Update content block mutation

server/book/schema/mutations.py

@@ -95,26 +95,45 @@ class AddContentBlock(relay.ClientIDMutation):
     class Input:
         content_block = graphene.Argument(ContentBlockInput)
         #  todo: handle both of these differently, one for a new chapter maybe
-        parent = graphene.ID()
-        after = graphene.ID()
+        parent = graphene.ID()  # ID of chapter node; new content block will be inserted at the start of it
+        after = graphene.ID()  # ID of content block node; new content block will be inserted after this content block node
 
     new_content_block = graphene.Field(ContentBlockNode)
+    errors = graphene.List(graphene.String)
+
+    @classmethod
+    def create_content_block(cls, content_block_data):
+        title = content_block_data.get('title')
+        contents = content_block_data.get('contents')
+        new_contents = handle_content_blocks(contents)
+        return ContentBlock(title=title, contents=new_contents)
 
     @classmethod
     def mutate_and_get_payload(cls, root, info, **args):
-        content_block_data = args.get('content_block')
-        title = content_block_data.get('title')
-        new_content_block = ContentBlock(title=title)
-        parent = Chapter.objects.get(
-            pk=18).specific  # atm just "1.1 Lehrbeginn" / todo: dynamic, refactor in above class
-        parent.add_child(instance=new_content_block)
-        revision = new_content_block.save_revision()
-        revision.publish()
-        contents = content_block_data.get('contents')
-        new_contents = handle_content_blocks(contents)
-        new_content_block.contents = json.dumps(new_contents)
-        new_content_block.save()
-        return cls(new_content_block=new_content_block)
+        try:
+            parent = args.get('parent', None)
+            after = args.get('after', None)
+            if after is not None:
+                new_content_block = cls.create_content_block(content_block_data=args.get('content_block'))
+                sibling = get_object(ContentBlock, after)
+                sibling.add_sibling(instance=new_content_block, pos='right')
+            elif parent is not None:
+                new_content_block = cls.create_content_block(content_block_data=args.get('content_block'))
+                parent = get_object(Chapter, parent)
+                parent.add_child(instance=new_content_block)
+            else:
+                raise Exception('Define either a parent or a sibling id')
+            revision = new_content_block.save_revision()
+            revision.publish()
+            new_content_block.save()
+            return cls(new_content_block=new_content_block)
+
+        except ValidationError as e:
+            errors = get_errors(e)
+        except Exception as e:
+            errors = ['Error: {}'.format(e)]
+
+        return cls(new_content_block=None, errors=errors)
 
 
 class BookMutations(object):