How to refresh tree grid selection?

ao92 · April 28, 2026, 11:01am

I am currently running into this bug:

[Grid] Selection not updated after DP refresh

opened 06:53AM - 07 May 24 UTC

enhancement vaadin-grid needs research

### Description This is a follow up of #1265. The issue is the same as in the… described ticket. When calling one of the refresh methods of a Grid's DataProvider, the selection inside the grid still refers to the old objects. ### Expected outcome The grid's selected items should be updated, when the data provider is refreshed, so that calling "getSelectedItems" refers to the same objects, that were returned from the DataProvider. **Lazy loading and multi select performance** This featue can lead to performance issues, when using lazy loading and multi select, for instance when selecting a huge amount of items. To give devs the possibility to react on this problem, it should be possible on multi select mode to 1. deactivate it explicitly (as it is now, so the dev has full control over it) 2. refresh only selected items, when they are fetched 3. refresh explicitly all selected items for instance via the selection model, the grid or the data provider (I would say the grid selection model should be the most fitting one?). Something like ``` Multi#setUpdateSelectedItemsOnRefreshMode() enum UpdateSelectedItemsOnRefreshMode { NEVER, ONLY_FETCHED, ALL } ``` From my side there is no request, which should be the default. I think the only fetched is maybe the most fitting for most use cases. Case 2 means, that, when for instance all items are selected, that when showing the first 50 items, only those 50 items are updated and the remaining ones are still outdated. When triggering the next fetch by scrolling down, the next 50 items, that are fetched also will update the respective items in the grid's selection. ### Minimal reproducible example ```java @Route("") public class GridOutdatedSelectionIssueView extends VerticalLayout { private final Grid<Data> grid; private List<Data> BACKEND; private int iteration; public GridOutdatedSelectionIssueView() { initData(); grid = new Grid<>(Data.class); grid.setItems(DataProvider.fromCallbacks( query -> BACKEND.stream() .skip(query.getOffset()) .limit(query.getLimit()), query -> BACKEND.size() )); Button reset = new Button("Reset", event -> { initData(); // simulate data has changed in the backend grid.getDataProvider().refreshAll(); showSelection(); }); Button show = new Button("Show", event -> showSelection()); Button mode = new Button("Switch Selection Mode", event -> { if (grid.getSelectionModel() instanceof SelectionModel.Single<?, ?>) { grid.setSelectionMode(Grid.SelectionMode.MULTI); } else { grid.setSelectionMode(Grid.SelectionMode.SINGLE); } }); add(new HorizontalLayout(reset, show, mode), grid); setFlexGrow(1, grid); setHorizontalComponentAlignment(Alignment.STRETCH, grid); } private void showSelection() { Set<Data> selectedItems = grid.getSelectedItems(); String collect = selectedItems.stream().map(Data::getName).collect(Collectors.joining("; ")); Notification.show(!collect.isEmpty() ? collect : "No items selected"); } public void initData() { BACKEND = LongStream.range(0, 200) .mapToObj(id -> new Data(id, "Item " + id + " (iteration " + iteration + ")")) .toList(); iteration++; } @RequiredArgsConstructor @Getter @EqualsAndHashCode(of = "id") public static class Data { private final long id; private final String name; } } ``` ### Steps to reproduce 1. Add the sample code to your Vaadin app 2. The list should show items incl. iteration 0 3. Select something. Click "Show". The notification should show the correct item. 4. Click "Reset". The items in the grid are refreshed and show an increased iteration counter. The notification still shows the old item names. 5. Click "Show" without changing the selection. The notification still shows the old item names. 6. Select a different item and click "Show" again. The notification now shows the correct item name. 7. Click "Switch Selection Mode". Repeat 3-6 to show the issue for multi select ### Environment Vaadin version(s): 24.3.10 ### Browsers _No response_

After calling refreshAll(), selected items remain selected(as they should), but there is outdated data in the selection afterwards.

Now i want to write a workaround for that by manually updating the selection. I am using this:

grid.asMultiSelect().setValue(items);

Unfortunately, this does not work, because internally items already inside the selection are filtered before performing the actual update of the selection model.

So, is there an API to achieve this? Please consider this:

Deselect + Select is not an option, because that would trigger the selection event twice and update other SelectionGrids. SelectionGrid does not handle multiple updates at the same time very well. It would be fine if the selection event is not triggered at all.

sissbruecker · April 28, 2026, 1:12pm

There is no built-in support for that at the moment. All the selection state of the component tells you is which items are selected, based on their identity. It does not guarantee that the items data is up to date. Implementing that would also present some challenges when it comes to lazy loading data providers, as the component would need to fetch all data in order to map old to new items. Since that is a no-go, that would likely require additional API in data providers that would allow users to implement such a mapping function.

Which is basically what you can do right now as a workaround. Take the selected items from the grid and match them against your current data based on their identity to get a “live selection” with up-to-date data. If you need to call that function often, and matching items is a slow operation, consider caching the live selection data and invalidate the cache on selection change events.