Apply code review comments and fix tests

cms/djangoapps/contentstore/views/component.py

@@ -11,8 +11,8 @@ from django.conf import settings
 from xmodule.modulestore.exceptions import ItemNotFoundError
 from edxmako.shortcuts import render_to_response
 
+from xmodule.modulestore import ModuleStoreEnum
 from xmodule.modulestore.django import modulestore
-from xmodule.modulestore import LegacyPublishState
 
 from xblock.core import XBlock
 from xblock.django.request import webob_to_django_response, django_to_webob_request
@@ -21,7 +21,7 @@ from xblock.fields import Scope
 from xblock.plugin import PluginMissingError
 from xblock.runtime import Mixologist
 
-from contentstore.utils import get_lms_link_for_item, compute_publish_state
+from contentstore.utils import get_lms_link_for_item
 from contentstore.views.helpers import get_parent_xblock, is_unit, xblock_type_display_name
 from contentstore.views.item import create_xblock_info
 
@@ -100,8 +100,8 @@ def subsection_handler(request, usage_key_string):
         can_view_live = False
         subsection_units = item.get_children()
         for unit in subsection_units:
-            state = compute_publish_state(unit)
-            if state in (LegacyPublishState.public, LegacyPublishState.draft):
+            has_published = modulestore().has_item(unit.location, revision=ModuleStoreEnum.RevisionOption.published_only)
+            if has_published:
                 can_view_live = True
                 break
 
@@ -178,6 +178,10 @@ def container_handler(request, usage_key_string):
         # about the block's ancestors and siblings for use by the Unit Outline.
         xblock_info = create_xblock_info(xblock, include_ancestor_info=is_unit_page)
 
+        # On the unit page only, add 'has_changes' to indicate when there are changes that can be discarded.
+        if is_unit_page:
+            xblock_info['has_changes'] = modulestore().has_changes(xblock.location)
+
         # Create the link for preview.
         preview_lms_base = settings.FEATURES.get('PREVIEW_LMS_BASE')
         # need to figure out where this item is in the list of children as the