Add GridCommandColumn HeaderTemplate documentation (#3296)

* Initial plan

* Add GridCommandColumn HeaderTemplate documentation

Co-authored-by: xristianstefanov <[email protected]>

* chore(Grid): polish docs

* chore(Grid): add proper meta field

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: xristianstefanov <[email protected]>
Co-authored-by: Hristian Stefanov <[email protected]>

Author: Copilot

components/grid/columns/command.md

@@ -21,6 +21,7 @@ In this article:
    * [Built-in Commands](#built-in-commands)
    * [OnClick Handler](#the-onclick-handler)
    * [Context](#context)
+   * [Header Template](#header-template)
 * [Code Example](#example)
 
 ## Features
@@ -91,6 +92,10 @@ Use a **named** context variable to avoid errors when nesting components or `Ren
 </GridCommandColumn>
 ````
 
+### Header Template
+
+The Grid command column supports [`HeaderTemplate`](slug:grid-templates-command-column-header) that allows you to customize the header cell's rendering.
+
 ## Example
 
 The following code example demonstrates declarations and handling.

components/grid/templates/column-header.md

@@ -88,7 +88,7 @@ Bound columns render the name of the field or their `Title` in their header. Thr
 
 ![Blazor Grid Header Template](images/header-template.png)
 
->note Header Templates are not available for the `GridCheckboxColumn` and the `GridCommandColumn`.
+>note Header Templates are not available for the `GridCheckboxColumn`.
 
 ## See Also
 

components/grid/templates/command-column-header.md

@@ -0,0 +1,78 @@
+---
+title: Command Column Header
+meta_title: Grid - Command Column Header Template
+description: Use custom command column header template in Grid for Blazor.
+slug: grid-templates-command-column-header
+tags: telerik,blazor,grid,templates,command,column,header
+published: True
+position: 23
+---
+
+# Command Column Header Template
+
+The `HeaderTemplate` of the Grid command column enables you to customize the header cell's rendering and add custom content or components in the command column header.
+
+>caption Grid Command Column Header Template
+
+````RAZOR
+@* Customize the header of the command column *@
+
+<TelerikGrid Data="@GridData"
+             EditMode="@GridEditMode.Inline"
+             OnUpdate="@OnUpdateHandler"
+             Pageable="true"
+             Height="400px">
+    <GridColumns>
+        <GridColumn Field="@nameof(Product.Name)" Title="Product Name" />
+        <GridColumn Field="@nameof(Product.Price)" Title="Price" />
+        <GridColumn Field="@nameof(Product.Quantity)" Title="Quantity" />
+        <GridCommandColumn Width="280px">
+            <HeaderTemplate>
+                <TelerikSvgIcon Icon="@SvgIcon.Gear" />
+                <strong>Actions</strong>
+            </HeaderTemplate>
+            <GridCommandButton Command="Edit" Icon="@SvgIcon.Pencil">Edit</GridCommandButton>
+            <GridCommandButton Command="Save" Icon="@SvgIcon.Save" ShowInEdit="true">Update</GridCommandButton>
+            <GridCommandButton Command="Cancel" Icon="@SvgIcon.Cancel" ShowInEdit="true">Cancel</GridCommandButton>
+            <GridCommandButton Command="Delete" Icon="@SvgIcon.Trash">Delete</GridCommandButton>
+        </GridCommandColumn>
+    </GridColumns>
+</TelerikGrid>
+
+@code {
+    private List<Product> GridData { get; set; } = new List<Product>();
+
+    private async Task OnUpdateHandler(GridCommandEventArgs args)
+    {
+        var updatedItem = args.Item as Product;
+        var index = GridData.FindIndex(p => p.Id == updatedItem.Id);
+        if (index != -1)
+        {
+            GridData[index] = updatedItem;
+        }
+    }
+
+    protected override void OnInitialized()
+    {
+        GridData = Enumerable.Range(1, 10).Select(x => new Product
+        {
+            Id = x,
+            Name = "Product " + x,
+            Price = Random.Shared.Next(1, 100),
+            Quantity = Random.Shared.Next(0, 50)
+        }).ToList();
+    }
+
+    public class Product
+    {
+        public int Id { get; set; }
+        public string Name { get; set; }
+        public decimal Price { get; set; }
+        public int Quantity { get; set; }
+    }
+}
+````
+
+## See Also
+
+* [Grid Command Column](slug:components/grid/columns/command)