Test PR

xblock/cds_init_args_mixin.py

@@ -0,0 +1,29 @@
+"""
+Minimal mixin for Split Mongo: pops ``cds_init_args`` and exposes ``get_cds_init_args``.
+
+``XModuleMixin`` does the same; use this when ``XModuleMixin`` is omitted from the
+runtime mixin list so ``construct_xblock_from_class(..., cds_init_args=...)`` still works.
+"""
+
+
+class CdsInitArgsMixin:
+    """
+    Initialization data used by SplitModuleStoreRuntime to defer FieldData initialization.
+
+    Mirrors the ``cds_init_args`` handling in ``xmodule.x_module.XModuleMixin`` without
+    pulling in the rest of XModule behavior.
+    """
+
+    def __init__(self, *args, **kwargs):
+        self._cds_init_args = kwargs.pop("cds_init_args", None)
+        super().__init__(*args, **kwargs)
+
+    def get_cds_init_args(self):
+        """Get initialization data used by SplitModuleStoreRuntime to defer FieldData initialization."""
+        if self._cds_init_args is None:
+            raise KeyError("cds_init_args was not provided for this XBlock")
+        if self._cds_init_args is False:
+            raise RuntimeError("Tried to get SplitModuleStoreRuntime cds_init_args twice for the same XBlock.")
+        args = self._cds_init_args
+        self._cds_init_args = False
+        return args

xblock/runtime.py

@@ -19,6 +19,7 @@
 
 from web_fragments.fragment import Fragment
 
+from xblock.cds_init_args_mixin import CdsInitArgsMixin
 from xblock.core import XBlock, XBlockAside, XML_NAMESPACES
 from xblock.fields import Field, BlockScope, Scope, ScopeIds, UserScope
 from xblock.field_data import FieldData
@@ -1273,6 +1274,24 @@ def mix(self, cls):
         else:
             base_class = cls
             mixins = self._mixins
+            if (
+                hasattr(base_class, "__name__")
+                and base_class.__name__ == "VideoBlock"
+                and getattr(base_class, "is_extracted", False)
+            ):
+                def _is_xmodule_mixin(mixin):
+                    return (
+                        getattr(mixin, "__name__", None) == "XModuleMixin"
+                        or f"{getattr(mixin, '__module__', '')}.{getattr(mixin, '__name__', '')}"
+                        == "xmodule.x_module.XModuleMixin"
+                    )
+
+                # Split Mongo passes ``cds_init_args`` into the block constructor; XModuleMixin pops it.
+                # If we drop XModuleMixin, substitute this minimal mixin in the same MRO slot.
+                mixins = tuple(
+                    CdsInitArgsMixin if _is_xmodule_mixin(m) else m
+                    for m in mixins
+                )
 
         mixin_key = (base_class, mixins)