feat: [AXIMST-490] display render errors

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

@@ -114,8 +114,8 @@ class ChildVerticalContainerSerializer(serializers.Serializer):
     actions = serializers.SerializerMethodField()
     user_partition_info = serializers.DictField()
     user_partitions = serializers.ListField()
-    has_validation_error = serializers.BooleanField()
-    validation_errors = MessageValidation(many=True)
+    validation_messages = MessageValidation(many=True)
+    render_error = serializers.CharField()
 
     def get_actions(self, obj):  # pylint: disable=unused-argument
         """

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

@@ -203,8 +203,8 @@ def test_children_content(self):
                 },
                 "user_partition_info": expected_user_partition_info,
                 "user_partitions": expected_user_partitions,
-                "has_validation_error": False,
-                "validation_errors": [],
+                "validation_messages": [],
+                "render_error": "",
             },
             {
                 "name": self.html_unit_second.display_name_with_default,
@@ -220,8 +220,8 @@ def test_children_content(self):
                 },
                 "user_partition_info": expected_user_partition_info,
                 "user_partitions": expected_user_partitions,
-                "has_validation_error": False,
-                "validation_errors": [],
+                "validation_messages": [],
+                "render_error": "",
             },
         ]
         self.assertEqual(response.data["children"], expected_response)
@@ -280,13 +280,8 @@ def test_validation_errors(self):
         response = self.client.get(url)
         children_response = response.data["children"]
 
-        # Check for an error in html_unit_first xblock
-        self.assertTrue(children_response[0]["has_validation_error"])
+        # Verify that html_unit_first access settings contradict its parent's access settings.
+        self.assertEqual(children_response[0]["validation_messages"][0]["type"], ValidationMessage.ERROR)
 
-        # Verify that html access settings contradict its parent's access settings.
-        validation = html_unit_first.validate()
-        self.assertEqual(len(validation.messages), 1)
-        self.assertEqual(validation.to_json()['messages'][0]['type'], ValidationMessage.ERROR)
-
-        # Check for an error in html_unit_second xblock
-        self.assertFalse(children_response[1]["has_validation_error"])
+        # Verify that html_unit_second has no validation messages.
+        self.assertFalse(children_response[1]["validation_messages"])

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

@@ -11,6 +11,7 @@
     get_user_partition_info,
     get_visibility_partition_info,
     get_validation_messages,
+    get_render_error,
 )
 from cms.djangoapps.contentstore.views.component import _get_item_in_course
 from cms.djangoapps.contentstore.xblock_storage_handlers.view_handlers import get_xblock
@@ -199,8 +200,8 @@ def get(self, request: Request, usage_key_string: str):
                         "can_delete": true,
                         "can_manage_tags": true,
                     }
-                    "has_validation_error": false,
-                    "validation_errors": [],
+                    "validation_messages": [],
+                    "render_error": "",
                 },
                 {
                     "name": "Text",
@@ -214,13 +215,13 @@ def get(self, request: Request, usage_key_string: str):
                         "can_delete": true,
                         "can_manage_tags": true,
                     },
-                    "has_validation_error": true,
-                    "validation_errors": [
+                    "validation_messages": [
                         {
                             "text": "This component's access settings contradict its parent's access settings.",
                             "type": "error"
                         }
-                    ]
+                    ],
+                    "render_error": "Unterminated control keyword: 'if' in file '../problem.html'",
                 },
             ],
             "is_published": false,
@@ -239,16 +240,17 @@ def get(self, request: Request, usage_key_string: str):
                 child_info = modulestore().get_item(child)
                 user_partition_info = get_visibility_partition_info(child_info, course=course)
                 user_partitions = get_user_partition_info(child_info, course=course)
-                validation_errors, has_validation_error = get_validation_messages(child_info)
+                validation_messages = get_validation_messages(child_info)
+                render_error = get_render_error(request, child_info)
 
                 children.append({
                     "name": child_info.display_name_with_default,
                     "block_id": child_info.location,
                     "block_type": child_info.location.block_type,
                     "user_partition_info": user_partition_info,
                     "user_partitions": user_partitions,
-                    "has_validation_error": has_validation_error,
-                    "validation_errors": validation_errors,
+                    "validation_messages": validation_messages,
+                    "render_error": render_error,
                 })
 
             is_published = not modulestore().has_changes(current_xblock)

cms/djangoapps/contentstore/utils.py

@@ -2149,11 +2149,51 @@ def get_validation_messages(xblock):
         xblock: The xblock object to validate.
 
     Returns:
-        tuple:
-            - validation_errors (list): A list of validation error messages.
-            - has_validation_error (bool): True if there are validation errors, False otherwise.
+        list: A list of validation error messages.
     """
     validation_json = xblock.validate().to_json()
-    validation_errors = validation_json['messages']
-    has_validation_error = bool(validation_errors)
-    return validation_errors, has_validation_error
+    return validation_json['messages']
+
+
+def get_render_error(request, xblock):
+    """
+    Checks if there are any rendering errors for a given block and return these.
+
+    Args:
+        request: WSGI request object
+        xblock: The xblock object to rendering.
+
+    Returns:
+        str: Error message which happened while rendering of xblock.
+    """
+    from cms.djangoapps.contentstore.views.preview import _load_preview_block
+    from xmodule.studio_editable import has_author_view
+    from xmodule.x_module import AUTHOR_VIEW, STUDENT_VIEW
+
+    def get_render_context(request, block):
+        """
+        Return a dict of the data needs for render of each block.
+        """
+        can_edit = has_studio_write_access(request.user, block.usage_key.course_key)
+
+        return {
+            "is_unit_page": False,
+            "can_edit": can_edit,
+            "root_xblock": xblock,
+            "reorderable_items": set(),
+            "paging": None,
+            "force_render": None,
+            "item_url": "/container/{block.location}",
+            "tags_count_map": {},
+        }
+
+    render_error = ""
+    try:
+        block = _load_preview_block(request, xblock)
+        preview_view = AUTHOR_VIEW if has_author_view(block) else STUDENT_VIEW
+        render_context = get_render_context(request, block)
+        block.render(preview_view, render_context)
+    except Exception as exc:  # pylint: disable=broad-except
+        render_error = str(exc)
+
+    return render_error