OpenConceptLab/ocl_issues#979 | cannot delete default expansion | exp…

…ansions count in version summary

core/collections/models.py

@@ -334,6 +334,10 @@ def seed_references(self):
     def is_validation_necessary():
         return False
 
+    @property
+    def expansions_count(self):
+        return self.expansions.count()
+
     def delete_references(self, expressions):
         if self.expansion_uri:
             self.expansion.delete_expressions(expressions)
@@ -591,6 +595,10 @@ def get_resource_url_kwarg():
     def get_url_kwarg():
         return 'expansion'
 
+    @property
+    def is_default(self):
+        return self.uri == self.collection_version.expansion_uri
+
     @property
     def expansion(self):
         return self.mnemonic
@@ -666,6 +674,9 @@ def seed_children(self, index=True):
         return self.add_references(self.collection_version.references, index)
 
     def calculate_uri(self):
+        version = self.collection_version
+        if version.is_head:
+            return self.collection_version.uri + 'HEAD/expansions/{}/'.format(self.mnemonic)
         return self.collection_version.uri + 'expansions/{}/'.format(self.mnemonic)
 
     def clean(self):

core/collections/serializers.py

@@ -180,10 +180,11 @@ class Meta:
 
 class CollectionSummarySerializer(ModelSerializer):
     versions = IntegerField(source='num_versions')
+    expansions = IntegerField(source='expansions_count')
 
     class Meta:
         model = Collection
-        fields = ('active_mappings', 'active_concepts', 'versions', 'active_references')
+        fields = ('active_mappings', 'active_concepts', 'versions', 'active_references', 'expansions')
 
 
 class CollectionSummaryDetailSerializer(CollectionSummarySerializer):
@@ -198,9 +199,11 @@ class Meta:
 
 
 class CollectionVersionSummarySerializer(ModelSerializer):
+    expansions = IntegerField(source='expansions_count')
+
     class Meta:
         model = Collection
-        fields = ('active_mappings', 'active_concepts', 'active_references')
+        fields = ('active_mappings', 'active_concepts', 'active_references', 'expansions')
 
 
 class CollectionVersionSummaryDetailSerializer(CollectionVersionSummarySerializer):

core/collections/views.py

@@ -591,6 +591,8 @@ class CollectionVersionExpansionView(CollectionVersionExpansionBaseView, Retriev
 
     def destroy(self, request, *args, **kwargs):  # pylint: disable=unused-argument
         obj = self.get_object()
+        if obj.is_default:
+            return Response(dict(erors=['Cannot delete default expansion']), status=status.HTTP_400_BAD_REQUEST)
         obj.delete()
         return Response(status=status.HTTP_204_NO_CONTENT)