
        blank=True
    )

I have a view function:

@csrf_exempt
def change_display_name(request):

    data = json.loads(request.body.decode('utf-8'))
    display_name = data.get('displayName')

    try:
        user_profile = UserProfile.objects.get(id=2)

    except UserProfile.DoesNotExist:
        return JsonResponse({'error': 'User does not exist.'}, safe=False)

    user_profile.display_name = display_name
    user_profile.save()

    return JsonResponse({'status': 'SUCCESS'}, safe=False)

How do I try except the unique display_name and return in JSON the custom error message I setup in my model?

as display_name is your only input of user_profile model, you can catch integrity error send your response. — Shakil
– Shakil, Commented Feb 14, 2019 at 11:52
You should use a form for this. Or, since you're dealing with JSON, you should use Django REST Framework and its serializers to manage the whole thing. — Daniel Roseman
– Daniel Roseman, Commented Feb 14, 2019 at 11:57

Jrog · Accepted Answer · 2019-02-14 11:57:47Z

0

Do You want to handle UNIQUE intergrityError? See this question

answered Feb 14, 2019 at 11:57

Jrog

1,52711 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

malberts · Accepted Answer · 2019-02-14 11:57:55Z

0

You need to run validation before saving. Here is an example based on the documentation:

from django.core.exceptions import ValidationError

user_profile.display_name = display_name

try:
    user_profile.full_clean()
except ValidationError as e:
    # Do something based on the errors contained in e.message_dict.
    return JsonResponse({'error': 'Some error message.'}, safe=False)

user_profile.save()

If, for some reason, you don't want to do full validation, you can check just the uniqueness constraints with user_profile.validate_unique() instead of full_clean(). Read more here.

answered Feb 14, 2019 at 11:57

malberts

2,5361 gold badge14 silver badges18 bronze badges

Collectives™ on Stack Overflow

Django Models: How to retrieve custom error messages in view function?

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related