[FIXED] object-level validation in django serializers does not recognize function

Issue

class serializer_blahblah(serializers.ModelSerializer):
    """Serializer for ProfileUsefulRecommendations."""

    profile_id = serializers.UUIDField()
    recommendation_id = serializers.UUIDField()

    class Meta:
        """Meta class."""

        fields = (
            "id",
            "profile_id",
    ...

everything works perfectly with this serializer, however I decided to add object-level validation
Here is what happens:

    def validate(self, data):
        recommendation_id = str(data["recommendation_id"])
        print("recommendation: ", recommendation_id)
        validate_recommendation_id(recommendation_id=recommendation_id)
        print(validate_recommendation_id(recommendation_id=recommendation_id))
        return data

Print out:

recommendation:  3a232d0d-0705-4775-8bae-0e2f3d69c96c

It does not even recognize the function....

However, if I use exactly same function in individual field serializer, it goes well. But shortly speaking I need it as a object-level

ADDED the code of function:

def validate_recommendation_id(recommendation_id):
    try:
        Recommendation.objects.get(id=recommendation_id)
    except Recommendation.DoesNotExist as exception:
        raise serializers.ValidationError(
            {f"{recommendation_id}": "does not exist"}
        ) from exception
    return recommendation_id

Solution

Actually guys, I have come up with solution as such. Instead of validation function, I defined

Class CheckIfObjectHasId(queryset, lookup_object)

which later I called in serializers:

class serializer_blahblah(serializers.ModelSerializer):
    """Serializer for ProfileUsefulRecommendations."""

    profile_id = serializers.UUIDField(
        validators=[
             CheckIfObjectHasId(queryset=Profile.object.all(), lookup_object="id"
        ]
    )

Answered By - Aleksandre Bregadze