fix: problem block could not be used with versioned handler URls

openedx/core/djangoapps/xblock/api.py

@@ -299,9 +299,9 @@ def get_handler_url(
         'secure_token': secure_token,
         'handler_name': handler_name,
     }
-    path = reverse('xblock_api:xblock_handler', kwargs=kwargs)
     if version != LatestVersion.AUTO:
-        path += "?version=" + (str(version) if isinstance(version, int) else version.value)
+        kwargs["version"] = str(version) if isinstance(version, int) else version.value
+    path = reverse('xblock_api:xblock_handler', kwargs=kwargs)
 
     # We must return an absolute URL. We can't just use
     # rest_framework.reverse.reverse to get the absolute URL because this method

openedx/core/djangoapps/xblock/rest_api/urls.py

@@ -10,25 +10,31 @@
 # urls_studio and urls_lms, and/or the views could be likewise duplicated.
 app_name = 'openedx.core.djangoapps.xblock.rest_api'
 
+block_endpoints = [
+    # get metadata about an XBlock:
+    path('', views.block_metadata),
+    # get/post full json fields of an XBlock:
+    path('fields/', views.BlockFieldsView.as_view()),
+    # render one of this XBlock's views (e.g. student_view)
+    re_path(r'^view/(?P<view_name>[\w\-]+)/$', views.render_block_view),
+    # get the URL needed to call this XBlock's handlers
+    re_path(r'^handler_url/(?P<handler_name>[\w\-]+)/$', views.get_handler_url),
+    # call one of this block's handlers
+    re_path(
+        r'^handler/(?P<user_id>\w+)-(?P<secure_token>\w+)/(?P<handler_name>[\w\-]+)/(?P<suffix>.+)?$',
+        views.xblock_handler,
+        name='xblock_handler',
+    ),
+    # API endpoints related to a specific version of this XBlock:
+]
+
 urlpatterns = [
     path('api/xblock/v2/', include([
-        path('xblocks/<str:usage_key_str>/', include([
-            # get metadata about an XBlock:
-            path('', views.block_metadata),
-            # get/post full json fields of an XBlock:
-            path('fields/', views.BlockFieldsView.as_view()),
-            # render one of this XBlock's views (e.g. student_view)
-            re_path(r'^view/(?P<view_name>[\w\-]+)/$', views.render_block_view),
-            # get the URL needed to call this XBlock's handlers
-            re_path(r'^handler_url/(?P<handler_name>[\w\-]+)/$', views.get_handler_url),
-            # call one of this block's handlers
-            re_path(
-                r'^handler/(?P<user_id>\w+)-(?P<secure_token>\w+)/(?P<handler_name>[\w\-]+)/(?P<suffix>.+)?$',
-                views.xblock_handler,
-                name='xblock_handler',
-            ),
-        ])),
+        # This pattern with the version must come first so '@' isn't included in usage_key_str below
+        path(r'xblocks/<str:usage_key_str>@<str:version>/', include(block_endpoints)),
+        path(r'xblocks/<str:usage_key_str>/', include(block_endpoints)),
     ])),
+    # Non-API views (these return HTML, not JSON):
     path('xblocks/v2/<str:usage_key_str>/', include([
         # render one of this XBlock's views (e.g. student_view) for embedding in an iframe
         # NOTE: this endpoint is **unstable** and subject to changes after Sumac

openedx/core/djangoapps/xblock/rest_api/views.py

@@ -58,7 +58,7 @@ def parse_version_request(version_str: str | None) -> LatestVersion | int:
         return int(version_str)
     except ValueError:
         raise serializers.ValidationError(  # pylint: disable=raise-missing-from
-            "Invalid version specifier '{version_str}'. Expected 'draft', 'published', or an integer."
+            f"Invalid version specifier '{version_str}'. Expected 'draft', 'published', or an integer."
         )
 
 
@@ -184,7 +184,7 @@ def get_handler_url(request, usage_key_str, handler_name):
 # and https://github.com/openedx/XBlock/pull/383 for context.
 @csrf_exempt
 @xframe_options_exempt
-def xblock_handler(request, user_id, secure_token, usage_key_str, handler_name, suffix=None):
+def xblock_handler(request, user_id, secure_token, usage_key_str, handler_name, suffix=None, version=None):
     """
     Run an XBlock's handler and return the result
 
@@ -232,7 +232,7 @@ def xblock_handler(request, user_id, secure_token, usage_key_str, handler_name,
 
     request_webob = DjangoWebobRequest(request)  # Convert from django request to the webob format that XBlocks expect
 
-    block = load_block(usage_key, user, version=parse_version_request(request.GET.get("version")))
+    block = load_block(usage_key, user, version=parse_version_request(version))
     # Run the handler, and save any resulting XBlock field value changes:
     response_webob = block.handle(handler_name, request_webob, suffix)
     response = webob_to_django_response(response_webob)

openedx/core/djangoapps/xblock/runtime/runtime.py

@@ -156,7 +156,14 @@ def handler_url(self, block, handler_name: str, suffix='', query='', thirdparty=
 
         # Note: it's important that we call handlers based on the same version of the block
         # (draft block -> draft data available to handler; published block -> published data available to handler)
-        kwargs = {"version": block._runtime_requested_version} if hasattr(block, "_runtime_requested_version") else {}  # pylint: disable=protected-access
+        kwargs = {}
+        if hasattr(block, "_runtime_requested_version"):  # pylint: disable=protected-access
+            if self.authored_data_mode == AuthoredDataMode.DEFAULT_DRAFT:
+                default_version = LatestVersion.DRAFT
+            else:
+                default_version = LatestVersion.PUBLISHED
+            if block._runtime_requested_version != default_version:  # pylint: disable=protected-access
+                kwargs["version"] = block._runtime_requested_version  # pylint: disable=protected-access
         url = self.handler_url_fn(block.usage_key, handler_name, self.user, **kwargs)
         if suffix:
             if not url.endswith('/'):