feat: [FC-0044] XBlock's children API as DRF (openedx#34055)

* feat: XBlock's children API as DRF

* fix: 500 error appears if user adds a Content Experiment

* fix: wrap into try/except block getting icon for xblock (#2509)

* fix: wrap into try/except block getting icon for xblock

* fix: revision after review

cms/djangoapps/contentstore/rest_api/v1/mixins.py

@@ -2,10 +2,16 @@
 Common mixins for module.
 """
 import json
+import logging
 from unittest.mock import patch
 
+from django.http import Http404
+from opaque_keys import InvalidKeyError
+from opaque_keys.edx.keys import UsageKey
 from rest_framework import status
 
+log = logging.getLogger(__name__)
+
 
 class PermissionAccessMixin:
     """
@@ -30,7 +36,7 @@ def test_permissions_unauthenticated(self):
         self.assertEqual(error, "Authentication credentials were not provided.")
         self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
 
-    @patch.dict('django.conf.settings.FEATURES', {'DISABLE_ADVANCED_SETTINGS': True})
+    @patch.dict("django.conf.settings.FEATURES", {"DISABLE_ADVANCED_SETTINGS": True})
     def test_permissions_unauthorized(self):
         """
         Test that an error is returned if the user is unauthorised.
@@ -40,3 +46,20 @@ def test_permissions_unauthorized(self):
         error = self.get_and_check_developer_response(response)
         self.assertEqual(error, "You do not have permission to perform this action.")
         self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+
+
+class ContainerHandlerMixin:
+    """
+    A mixin providing common functionality for container handler views.
+    """
+
+    def get_object(self, usage_key_string):
+        """
+        Get an object by usage-id of the block
+        """
+        try:
+            usage_key = UsageKey.from_string(usage_key_string)
+            return usage_key
+        except InvalidKeyError as err:
+            log.error(f"Invalid usage key: {usage_key_string}", exc_info=True)
+            raise Http404(f"Object not found for usage key: {usage_key_string}") from err

cms/djangoapps/contentstore/rest_api/v1/serializers/__init__.py

@@ -21,4 +21,4 @@
     VideoUsageSerializer,
     VideoDownloadSerializer
 )
-from .vertical_block import ContainerHandlerSerializer
+from .vertical_block import ContainerHandlerSerializer, VerticalContainerSerializer

cms/djangoapps/contentstore/rest_api/v1/serializers/vertical_block.py

@@ -91,3 +91,21 @@ def get_assets_url(self, obj):
                 "assets_handler", kwargs={"course_key_string": context_course.id}
             )
         return None
+
+
+class ChildVerticalContainerSerializer(serializers.Serializer):
+    """
+    Serializer for representing a xblock child of vertical container.
+    """
+
+    name = serializers.CharField(source="display_name_with_default")
+    block_id = serializers.CharField(source="location")
+
+
+class VerticalContainerSerializer(serializers.Serializer):
+    """
+    Serializer for representing a vertical container with state and children.
+    """
+
+    children = ChildVerticalContainerSerializer(many=True)
+    is_published = serializers.BooleanField()

cms/djangoapps/contentstore/rest_api/v1/urls.py

@@ -21,7 +21,8 @@
     ProctoringErrorsView,
     HelpUrlsView,
     VideoUsageView,
-    VideoDownloadView
+    VideoDownloadView,
+    VerticalContainerView,
 )
 
 app_name = 'v1'
@@ -107,6 +108,11 @@
         ContainerHandlerView.as_view(),
         name="container_handler"
     ),
+    re_path(
+        fr'^container/vertical/{settings.USAGE_KEY_PATTERN}/children$',
+        VerticalContainerView.as_view(),
+        name="container_vertical"
+    ),
 
     # Authoring API
     # Do not use under v1 yet (Nov. 23). The Authoring API is still experimental and the v0 versions should be used

cms/djangoapps/contentstore/rest_api/v1/views/__init__.py

@@ -15,4 +15,4 @@
     VideoDownloadView
 )
 from .help_urls import HelpUrlsView
-from .vertical_block import ContainerHandlerView
+from .vertical_block import ContainerHandlerView, VerticalContainerView

cms/djangoapps/contentstore/rest_api/v1/views/tests/test_vertical_block.py

@@ -5,63 +5,174 @@
 from rest_framework import status
 
 from cms.djangoapps.contentstore.tests.utils import CourseTestCase
-from xmodule.modulestore.django import modulestore  # lint-amnesty, pylint: disable=wrong-import-order
-from xmodule.modulestore.tests.factories import BlockFactory  # lint-amnesty, pylint: disable=wrong-import-order
+from xmodule.modulestore.django import (
+    modulestore,
+)  # lint-amnesty, pylint: disable=wrong-import-order
+from xmodule.modulestore.tests.factories import (
+    BlockFactory,
+)  # lint-amnesty, pylint: disable=wrong-import-order
+from xmodule.modulestore import (
+    ModuleStoreEnum,
+)  # lint-amnesty, pylint: disable=wrong-import-order
 
 
-class ContainerHandlerViewTest(CourseTestCase):
+class BaseXBlockContainer(CourseTestCase):
     """
-    Unit tests for the ContainerHandlerView.
+    Base xBlock container handler.
+
+    Contains common function for processing course xblocks.
     """
 
+    view_name = None
+
     def setUp(self):
         super().setUp()
-        self.chapter = BlockFactory.create(
-            parent=self.course, category="chapter", display_name="Week 1"
-        )
-        self.sequential = BlockFactory.create(
-            parent=self.chapter, category="sequential", display_name="Lesson 1"
-        )
-        self.vertical = self._create_block(self.sequential, "vertical", "Unit")
-
         self.store = modulestore()
-        self.store.publish(self.vertical.location, self.user.id)
+        self.setup_xblock()
 
-    def _get_reverse_url(self, location):
+    def setup_xblock(self):
         """
-        Creates url to current handler view api
+        Set up XBlock objects for testing purposes.
+
+        This method creates XBlock objects representing a course structure with chapters,
+        sequentials, verticals and others.
         """
-        return reverse(
-            "cms.djangoapps.contentstore:v1:container_handler",
-            kwargs={"usage_key_string": location},
+        self.chapter = self.create_block(
+            parent=self.course.location,
+            category="chapter",
+            display_name="Week 1",
+        )
+
+        self.sequential = self.create_block(
+            parent=self.chapter.location,
+            category="sequential",
+            display_name="Lesson 1",
+        )
+
+        self.vertical = self.create_block(self.sequential.location, "vertical", "Unit")
+
+        self.html_unit_first = self.create_block(
+            parent=self.vertical.location,
+            category="html",
+            display_name="Html Content 1",
+        )
+
+        self.html_unit_second = self.create_block(
+            parent=self.vertical.location,
+            category="html",
+            display_name="Html Content 2",
         )
 
-    def _create_block(self, parent, category, display_name, **kwargs):
+    def create_block(self, parent, category, display_name, **kwargs):
         """
         Creates a block without publishing it.
         """
         return BlockFactory.create(
-            parent=parent,
+            parent_location=parent,
             category=category,
             display_name=display_name,
+            modulestore=self.store,
             publish_item=False,
             user_id=self.user.id,
-            **kwargs
+            **kwargs,
+        )
+
+    def get_reverse_url(self, location):
+        """
+        Creates url to current view api name
+        """
+        return reverse(
+            f"cms.djangoapps.contentstore:v1:{self.view_name}",
+            kwargs={"usage_key_string": location},
         )
 
+    def publish_item(self, store, item_location):
+        """
+        Publish the item at the given location
+        """
+        with store.branch_setting(ModuleStoreEnum.Branch.draft_preferred):
+            store.publish(item_location, ModuleStoreEnum.UserID.test)
+
+
+class ContainerHandlerViewTest(BaseXBlockContainer):
+    """
+    Unit tests for the ContainerHandlerView.
+    """
+
+    view_name = "container_handler"
+
     def test_success_response(self):
         """
         Check that endpoint is valid and success response.
         """
-        url = self._get_reverse_url(self.vertical.location)
+        url = self.get_reverse_url(self.vertical.location)
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
+    def test_not_valid_usage_key_string(self):
+        """
+        Check that invalid 'usage_key_string' raises Http404.
+        """
+        usage_key_string = (
+            "i4x://InvalidOrg/InvalidCourse/vertical/static/InvalidContent"
+        )
+        url = self.get_reverse_url(usage_key_string)
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 404)
+
+
+class ContainerVerticalViewTest(BaseXBlockContainer):
+    """
+    Unit tests for the ContainerVerticalViewTest.
+    """
+
+    view_name = "container_vertical"
+
+    def test_success_response(self):
+        """
+        Check that endpoint returns valid response data.
+        """
+        url = self.get_reverse_url(self.vertical.location)
         response = self.client.get(url)
         self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(len(response.data["children"]), 2)
+        self.assertFalse(response.data["is_published"])
+
+    def test_xblock_is_published(self):
+        """
+        Check that published xBlock container returns.
+        """
+        self.publish_item(self.store, self.vertical.location)
+        url = self.get_reverse_url(self.vertical.location)
+        response = self.client.get(url)
+        self.assertTrue(response.data["is_published"])
+
+    def test_children_content(self):
+        """
+        Check that returns valid response with children of vertical container.
+        """
+        url = self.get_reverse_url(self.vertical.location)
+        response = self.client.get(url)
+
+        expected_response = [
+            {
+                "name": self.html_unit_first.display_name_with_default,
+                "block_id": str(self.html_unit_first.location),
+            },
+            {
+                "name": self.html_unit_second.display_name_with_default,
+                "block_id": str(self.html_unit_second.location),
+            },
+        ]
+        self.assertEqual(response.data["children"], expected_response)
 
     def test_not_valid_usage_key_string(self):
         """
         Check that invalid 'usage_key_string' raises Http404.
         """
-        usage_key_string = "i4x://InvalidOrg/InvalidCourse/vertical/static/InvalidContent"
-        url = self._get_reverse_url(usage_key_string)
+        usage_key_string = (
+            "i4x://InvalidOrg/InvalidCourse/vertical/static/InvalidContent"
+        )
+        url = self.get_reverse_url(usage_key_string)
         response = self.client.get(url)
         self.assertEqual(response.status_code, 404)