added FilterBackends for local objects

djangoldp/filters.py

+from rest_framework.filters import BaseFilterBackend
+from djangoldp.models import Model
+
+
+class LocalObjectFilterBackend(BaseFilterBackend):
+    """
+    Filter which removes external objects (federated backlinks) from the queryset
+    For querysets which should only include local objects
+    """
+    def filter_queryset(self, request, queryset, view):
+        internal_ids = [x.pk for x in queryset if not Model.is_external(x)]
+        return queryset.filter(pk__in=internal_ids)
+
+
+class LocalObjectOnContainerPathBackend(LocalObjectFilterBackend):
+    """
+    Override of LocalObjectFilterBackend which removes external objects when the view requested
+    is the model container path
+    """
+    def filter_queryset(self, request, queryset, view):
+        if issubclass(view.model, Model) and request.path_info == view.model.get_container_path():
+            return super(LocalObjectOnContainerPathBackend, self).filter_queryset(request, queryset, view)
+        return queryset