fix: make serialize_tag_data a classmethod

so we can serialize tags for blocks that aren't officially TaggedXBlocks

cms/djangoapps/contentstore/views/tests/test_block.py

@@ -1138,11 +1138,11 @@ def test_duplicate_tags(self):
         # Refresh.
         source_chapter = self.store.get_item(source_chapter.location)
         expected_chapter_tags = 'A:one,two;B:four,three'
-        assert source_chapter.serialize_tag_data() == expected_chapter_tags
+        assert source_chapter.serialize_tag_data(source_chapter.location) == expected_chapter_tags
 
         source_block = self.store.get_item(source_block.location)
         expected_block_tags = 'A:two'
-        assert source_block.serialize_tag_data() == expected_block_tags
+        assert source_block.serialize_tag_data(source_block.location) == expected_block_tags
 
         # Duplicate the chapter (and its children)
         dupe_location = duplicate_block(
@@ -1155,8 +1155,8 @@ def test_duplicate_tags(self):
         dupe_block = dupe_chapter.get_children()[0]
 
         # Check that the duplicated blocks also duplicated tags
-        assert dupe_chapter.serialize_tag_data() == expected_chapter_tags
-        assert dupe_block.serialize_tag_data() == expected_block_tags
+        assert dupe_chapter.serialize_tag_data(dupe_chapter.location) == expected_chapter_tags
+        assert dupe_block.serialize_tag_data(dupe_block.location) == expected_block_tags
 
 
 @ddt.ddt

cms/lib/xblock/tagging/tagged_block_mixin.py

@@ -31,9 +31,10 @@ def tags_v1(self, tags: str) -> None:
         """
         self._tags_v1 = tags
 
-    def serialize_tag_data(self):
+    @classmethod
+    def serialize_tag_data(cls, usage_id):
         """
-        Serialize block's tag data to include in the xml, escaping special characters
+        Serialize a block's tag data to include in the xml, escaping special characters
 
         Example tags:
             LightCast Skills Taxonomy: ["Typing", "Microsoft Office"]
@@ -45,7 +46,7 @@ def serialize_tag_data(self):
         # This import is done here since we import and use TaggedBlockMixin in the cms settings, but the
         # content_tagging app wouldn't have loaded yet, so importing it outside causes an error
         from openedx.core.djangoapps.content_tagging.api import get_object_tags
-        content_tags = get_object_tags(self.scope_ids.usage_id)
+        content_tags = get_object_tags(usage_id)
 
         serialized_tags = []
         taxonomies_and_tags = {}
@@ -69,7 +70,7 @@ def add_tags_to_node(self, node):
         """
         Serialize and add tag data (if any) to node
         """
-        tag_data = self.serialize_tag_data()
+        tag_data = self.serialize_tag_data(self.scope_ids.usage_id)
         if tag_data:
             node.set('tags-v1', tag_data)