Add get_ascendings

src/documents/managers.py

 from django.db import models
+from itertools import groupby
 
 
 class DocumentManager(models.Manager):
@@ -8,6 +9,15 @@ class DocumentManager(models.Manager):
         """Get all parent documents for a specific document ID."""
         return self.filter(dp_parent__id=id).order_by('dp_parent__ordering')
 
+    def get_ascendings(self, *ids):
+        """Get all parent documents for some document IDs."""
+        from documents.models import DocumentParents
+        dps = DocumentParents.objects.filter(id__in=ids).order_by('id', 'ordering').only('id', 'parent').select_related('parent')
+        return {
+            pk: [dp.parent for dp in items]
+            for pk, items in groupby(dps, lambda d: d.id)
+        }
+
     def get_descending(self, id):
         """Get all child documents for a specific document ID."""
         return self.filter(dc_child__id=id).order_by('dc_child__ordering')