fix: preserve widget state in HTML export

frontend/src/mount.tsx

@@ -20,12 +20,14 @@ import {
 import { Logger } from "@/utils/Logger";
 import { ErrorBoundary } from "./components/editor/boundary/ErrorBoundary";
 import { notebookAtom } from "./core/cells/cells";
+import type { UIElementId } from "./core/cells/ids";
 import { notebookStateFromSession } from "./core/cells/session";
 import {
   parseAppConfig,
   parseConfigOverrides,
   parseUserConfig,
 } from "./core/config/config-schema";
+import { UI_ELEMENT_REGISTRY } from "./core/dom/uiregistry";
 import { MarimoApp, preloadPage } from "./core/MarimoApp";
 import { type AppMode, initialModeAtom, viewStateAtom } from "./core/mode";
 import { cleanupAuthQueryParams } from "./core/network/auth";
@@ -341,6 +343,16 @@ function initStore(options: unknown) {
   if (notebook) {
     store.set(notebookAtom, notebook);
   }
+
+  // Restore widget state from session snapshot in static mode
+  if (isStaticNotebook()) {
+    const uiValues = parsedOptions.data.session?.ui_values;
+    if (uiValues) {
+      for (const [objectId, value] of Object.entries(uiValues)) {
+        UI_ELEMENT_REGISTRY.set(objectId as UIElementId, value);
+      }
+    }
+  }
 }
 
 /**

marimo/_schemas/generated/session.yaml

@@ -79,6 +79,10 @@ components:
           type: array
         metadata:
           $ref: '#/components/schemas/NotebookSessionMetadata'
+        ui_values:
+          additionalProperties: {}
+          nullable: true
+          type: object
         version:
           type: string
       required:

marimo/_schemas/session.py

@@ -98,6 +98,8 @@ class NotebookSessionV1(BaseDict):
     metadata: NotebookSessionMetadata
     # The cells in the notebook
     cells: list[Cell]
+    # Widget/UI element values at time of export
+    ui_values: Optional[dict[str, Any]]
 
     # In future, we may want to add
     # - variables

marimo/_session/state/serialize.py

@@ -163,6 +163,7 @@ def serialize_session_view(
             script_metadata_hash=script_metadata_hash,
         ),
         cells=cells,
+        ui_values=dict(view.ui_values),
     )
 
 

packages/openapi/src/session.ts

@@ -40,6 +40,9 @@ export interface components {
     NotebookSessionV1: {
       cells: components["schemas"]["Cell"][];
       metadata: components["schemas"]["NotebookSessionMetadata"];
+      ui_values?: {
+        [key: string]: unknown;
+      } | null;
       version: string;
     };
     StreamMediaOutput: {

tests/_session/state/snapshots/basic_session.json

@@ -18,5 +18,6 @@
       ],
       "console": []
     }
-  ]
-}
+  ],
+  "ui_values": {}
+}

tests/_session/state/snapshots/console_session.json

@@ -24,5 +24,6 @@
         }
       ]
     }
-  ]
+  ],
+  "ui_values": {}
 }

tests/_session/state/snapshots/error_session.json

@@ -18,5 +18,6 @@
       ],
       "console": []
     }
-  ]
-}
+  ],
+  "ui_values": {}
+}

tests/_session/state/snapshots/mime_bundle_session.json

@@ -21,5 +21,6 @@
       ],
       "console": []
     }
-  ]
-}
+  ],
+  "ui_values": {}
+}

tests/_session/state/snapshots/mixed_error_session.json

@@ -24,5 +24,6 @@
       ],
       "console": []
     }
-  ]
+  ],
+  "ui_values": {}
 }