Serializer base class to implement common name validation for the child serializers.

common_name_filed_case_validation.py

# ===== Models =====

class Country(models.Model):
    name = models.CharField(max_length=150, unique=True)

class Molecule(models.Model):
    name = models.CharField(max_length=150, unique=True)

class TherapeuticCategory(models.Model):
    name = models.CharField(max_length=150, unique=True)


# ===== Serializers =====

class CommonMasterDataSerializer(serializers.ModelSerializer):
    """Base class to implement common functionalities for the serializers"""

    def validate_name(self, name):
        queryset = self.Meta.model.objects.filter(name__iexact=name)

        # In update operation exclude this model instance from the lookup
        if self.instance:
            queryset = queryset.exclude(id=self.instance.pk)

        if queryset.exists():
            raise serializers.ValidationError(
                f"This {self.Meta.model._meta.verbose_name.lower()} already exists."
            )

        return name

class CountrySerializer(CommonMasterDataSerializer):
    class Meta:
        model = Country
        fields = '__all__'


class MoleculeSerializer(CommonMasterDataSerializer):
    class Meta:
        model = Molecule
        fields = '__all__'

class TherapeuticCategorySerializer(CommonMasterDataSerializer):
    class Meta:
        model = TherapeuticCategory
        fields = '__all__'


# ===== Viewsets ========

class CountryViewSet(viewsets.ModelViewSet):
    queryset = Country.objects.all().order_by('name')
    serializer_class = CountrySerializer


class MoleculeViewSet(viewsets.ModelViewSet):
    queryset = Molecule.objects.all().order_by('name')
    serializer_class = MoleculeSerializer


class TherapeuticCategoryViewSet(viewsets.ModelViewSet):
    queryset = TherapeuticCategory.objects.all().order_by('name')
    serializer_class = TherapeuticCategory


# ===== URLs ========

router.register('countries', CountryViewSet)
router.register('molecule', MoleculeViewSet)
router.register('therapeutic-category', TherapeuticCategoryViewSet)