FluentDataGrid Does not refresh after items updated

[Doc415]

Hey. I am new to Fluent UI and having some difficulty with datagrid.
I have a FluentDataGrid to show list of model. I want to filter the items according to a property. When i query and update the items and use updateDataAsync() method, datagrid does not update and at the end of the method browser gives error.
How am i suppose to update DataGrid when items list changes?

This is my datagrid:

<FluentDataGrid @ref="@MealGrid" TGridItem="Meal" Items="@FilteredMeals" ShowHover="true" ResizableColumns=true Pagination="@pagination" GridTemplateColumns="0.2fr 0.1fr 0.1fr 0.6fr 0.2fr 0.2fr" RowClass="@rowClass" RowStyle="@rowStyle" Style="height: auto;overflow:auto;">

this is the method triggered for filtering:

  private async Task FilterMeals()
  {
      IQueryable<Meal> tempMeals;
      if (!string.IsNullOrEmpty(searchValue))
          tempMeals = FilteredMeals.Where(x => x.Foods != null && x.Foods.Any(food => food.Name.ToLower().Contains(searchValue.ToLower())));
      else
          tempMeals = meals;

      if (tempMeals != meals && tempMeals!=null)
          FilteredMeals = tempMeals;

      searchValue = null;
      mealFilter = "All";
      await MealGrid.RefreshDataAsync();
         
  }

i have debugged the method and the query is working well. FileteredMeals (which datagrid uses as items) updates according to filtering. But the grid does not update.

[vnbaaij]

Have you tried to add a StateHasChanged() call at the end of your FilterMeals method?

[Doc415]

Yes. Still it does not work. I got this error on console:

warn: Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer[100] Unhandled exception rendering component: Object reference not set to an instance of an object. System.NullReferenceException: Object reference not set to an instance of an object. at lambda_method245(Closure, Food) at System.Linq.Enumerable.Any[TSource](IEnumerable1 source, Func2 predicate) at lambda_method244(Closure, Meal) at System.Linq.Enumerable.WhereListIterator1.GetCount(Boolean onlyIfCheap)
at System.Linq.EnumerableExecutor1.Execute() at System.Linq.EnumerableQuery1.System.Linq.IQueryProvider.Execute[TElement](Expression expression)
at Microsoft.FluentUI.AspNetCore.Components.FluentDataGrid1.ResolveItemsRequestAsync(GridItemsProviderRequest1 request) in //src/Core/Components/DataGrid/FluentDataGrid.razor.cs:line 522
at Microsoft.FluentUI.AspNetCore.Components.FluentDataGrid1.RefreshDataCoreAsync() in /_/src/Core/Components/DataGrid/FluentDataGrid.razor.cs:line 441 at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task) fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111] Unhandled exception in circuit 'YuPjO_pwzTrlaOleTazA0R2U1tw6JTFjCokl3fsR85Q'. System.NullReferenceException: Object reference not set to an instance of an object. at lambda_method245(Closure, Food) at System.Linq.Enumerable.Any[TSource](IEnumerable1 source, Func2 predicate) at lambda_method244(Closure, Meal) at System.Linq.Enumerable.WhereListIterator1.GetCount(Boolean onlyIfCheap)
at System.Linq.EnumerableExecutor1.Execute() at System.Linq.EnumerableQuery1.System.Linq.IQueryProvider.Execute[TElement](Expression expression)
at Microsoft.FluentUI.AspNetCore.Components.FluentDataGrid1.ResolveItemsRequestAsync(GridItemsProviderRequest1 request) in //src/Core/Components/DataGrid/FluentDataGrid.razor.cs:line 522
at Microsoft.FluentUI.AspNetCore.Components.FluentDataGrid1.RefreshDataCoreAsync() in /_/src/Core/Components/DataGrid/FluentDataGrid.razor.cs:line 441 at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task) warn: Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer[100] Unhandled exception rendering component: Encountered unsupported frame type during diffing: None System.NotImplementedException: Encountered unsupported frame type during diffing: None at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForFramesWithSameSequence(DiffContext& diffContext, Int32 oldFrameIndex, Int32 newFrameIndex) at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl) at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException) at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue() fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111] Unhandled exception in circuit 'YuPjO_pwzTrlaOleTazA0R2U1tw6JTFjCokl3fsR85Q'. System.NotImplementedException: Encountered unsupported frame type during diffing: None at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForFramesWithSameSequence(DiffContext& diffContext, Int32 oldFrameIndex, Int32 newFrameIndex) at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl) at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException) at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()

Page is working in intertactiveserver mode

[vnbaaij]

To enable us to take a closer look, please create an issue and supply us with minimal working reproduction code we can run (project or repo).

[Doc415]

Alright thanks.

[Doc415]

I found that the Queryable i used for datagrid should not be queried in the code block to change the datagrid.
For example
MealsQuery=MealsQuery.Where(x=> x.Name.Contains("xxx"))
If the lambda expression can return null, the code always crashes even if there are null checking if statements.
I take out the querying to Service layer and update the MealsQuery with a method MealQuery=_Service.GetFilteredMeals().AsQueryable()
all problems were gone.