[DataGrid] Make SelectColumn respond to programmatic changes in grid data

examples/Demo/Shared/Microsoft.FluentUI.AspNetCore.Components.xml

@@ -1842,6 +1842,9 @@
         <member name="M:Microsoft.FluentUI.AspNetCore.Components.SelectColumn`1.OnKeyAllAsync(Microsoft.AspNetCore.Components.Web.KeyboardEventArgs)">
             <summary />
         </member>
+        <member name="M:Microsoft.FluentUI.AspNetCore.Components.SelectColumn`1.Dispose">
+            <inheritdoc />
+        </member>
         <member name="T:Microsoft.FluentUI.AspNetCore.Components.SortedProperty">
             <summary>
             Holds the name of a property and the direction to sort by.

src/Core/Components/DataGrid/Columns/SelectColumn.cs

@@ -5,14 +5,15 @@
 using Microsoft.AspNetCore.Components;
 using Microsoft.AspNetCore.Components.Rendering;
 using Microsoft.AspNetCore.Components.Web;
+using Microsoft.FluentUI.AspNetCore.Components.Infrastructure;
 
 namespace Microsoft.FluentUI.AspNetCore.Components;
 
 /// <summary>
 /// Represents a <see cref="FluentDataGrid{TGridItem}"/> column whose cells render a selected checkbox updated when the user click on a row.
 /// </summary>
 /// <typeparam name="TGridItem">The type of data represented by each row in the grid.</typeparam>
-public class SelectColumn<TGridItem> : ColumnBase<TGridItem>
+public class SelectColumn<TGridItem> : ColumnBase<TGridItem>, IDisposable
 {
     /// <summary>
     /// List of keys to press, to select/unselect a row.
@@ -27,13 +28,23 @@ public class SelectColumn<TGridItem> : ColumnBase<TGridItem>
     private DataGridSelectMode _selectMode = DataGridSelectMode.Single;
     private readonly List<TGridItem> _selectedItems = [];
 
+    private readonly EventCallbackSubscriber<object?> _itemsChanged;
+
     /// <summary>
     /// Initializes a new instance of <see cref="SelectColumn{TGridItem}"/>.
     /// </summary>
     public SelectColumn()
     {
         Width = "50px";
         ChildContent = GetDefaultChildContent();
+
+        _itemsChanged = new(EventCallback.Factory.Create<object?>(this, UpdateSelectedItemsAsync));
+    }
+
+    protected override void OnInitialized()
+    {
+        _itemsChanged.SubscribeOrMove(InternalGridContext.ItemsChanged);
+        base.OnInitialized();
     }
 
     /// <summary>
@@ -326,6 +337,21 @@ Task CallOnSelectAsync(TGridItem item, bool isSelected)
         }
     }
 
+    private async Task UpdateSelectedItemsAsync()
+    {
+
+        if (!SelectedItems.Any() || InternalGridContext == null || InternalGridContext.Items == null)
+        {
+            return;
+        }
+
+        var itemsToRemove = _selectedItems.Where(item => !InternalGridContext.Items.Contains(item)).ToList();
+        foreach (var item in itemsToRemove)
+        {
+            await AddOrRemoveSelectedItemAsync(item);
+        }
+    }
+
     private Icon GetIcon(bool? selected)
     {
         if (selected == true)
@@ -555,6 +581,13 @@ internal async Task OnKeyAllAsync(KeyboardEventArgs e)
             await OnClickAllAsync(new MouseEventArgs());
         }
     }
+
+    /// <inheritdoc />
+    public void Dispose()
+    {
+        _itemsChanged.Dispose();
+
+    }
 }
 
 public record SelectAllTemplateArgs(bool? AllSelected) { }

src/Core/Components/DataGrid/FluentDataGrid.razor.cs

@@ -789,6 +789,8 @@ private async Task RefreshDataCoreAsync()
         if (!thisLoadCts.IsCancellationRequested)
         {
             _internalGridContext.Items = result.Items;
+            await _internalGridContext.ItemsChanged.InvokeCallbacksAsync(null);
+
             _internalGridContext.TotalItemCount = result.TotalItemCount;
             if (RefreshItems is null)
             {
@@ -831,7 +833,7 @@ private async Task RefreshDataCoreAsync()
 
         if (!request.CancellationToken.IsCancellationRequested)
         {
-            // ARIA's rowcount is part of the UI, so it should reflect what the human user regards as the number of rows in the table,
+            // ARIA's row count is part of the UI, so it should reflect what the human user regards as the number of rows in the table,
             // not the number of physical <tr> elements. For virtualization this means what's in the entire scrollable range, not just
             // the current viewport. In the case where you're also paginating then it means what's conceptually on the current page.
             // TODO: This currently assumes we always want to expand the last page to have ItemsPerPage rows, but the experience might

src/Core/Components/DataGrid/Infrastructure/InternalGridContext.cs

@@ -1,10 +1,14 @@
+// ------------------------------------------------------------------------
+// This file is licensed to you under the MIT License.
+// ------------------------------------------------------------------------
+
 using Microsoft.FluentUI.AspNetCore.Components.Infrastructure;
 
 namespace Microsoft.FluentUI.AspNetCore.Components.DataGrid.Infrastructure;
 
 // The grid cascades this so that descendant columns can talk back to it. It's an internal type
 // so that it doesn't show up by mistake in unrelated components.
-internal sealed class InternalGridContext<TGridItem>
+internal sealed class InternalGridContext<TGridItem>(FluentDataGrid<TGridItem> grid)
 {
     private int _index = 0;
     private int _rowId = 0;
@@ -19,13 +23,9 @@ internal sealed class InternalGridContext<TGridItem>
     public int TotalItemCount { get; set; }
     public int TotalViewItemCount { get; set; }
 
-    public FluentDataGrid<TGridItem> Grid { get; }
+    public FluentDataGrid<TGridItem> Grid { get; } = grid;
     public EventCallbackSubscribable<object?> ColumnsFirstCollected { get; } = new();
-
-    public InternalGridContext(FluentDataGrid<TGridItem> grid)
-    {
-        Grid = grid;
-    }
+    public EventCallbackSubscribable<object?> ItemsChanged { get; } = new();
 
     public int GetNextRowId()
     {