Merge pull request #3373 from plotly/fix/layout-list-persistence

Fix layout as list and persistence

Author: T4rk1n

CHANGELOG.md

@@ -12,6 +12,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 - [#3353](https://github.com/plotly/dash/pull/3353) Support pattern-matching/dict ids in `dcc.Loading` `target_components`
 - [#3371](https://github.com/plotly/dash/pull/3371) Fix allow_optional triggering a warning for not found input.
 - [#3379](https://github.com/plotly/dash/pull/3379) Fix dcc.Graph backward compatibility with dash 2.0 for ddk.Graph
+- [#3373](https://github.com/plotly/dash/pull/3373) Fix layout as list and persistence.
 
 # [3.1.1] - 2025-06-29
 

dash/dash-renderer/src/persistence.js

@@ -70,6 +70,7 @@ import {createAction} from 'redux-actions';
 
 import Registry from './registry';
 import {stringifyId} from './actions/dependencies';
+import {isDryComponent} from './wrapper/wrapping';
 
 export const storePrefix = '_dash_persistence.';
 
@@ -361,10 +362,11 @@ export function recordUiEdit(layout, newProps, dispatch) {
  * callbacks) to apply previously-stored UI edits to components
  */
 export function applyPersistence(layout, dispatch) {
-    if (type(layout) !== 'Object' || !layout.props) {
-        return layout;
+    if (Array.isArray(layout)) {
+        return layout.map(lay =>
+            isDryComponent(lay) ? persistenceMods(lay, lay, [], dispatch) : lay
+        );
     }
-
     return persistenceMods(layout, layout, [], dispatch);
 }
 

tests/integration/renderer/test_persistence.py

@@ -560,3 +560,45 @@ def update_container2(n_clicks):
     # persistenceTransforms should return upper case strings
     dash_duo.wait_for_text_to_equal("#component-propName", "ALPACA")
     dash_duo.wait_for_text_to_equal("#component-propPart", "ARTICHOKE")
+
+
+def test_rdps014_layout_as_list(dash_duo):
+    # testing persistence with layout as list
+    app = dash.Dash(__name__)
+    app.layout = [
+        dcc.Input(id="input-1", value="initial", persistence=True),
+        html.Div(id="output-1"),
+        dcc.Input(id="input-2", value="second", persistence=True),
+        html.Div(id="output-2"),
+    ]
+
+    @app.callback(Output("output-1", "children"), [Input("input-1", "value")])
+    def update_output_1(value):
+        return f"Output 1: {value}"
+
+    @app.callback(Output("output-2", "children"), [Input("input-2", "value")])
+    def update_output_2(value):
+        return f"Output 2: {value}"
+
+    dash_duo.start_server(app)
+
+    # Check initial values
+    dash_duo.wait_for_text_to_equal("#output-1", "Output 1: initial")
+    dash_duo.wait_for_text_to_equal("#output-2", "Output 2: second")
+
+    # Change the input values
+    dash_duo.clear_input("#input-1")
+    dash_duo.find_element("#input-1").send_keys("changed1")
+    dash_duo.clear_input("#input-2")
+    dash_duo.find_element("#input-2").send_keys("changed2")
+
+    # Verify changes
+    dash_duo.wait_for_text_to_equal("#output-1", "Output 1: changed1")
+    dash_duo.wait_for_text_to_equal("#output-2", "Output 2: changed2")
+
+    # Reload the page to test persistence
+    dash_duo.wait_for_page()
+
+    # Check that persisted values are restored
+    dash_duo.wait_for_text_to_equal("#output-1", "Output 1: changed1")
+    dash_duo.wait_for_text_to_equal("#output-2", "Output 2: changed2")