890806: Added documentation for exception handling

ej2-asp-core-mvc/code-snippet/tree-grid/getting-start-core/error-handling/errorHandling.cs

@@ -0,0 +1,6 @@
+public IActionResult Index()
+{
+    var tree = TreeData.GetDefaultData();
+    ViewBag.dataSource = tree;
+    return View();
+}

ej2-asp-core-mvc/code-snippet/tree-grid/getting-start-core/error-handling/tagHelper

@@ -0,0 +1,17 @@
+<ejs-treegrid id="TreeGrid" dataSource="@ViewBag.dataSource" height="400" childMapping="Children" treeColumnIndex="1" actionFailure="actionFailure" >
+    <e-treegrid-editsettings allowAdding="true" allowEditing="true" allowDeleting="true"></e-treegrid-editsettings>
+    <e-treegrid-columns>
+        <e-treegrid-column field="TaskId" headerText="Task ID" textAlign="Right" width="100"></e-treegrid-column>
+        <e-treegrid-column field="TaskName" headerText="Task Name" editType="stringedit" width="190"></e-treegrid-column>
+        <e-treegrid-column field="StartDate" headerText="Start Date" editType="datepickeredit" textAlign="Right" format="yMd" type="date" width="130"></e-treegrid-column>
+        <e-treegrid-column field="Duration" headerText="Duration" editType="numericedit" textAlign="Right" width="120"></e-treegrid-column>
+    </e-treegrid-columns>
+</ejs-treegrid>
+<script>
+    function actionFailure(e) {
+       var span = document.createElement('span');
+       this.element.parentNode.insertBefore(span, this.element);
+       span.style.color = '#FF0000'
+       span.innerHTML = e.error[0];
+    }
+</script>

ej2-asp-core-mvc/code-snippet/tree-grid/getting-start-mvc/error-handling/errorHandling.cs

@@ -0,0 +1,93 @@
+public class HomeController : Controller
+{
+    public ActionResult Index()
+    {
+        return View(TreeGridItems.GetTreeData());
+    }
+}
+public class TreeGridItems
+{
+    public TreeGridItems() { }
+    public int TaskId { get; set; }
+    public string TaskName { get; set; }
+    public DateTime StartDate { get; set; }
+    public int Duration { get; set; }
+    public List<TreeGridItems> Children { get; set; }
+
+    public static List<TreeGridItems> GetTreeData()
+    {
+        List<TreeGridItems> BusinessObjectCollection = new List<TreeGridItems>();
+
+        TreeGridItems Record1 = null;
+
+        Record1 = new TreeGridItems()
+        {
+            TaskId = 1,
+            TaskName = "Planning",
+            StartDate = new DateTime(2016, 06, 07),
+            Duration = 5,
+            Children = new List<TreeGridItems>(),
+        };
+        TreeGridItems Child1 = new TreeGridItems()
+        {
+            TaskId = 2,
+            TaskName = "Plan timeline",
+            StartDate = new DateTime(2016, 06, 07),
+            Duration = 5
+        };
+
+        TreeGridItems Child2 = new TreeGridItems()
+        {
+            TaskId = 3,
+            TaskName = "Plan budget",
+            StartDate = new DateTime(2016, 06, 07),
+            Duration = 5
+        };
+        TreeGridItems Child3 = new TreeGridItems()
+        {
+            TaskId = 4,
+            TaskName = "Allocate resources",
+            StartDate = new DateTime(2016, 06, 07),
+            Duration = 5
+        };
+        Record1.Children.Add(Child1);
+        Record1.Children.Add(Child2);
+        Record1.Children.Add(Child3);
+        TreeGridItems Record2 = new TreeGridItems()
+        {
+            TaskId = 6,
+            TaskName = "Design",
+            StartDate = new DateTime(2021, 08, 25),
+            Duration = 3,
+            Children = new List<TreeGridItems>()
+        };
+        TreeGridItems Child5 = new TreeGridItems()
+        {
+            TaskId = 7,
+            TaskName = "Software Specification",
+            StartDate = new DateTime(2021, 08, 25),
+            Duration = 3
+        };
+
+        TreeGridItems Child6 = new TreeGridItems()
+        {
+            TaskId = 8,
+            TaskName = "Develop prototype",
+            StartDate = new DateTime(2021, 08, 25),
+            Duration = 3
+        };
+        TreeGridItems Child7 = new TreeGridItems()
+        {
+            TaskId = 9,
+            TaskName = "Get approval from customer",
+            StartDate = new DateTime(2024, 06, 27),
+            Duration = 2
+        };
+        Record2.Children.Add(Child5);
+        Record2.Children.Add(Child6);
+        Record2.Children.Add(Child7);
+        BusinessObjectCollection.Add(Record1);
+        BusinessObjectCollection.Add(Record2);
+        return BusinessObjectCollection;
+    }
+}

ej2-asp-core-mvc/code-snippet/tree-grid/getting-start-mvc/error-handling/razor

@@ -0,0 +1,31 @@
+@using Syncfusion.EJ2.Grids
+@model List<TreeGridSample.Controllers.TreeGridItems>
+
+@(Html.EJS().TreeGrid("TreeGrid").DataSource((IEnumerable<object>)ViewBag.datasource)
+      .EditSettings(edit =>
+       {
+          edit.AllowAdding(true);
+          edit.AllowDeleting(true);
+          edit.AllowEditing(true);
+       })
+       .Columns(col =>
+        {
+           col.Field("TaskId").HeaderText("Task ID").Width(120)
+              .TextAlign(TextAlign.Right).Add();
+           col.Field("TaskName").HeaderText("Task Name").Add();
+           col.Field("StartDate").HeaderText("Start Date").Width(150).Format("yMd")
+              .EditType("datepickeredit").TextAlign(TextAlign.Right).Add();
+           col.Field("Duration").HeaderText("Duration").Width("110").EditType("numericedit")
+               .Edit(new { @params = new { format = "n" } }).TextAlign(TextAlign.Right).Add();
+
+        }).Height(400).ChildMapping("Children").ActionFailure("actionFailure").TreeColumnIndex(1).Render())
+
+         < script >
+            function actionFailure(args) {
+               var treegrid = document.getElementById("TreeGrid").ej2_instances[0];
+               var span = document.createElement('span');
+               treegrid.element.parentNode.insertBefore(span, treegrid.element);
+               span.style.color = '#FF0000'
+               span.innerHTML = args.error[0];
+            }
+         </ script >

ej2-asp-core-mvc/tree-grid/EJ2_ASP.MVC/getting-started-mvc.md

@@ -188,6 +188,38 @@ By default, filtered records are shown along with its parent records. This behav
 
 ![ASP.NET MVC Tree Grid with Filtering](images/treegrid-sample.png)
 
+## Handling errors
+
+Error handling in Tree Grid identifies exceptions and notifies them through the [actionFailure](https://help.syncfusion.com/cr/aspnetmvc-js2/syncfusion.ej2.treegrid.treegrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_ActionFailure) event. When configuring the Tree Grid or enabling specific features through its API, mistakes can occur. The `actionFailure` event can be used to manage these errors. This event triggers when such mistakes happen. The `actionFailure` event handles various scenarios, including:
+
+* For CRUD operations, row drag and drop, and persisiting the selection, ensure the `isPrimaryKey` property is mapped to a unique data column. Failure to do so will cause an error.
+* [Paging](https://ej2.syncfusion.com/aspnetmvc/documentation/tree-grid/paging) is not supported with [virtualization](https://ej2.syncfusion.com/aspnetmvc/documentation/tree-grid/virtual-scroll). Enabling `paging` with `virtualization` will result in an error.
+* To render the Tree Grid, map either the [dataSource](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_DataSource) or [columns](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_Columns) property. Failure to do so will result in an error.
+* Freeze columns by mapping either `isFrozen` or [frozenColumns](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_FrozenColumns). Enabling both properties simultaneously will result in an error.
+* The [detailTemplate](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_DetailTemplate) is not supported with `virtualization` and `stacked header`. Enabling them with these features will result in an error.
+* The [frozenRows](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_FrozenRows) and `frozenColumns` are not supported with [rowTemplate](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_RowTemplate), `detailTemplate`, and [cell editing](https://ej2.syncfusion.com/aspnetmvc/documentation/tree-grid/editing/cell-editing). Enabling them with these features will result in an error.
+* In `stacked header`, the `freeze` direction is incompatible with [column reordering](https://ej2.syncfusion.com/aspnetmvc/documentation/tree-grid/columns/column-reorder).
+* [Selection](https://ej2.syncfusion.com/aspnetmvc/documentation/tree-grid/selection/selection) functionality is not supported when using `rowTemplate`. Enabling both properties simultaneously will result in an error.
+* Set the [treeColumnIndex](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_TreeColumnIndex) value to display the tree structure. Make sure the value does not exceed the total column count, or it will result in an error.
+* For `virtualization`, do not specify height and width in percentages. Using percentages will result in an error.
+* When using the default filter ([filterbar](https://ej2.syncfusion.com/aspnetmvc/documentation/tree-grid/filtering/filter-bar)) type, do not apply the other [filterType](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.FilterType.html) to any column in the same tree grid, as this will cause an error.
+* In Tree Grid, avoid enabling [idMapping](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_IdMapping) and [childMapping](https://help.syncfusion.com/cr/aspnetmvc-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_ChildMapping) simultaneously. Enabling both properties at the same time will result in an error.
+* The `showCheckbox` column should only be defined in the tree column. Defining it elsewhere will result in an error.
+* The `textAlign` right is not applicable for tree columns in the Tree Grid. Enabling right alignment for tree columns will result in an error.
+
+The following code example shows how to use the [actionFailure](https://help.syncfusion.com/cr/aspnetmvc-js2/syncfusion.ej2.treegrid.treegrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_ActionFailure) event in the Tree Grid control to display an exception when `isPrimaryKey` are not configured properly in the Tree Grid.
+
+{% tabs %}
+{% highlight razor tabtitle="CSHTML" %}
+{% include code-snippet/tree-grid/getting-start-mvc/error-handling/razor %}
+{% endhighlight %}
+{% highlight c# tabtitle="HomeController.cs" %}
+{% include code-snippet/tree-grid/getting-start-mvc/error-handling/errorHandling.cs %}
+{% endhighlight %}
+{% endtabs %}
+
+![ASP.NET MVC Tree Grid with Handling errors](images/error-handling.png)
+
 N> [View Sample in GitHub](https://github.com/SyncfusionExamples/ASP-NET-MVC-Getting-Started-Examples/tree/main/TreeGrid/ASP.NET%20MVC%20Razor%20Examples).
 
 N> You can refer to our [ASP.NET MVC Tree Grid](https://www.syncfusion.com/aspnet-mvc-ui-controls/tree-grid) feature tour page for its groundbreaking feature representations. You can also explore our [ASP.NET MVC Tree Grid example](https://ej2.syncfusion.com/aspnetmvc/TreeGrid/Overview#/material) to knows how to present and manipulate data.

ej2-asp-core-mvc/tree-grid/EJ2_ASP.NETCORE/getting-started-core.md

@@ -612,6 +612,38 @@ public class TreeGridItems
 
 N> [View Sample in GitHub](https://github.com/SyncfusionExamples/ASP-NET-Core-Getting-Started-Examples/tree/main/TreeGrid/ASP.NET%20Core%20Tag%20Helper%20Examples).
 
+## Handling errors
+
+Error handling in Tree Grid identifies exceptions and notifies them through the [actionFailure](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_ActionFailure) event. When configuring the Tree Grid or enabling specific features through its API, mistakes can occur. The `actionFailure` event can be used to manage these errors. This event triggers when such mistakes happen. The `actionFailure` event handles various scenarios, including:
+
+* For CRUD operations, row drag and drop, and persisiting the selection, ensure the `isPrimaryKey` property is mapped to a unique data column. Failure to do so will cause an error.
+* [Paging](https://ej2.syncfusion.com/aspnetcore/documentation/tree-grid/paging) is not supported with [virtualization](https://ej2.syncfusion.com/aspnetcore/documentation/tree-grid/virtual-scroll). Enabling `paging` with `virtualization` will result in an error.
+* To render the Tree Grid, map either the [dataSource](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_DataSource) or [columns](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_Columns) property. Failure to do so will result in an error.
+* Freeze columns by mapping either `isFrozen` or [frozenColumns](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_FrozenColumns). Enabling both properties simultaneously will result in an error.
+* The [detailTemplate](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_DetailTemplate) is not supported with `virtualization` and `stacked header`. Enabling them with these features will result in an error.
+* The [frozenRows](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_FrozenRows) and `frozenColumns` are not supported with [rowTemplate](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_RowTemplate), `detailTemplate`, and [cell editing](https://ej2.syncfusion.com/aspnetcore/documentation/tree-grid/editing/cell-editing). Enabling them with these features will result in an error.
+* In `stacked header`, the `freeze` direction is incompatible with [column reordering](https://ej2.syncfusion.com/aspnetcore/documentation/tree-grid/columns/column-reorder).
+* [Selection](https://ej2.syncfusion.com/aspnetcore/documentation/tree-grid/selection/selection) functionality is not supported when using `rowTemplate`. Enabling both properties simultaneously will result in an error.
+* Set the [treeColumnIndex](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_TreeColumnIndex) value to display the tree structure.  Make sure the value does not exceed the total column count, or it will result in an error.
+* For `virtualization`, do not specify height and width in percentages. Using percentages will result in an error.
+* When using the default filter ([filterbar](https://ej2.syncfusion.com/aspnetcore/documentation/tree-grid/filtering/filter-bar)) type, do not apply the other [filterType](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.FilterType.html) to columns within the same tree grid, as this will result in an error.
+* In Tree Grid avoid enabling [idMapping](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_IdMapping) and [childMapping](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_ChildMapping) simultaneously. Enabling both properties at the same time will result in an error.
+* The `showCheckbox` column should only be defined in the tree column. Defining it elsewhere will result in an error.
+* The `textAlign` right is not applicable for tree columns in the Tree Grid. Enabling right alignment for tree columns will result in an error.
+
+The following code example shows how to use the [actionFailure](https://help.syncfusion.com/cr/aspnetcore-js2/Syncfusion.EJ2.TreeGrid.TreeGrid.html#Syncfusion_EJ2_TreeGrid_TreeGrid_ActionFailure) event in the Tree Grid control to display an exception when `isPrimaryKey` are not configured properly in the Tree Grid.
+
+{% tabs %}
+{% highlight cshtml tabtitle="CSHTML" %}
+{% include code-snippet/tree-grid/getting-start-core/error-handling/tagHelper %}
+{% endhighlight %}
+{% highlight c# tabtitle="ErrorHandling.cs" %}
+{% include code-snippet/tree-grid/getting-start-mvc/error-handling/errorHandling.cs %}
+{% endhighlight %}
+{% endtabs %}
+
+![ASP.NET CORE Tree Grid with Handling errors](images/error-handling.png)
+
 ## See also
 
 * [Getting Started with Syncfusion ASP.NET Core using Razor Pages](https://ej2.syncfusion.com/aspnetcore/documentation/getting-started/razor-pages/)