fix: serialize the Text (HTML) XBlock's include_theme setting [WIP]

openedx/core/lib/xblock_serializer/block_serializer.py

@@ -171,6 +171,8 @@ def _serialize_html_block(self, block) -> etree.Element:
             olx_node.attrib["editor"] = block.editor
         if block.use_latex_compiler:
             olx_node.attrib["use_latex_compiler"] = "true"
+        if "include_theme" in block.fields and block.include_theme:
+            olx_node.attrib["include_theme"] = "true"
         for field_name in block.fields:
             if (
                 field_name.startswith(("upstream", "downstream")) or field_name == "top_level_downstream_parent_key"

openedx/core/lib/xblock_serializer/test_api.py

@@ -189,6 +189,60 @@ def test_html_with_fields(self):
             """
         )
 
+    def test_html_with_include_theme(self):
+        """ Test that the extracted HTML block's include_theme setting is serialized. """
+        course = CourseFactory.create(display_name='test course', run="Testing_course")
+        html_block = BlockFactory.create(
+            parent_location=course.location,
+            category="html",
+            display_name="Themed HTML Block",
+            include_theme=True,
+            data="🍔",
+        )
+        serialized = api.serialize_xblock_to_olx(html_block)
+        self.assertXmlEqual(
+            serialized.olx_str,
+            f"""
+            <html
+                copied_from_block="{str(html_block.location)}"
+                url_name="Themed_HTML_Block"
+                display_name="Themed HTML Block"
+                include_theme="true"
+            ><![CDATA[
+                🍔
+            ]]></html>
+            """
+        )
+
+    def test_html_without_include_theme_is_not_serialized(self):
+        """ Blocks that leave the setting unset must not gain the attribute. """
+        course = CourseFactory.create(display_name='test course', run="Testing_course")
+        html_block = BlockFactory.create(
+            parent_location=course.location,
+            category="html",
+            data="🍔",
+        )
+        serialized = api.serialize_xblock_to_olx(html_block)
+        assert "include_theme" not in serialized.olx_str
+
+    def test_html_with_include_theme_false_is_not_serialized(self):
+        """ A block carrying the default value must not gain the attribute either.
+
+        Syncing a library into a course copies every declared field into the
+        block's field data, so the setting arrives present and False rather than
+        absent. Writing it out would put include_theme="false" on every synced
+        HTML block.
+        """
+        course = CourseFactory.create(display_name='test course', run="Testing_course")
+        html_block = BlockFactory.create(
+            parent_location=course.location,
+            category="html",
+            data="🍔",
+            include_theme=False,
+        )
+        serialized = api.serialize_xblock_to_olx(html_block)
+        assert "include_theme" not in serialized.olx_str
+
     def test_export_sequential(self):
         """
         Export a sequential from the toy course, including all of its children.

pyproject.toml

@@ -293,6 +293,12 @@ constraint-dependencies = [
     "edx-enterprise==8.17.0",
     "djangorestframework<3.18",
 ]
+
+# TODO: drop this once xblocks-contrib ships a release carrying the Text
+# (HTML) block's include_theme field. Tracked by openedx/xblocks-core#308.
+[tool.uv.sources]
+xblocks-contrib = { git = "https://github.com/open-craft/xblocks-core.git", rev = "rpenido/text-xblock-include-theme" }
+
 [tool.edx_lint]
 uv_constraints = [
     # Date: 2025-10-07

requirements/edx/base.txt

@@ -1301,7 +1301,7 @@ xblock==6.3.3
 xblock-drag-and-drop-v2==5.1.1
 xblock-google-drive==0.8.2
 xblock-poll==1.16.1
-xblocks-contrib==1.0.6
+xblocks-contrib @ git+https://github.com/open-craft/xblocks-core.git@25702c61b6a9f3cf1afbc6e49a60790ca90f34c1
 xmlsec==1.3.14
     # via python3-saml
 xss-utils==1.0.0

requirements/edx/development.txt

@@ -1563,7 +1563,7 @@ xblock==6.3.3
 xblock-drag-and-drop-v2==5.1.1
 xblock-google-drive==0.8.2
 xblock-poll==1.16.1
-xblocks-contrib==1.0.6
+xblocks-contrib @ git+https://github.com/open-craft/xblocks-core.git@25702c61b6a9f3cf1afbc6e49a60790ca90f34c1
 xmlsec==1.3.14
     # via python3-saml
 xss-utils==1.0.0