feat: support optional completion for individual XBlocks

Author: Agrendalath

common/templates/xblock_wrapper.html

@@ -1,7 +1,11 @@
 ## xss-lint: disable=mako-missing-default
 <%!
 from openedx.core.djangolib.js_utils import dump_js_escaped_json
+from django.utils.translation import gettext as _
 %>
+% if 'data-is-optional="True"' in data_attributes:
+  <span class="optional-completion-badge text-uppercase border badge badge-light mb-3">${_("Optional")}</span>
+% endif
 <div class="${' '.join(classes) | n, decode.utf8}" ${data_attributes}>
 % if js_init_parameters:
   <script type="json/xblock-args" class="xblock-json-init-args">

openedx/core/lib/xblock_utils/__init__.py

@@ -23,6 +23,7 @@
 from web_fragments.fragment import Fragment
 from xblock.core import XBlock
 from xblock.exceptions import InvalidScopeError
+from xblock.fields import Scope
 from xblock.scorable import ScorableXBlockMixin
 
 from common.djangoapps import static_replace
@@ -141,6 +142,13 @@ def wrap_xblock(
     if block.name:
         data['name'] = block.name
 
+    # We check whether the block is explicitly set as optional because this information is already displayed for units
+    # in the Learning MFE.
+    has_children = getattr(block, "children", False)
+    is_explicitly_optional = block.get_explicitly_set_fields_by_scope(Scope.settings).get('optional_completion', False)
+    if view != STUDIO_VIEW and not has_children and is_explicitly_optional:
+        data['is-optional'] = getattr(block, 'optional_completion', False)
+
     template_context = {
         'content': block.display_name if display_name_only else frag.content,
         'classes': css_classes,

xmodule/tests/test_xml_block.py

@@ -236,7 +236,7 @@ def test_display_name_field(self):
         editable_fields = self.get_xml_editable_fields(DictFieldData({}))
         # Tests that the xblock fields (currently tags and name) get filtered out.
         # Also tests that xml_attributes is filtered out of XmlMixin.
-        assert 1 == len(editable_fields), editable_fields
+        assert 2 == len(editable_fields), editable_fields
         self.assert_field_values(
             editable_fields, 'display_name', XModuleMixin.display_name,
             explicitly_set=False, value=None, default_value=None
@@ -253,7 +253,7 @@ def test_override_default(self):
     def test_integer_field(self):
         block = self.get_block(DictFieldData({'max_attempts': '7'}))
         editable_fields = block.editable_metadata_fields
-        assert 8 == len(editable_fields)
+        assert 9 == len(editable_fields)
         self.assert_field_values(
             editable_fields, 'max_attempts', TestFields.max_attempts,
             explicitly_set=True, value=7, default_value=1000, type='Integer',

xmodule/x_module.py

@@ -651,6 +651,18 @@ def editable_metadata_fields(self):
 
             metadata_fields[field.name] = self._create_metadata_editor_info(field)
 
+        # The `optional_completion` field can be either explicitly set or inherited from the parent.
+        # While we could query the parent's field, there is a special case that cannot be supported with the platform's
+        # completion calculations that count the completed units instead of individual XBlocks.
+        # If this field is explicitly set to False, then we want to show it in the metadata editor so that the author
+        # can reset it to the default inherited value.
+        if "optional_completion" in self.fields:
+            has_explicitly_set_optional_completion = self.fields['optional_completion'].is_set_on(self)
+            if not self.optional_completion or has_explicitly_set_optional_completion:
+                metadata_fields["optional_completion"] = self._create_metadata_editor_info(
+                    self.fields["optional_completion"]
+                )
+
         return metadata_fields
 
     def _create_metadata_editor_info(self, field):