DRF Improved Relations

What does it do?

This package allows you to set relation from API request by primary key, object's dict, list of PKs, list of dicts of mixed list.

For example

{
	"name": "Quentin Tarantino",
	"person_type": {"id": 10, "name": "Director"},  // dict (field ID is only required)
	"city": 15,  // primary key
	"movies": [  // list
		15431,  // can be primary key
		{"id": 31123},  // can be dict
		{"id": 21100, "name": "Pulp Fiction"}
	]
}

How to use it?

RelatedField

RelatedField is class implemented of PrimaryKeyRelatedField.

It has:

• serializer Serializer class used for serializing objects (list, retrieve...)
• fail_on_not_found Raise NotFound exception if object not found
• extra_filter Extra fields added to .filter()

class PersonSerializer(ModelSerializer):
	person_type = RelatedField(serializer=TypeSerializer)
	city = RelatedField(serializer=CitySerializer, required=False, fail_on_null=False, fail_on_not_found=False, 						extra_filter={'country': Country.objects.filter(name='USA')})
	movies = RelatedField(serializer=MovieSerilizer, many=True)

	class Meta(object):
		model = Person
		fields = ('id', 'name', 'person_type', 'city', 'movies')

get_related_object

get_related_object(search, model, fail_on_null=True, create_on_null=False, fail_on_not_found=True, extra_filter=None)

This function searches model instance by search (which would be primary key, dict with "id" field or list).

Attributes:

• search Primary key, dict with "id" field or list of primary keys
• model Model to search in
• fail_on_null *Raise ValidationError if search is None or incorrect
• fail_on_not_found Raise ValidationError if an instance was now found (does not work with list)
• create_on_null Try to create a new object
• extra_filter Extra fields added to .filter()

get_relation_from_request

get_relation_from_request(request, key: str, data: dict, model, fail_on_empty=False, fail_on_null=True,
                              fail_on_not_found=True, create_on_null=False, types=None, extra_filter=None)

This function gets value from request, search instance by get_related_object() and put it to data.

Attributes:

• request HttpRequest
• key Key to get value from request data
• data Dict to put gotten instance in
• model Model to search in
• fail_on_empty Raise ValidationError if there is no key in request
• fail_on_null *Raise ValidationError if search is None or incorrect
• fail_on_not_found Raise ValidationError if an instance was now found (does not work with list)
• create_on_null Try to create a new object
• types List of allowed value types
• extra_filter Extra fields added to .filter()

How to use it:

def perform_create(self, serializer):
	data = dict()
	get_relation_from_request(self.request, 'person_type', data, PersonType)
	get_relation_from_request(self.request, 'city', data, City, fail_on_empty=False, 
							  extra_fields={'country': Country.objects.filter(name='USA')})
	get_relation_from_request(self.request, 'movies', data, Movie)
	serializer.save(**data)