Django REST framework: Serializer to use max_length from model

Question

I have a model

class Person(models.Model):
    name = models.CharField(max_length=254)

and related serializer

class PersonSerializer(serializers.ModelSerializer):
    name = serializers.CharField(required=True, max_length=254)

    class Meta:
        model = Person
        fields = ('name',)

Is there a way to make CharField automatically detect max_length from the model and use that in validation?

Using Person._meta.get_field('name').max_length could be an option but feels a bit cumbersome to be used in every field. Maybe overriding CharField with custom implementation? Or is there other options?

Use a ModelSerializer, and let Django convert the fields to their serializer field counterparts. — willeM_ Van Onsem
– willeM_ Van Onsem, Commented May 9, 2022 at 9:51
This seems to work fine when fields are just declared in Meta section. But if there is a need to add custom arguments to fields, then e.g. max_length is not transferred from model. For example name = serializers.CharField(required=True) doesn't use max_length validation — TCFDS
– TCFDS, Commented May 9, 2022 at 10:19
You can use extra_kwargs to inject extra parameters: django-rest-framework.org/api-guide/serializers/… — willeM_ Van Onsem
– willeM_ Van Onsem, Commented May 9, 2022 at 10:36

willeM_ Van Onsem · Accepted Answer · 2022-05-09 10:38:27Z

1

If you want to translate a model in a straightforward way to a serializer, you can use a ModelSerializer. You can inject extra parameters to the constructors of the serializer fields with the extra_kwargs field ^[drf-doc], so:

class PersonSerializer(serializers.ModelSerializer):

    class Meta:
        model = Person
        fields = ('name',)
        extra_kwargs = {
            'name': {'required': True}
        }

answered May 9, 2022 at 10:38

willeM_ Van Onsem

482k33 gold badges483 silver badges624 bronze badges

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

Collectives™ on Stack Overflow

Django REST framework: Serializer to use max_length from model

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related