How can I use validators with Django serializers?

How can I use validators with Django serializers?

You can use validators in Django serializers to enforce rules on the data being serialized. For example, you can use built-in validators like MaxValueValidator or create custom validators.

Can you show me an example of a custom validator?

Sure! Here's a simple custom validator that checks if a value is even:

from rest_framework import serializers

class EvenValidator:
    def __call__(self, value):
        if value % 2 != 0:
            raise serializers.ValidationError('Value must be even.')

How do I apply this validator to a serializer field?

You can apply the custom validator to a serializer field like this:

class MySerializer(serializers.Serializer):
    my_field = serializers.IntegerField(validators=[EvenValidator()])

What happens if the validation fails?

If the validation fails, a ValidationError will be raised, and the error message you defined will be returned in the response.