djangoldp/serializers_new.py

+from django.conf import settings
+from rest_framework.relations import HyperlinkedRelatedField, RelatedField
+from rest_framework.serializers import Serializer
+from djangoldp.models import Model
+from djangoldp.serializers import _serialize_rdf_fields
+
+
+class NewJsonLDRelatedField(RelatedField):
+    '''
+    Requirements for use:
+     * model has a urlid field (URL string)
+    '''
+    def to_representation(self, instance):
+        data = {
+            '@id': instance.urlid
+        }
+
+        rdf_type = Model.get_meta(instance, 'rdf_type', None)
+        if rdf_type is not None:
+            data.update({'@type': rdf_type})
+
+        return data
+
+    def to_internal_value(self, data):
+        # TODO: ...
+        # you have JSON-LD data, you want model instance
+        # main issue is not knowing the type
+        # the connected instance MUST exist
+        # the connected instance MAY be foreign
+        if '@type' in data:
+            model_class = Model.get_subclass_with_rdf_type(data['@type'])
+            return model_class.objects.get(urlid=data['@id'])
+
+
+class NewLDPSerializer(Serializer):
+    '''
+    Requirements for use:
+     * model has a urlid field, used as a unique identifier on the instance
+    '''
+
+    def external_instance_to_representation(self, instance):
+        '''called by to_representation when serializing external instances'''
+        data = {'@id': instance.urlid}
+        return _serialize_rdf_fields(instance, data)
+
+    def to_representation(self, instance):
+        # external Models should only be returned with rdf values
+        if Model.is_external(instance):
+            return self.external_instance_to_representation(instance)
+
+        data = super().to_representation(instance)
+
+        '''
+        slug_field = Model.slug_field(obj)
+        for field in data:
+            if isinstance(data[field], dict) and '@id' in data[field]:
+                data[field]['@id'] = data[field]['@id'].format(Model.container_id(obj), str(getattr(obj, slug_field)))
+        '''
+
+        # prioritise urlid field over generated @id
+        if 'urlid' in data and data['urlid'] is not None:
+            data['@id'] = data.pop('urlid')['@id']
+        # TODO: raise error or try to treat it?
+        '''if not '@id' in data:
+            try:
+                data['@id'] = '{}{}'.format(settings.SITE_URL, Model.resource(obj))
+            except AttributeError, NoReverseMatch:
+                pass'''
+
+        data = _serialize_rdf_fields(instance, data, include_context=True)
+
+        # permissions serialization: depends on request!
+        '''
+        if hasattr(obj, 'get_model_class'):
+            model_class = obj.get_model_class()
+        else:
+            model_class = type(obj)
+        data['permissions'] = _serialize_object_permissions(
+            Model.get_permissions(model_class, self.context['request'], self.context['view'], obj))
+        '''
+        
+        return data
+
+    def to_internal_value(self, data):
+        if '@id' in data and not 'urlid' in data:
+            data['urlid'] = data.pop('@id')
+        
+        return super().to_internal_value(data)