Merge pull request #4501 from syncfusion-content/890741-UgDocSample

thavasianand · web-flow · commit 941888acf972 · 2024-06-18T16:06:24.000+05:30
890741: Ug Doc Sample
diff --git a/blazor/treegrid/getting-started-webapp.md b/blazor/treegrid/getting-started-webapp.md
@@ -294,6 +294,96 @@ The sorting feature enables to order the records. It can be enabled by setting t
 
 {% previewsample "https://blazorplayground.syncfusion.com/embed/rtLzNMKDzGDJVWCD?appbar=false&editor=false&result=true&errorlist=false&theme=bootstrap5" backgroundimage "[Blazor TreeGrid](images/blazor-treegrid.png)" %}
 
+## Handling exceptions
+
+Exception handling in Tree Grid identifies exceptions and notifies them through the [OnActionFailure](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.TreeGridEvents-1.html#Syncfusion_Blazor_TreeGrid_TreeGridEvents_1_OnActionFailure) event. When configuring the Tree Grid or enabling specific features through its API, mistakes can occur. The `OnActionFailure` event can be used to manage these exceptions. This event triggers when such mistakes happen. The `OnActionFailure` event handles various scenarios, including:
+
+* For CRUD operations, row drag and drop, and persisiting the selection, ensure the [IsPrimaryKey](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.TreeGridColumn.html#Syncfusion_Blazor_TreeGrid_TreeGridColumn_IsPrimaryKey) property is mapped to a unique data column. Failure to do so will cause an exception.
+* [Paging](https://blazor.syncfusion.com/documentation/treegrid/paging) is not supported with [Virtualization](https://blazor.syncfusion.com/documentation/treegrid/virtualization). Enabling `Paging` with `Virtualization` will result in an exception.
+* To render the Tree Grid, map either the [DataSource](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.SfTreeGrid-1.html#Syncfusion_Blazor_TreeGrid_SfTreeGrid_1_DataSource) or [Columns](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.SfTreeGrid-1.html#Syncfusion_Blazor_TreeGrid_SfTreeGrid_1_Columns) property. Failure to do so will result in an exception.
+* Freeze columns by mapping either [IsFrozen](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.TreeGridColumn.html#Syncfusion_Blazor_TreeGrid_SfTreeGrid_1_IsFrozen) or [FrozenColumns](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.SfTreeGrid-1.html#Syncfusion_Blazor_TreeGrid_SfTreeGrid_1_FrozenColumns). Enabling both properties simultaneously will result in an exception.
+* The [DetailTemplate](https://blazor.syncfusion.com/documentation/treegrid/rows/detail-template) is not supported with `Virtualization` and `Stacked Header`. Enabling them with these features will result in an exception.
+
+* The [FrozenRows](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.SfTreeGrid-1.html#Syncfusion_Blazor_TreeGrid_SfTreeGrid_1_FrozenRows) and `FrozenColumns` are not supported with [RowTemplate](https://blazor.syncfusion.com/documentation/treegrid/rows/row-template), `DetailTemplate`, and [Cell Editing](https://blazor.syncfusion.com/documentation/treegrid/editing/cell-editing). Enabling them with these features will result in an exception.
+
+* In `Stacked Header`, the [Freeze](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.TreeGridColumn.html#Syncfusion_Blazor_TreeGrid_TreeGridColumn_Freeze) direction is incompatible with [Column Reordering](https://blazor.syncfusion.com/documentation/treegrid/columns/column-reorder).  
+* [Selection](https://blazor.syncfusion.com/documentation/treegrid/selection) functionality is not supported when using `RowTemplate`. Enabling both properties simultaneously will result in an exception.
+* Set the [TreeColumnIndex](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.SfTreeGrid-1.html#Syncfusion_Blazor_TreeGrid_SfTreeGrid_1_TreeColumnIndex) value to display the tree structure. Make sure the value does not exceed the total column count, or it will result in an exception.
+* For `Virtualization`, do not specify height and width in percentages. Using percentages will result in an error.
+* When using the default filter ([FilterBar](https://blazor.syncfusion.com/documentation/treegrid/filtering/filter-bar)) type, do not apply the other [FilterType](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.FilterType.html) to columns within the same tree grid, as this will result in an exception.
+* In Tree Grid, avoid enabling [IdMapping](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.SfTreeGrid-1.html#Syncfusion_Blazor_TreeGrid_SfTreeGrid_1_IdMapping) and [ChildMapping](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.SfTreeGrid-1.html#Syncfusion_Blazor_TreeGrid_SfTreeGrid_1_ChildMapping) simultaneously. Enabling both properties at the same time will result in an exception.
+* The [ShowCheckbox](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.TreeGridColumn.html#Syncfusion_Blazor_TreeGrid_TreeGridColumn_ShowCheckbox) column should only be defined in the tree column. Defining it elsewhere will result in an exception.
+* The [TextAlign](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.TreeGridColumn.html#Syncfusion_Blazor_TreeGrid_TreeGridColumn_TextAlign) right is not applicable for tree columns in the Tree Grid.  Enabling right alignment for tree columns will result in an exception.
+
+The following code example shows how to use the [OnActionFailure](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.TreeGrid.TreeGridEvents-1.html#Syncfusion_Blazor_TreeGrid_TreeGridEvents_1_OnActionFailure) event in the Tree Grid control to display an exception when `IsPrimaryKey`are not configured properly in the Tree Grid.
+
+{% tabs %}
+{% highlight razor %}
+
+@using Syncfusion.Blazor.TreeGrid;
+@using Syncfusion.Blazor.Data;
+
+ <span class="error">@ErrorDetails</span>
+<SfTreeGrid DataSource="@TreeData" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="1">
+    <TreeGridEditSettings AllowEditing></TreeGridEditSettings>
+    <TreeGridEvents TValue="BusinessObject" OnActionFailure="ActionFailure"></TreeGridEvents>
+    <TreeGridColumns>
+        <TreeGridColumn Field="TaskId" HeaderText="Task ID" Width="80" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
+        <TreeGridColumn Field="TaskName" HeaderText="Task Name" Width="160"></TreeGridColumn>
+        <TreeGridColumn Field="StartDate" HeaderText="Start Date" Format="d" Type="Syncfusion.Blazor.Grids.ColumnType.DateOnly" Width="152" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
+        <TreeGridColumn Field="StartTime" HeaderText="Start Time" Type="Syncfusion.Blazor.Grids.ColumnType.TimeOnly" Width="100" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
+        <TreeGridColumn Field="Duration" HeaderText="Duration" Width="100" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
+        <TreeGridColumn Field="Progress" HeaderText="Progress" Width="100" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
+    </TreeGridColumns>
+</SfTreeGrid>
+<style>
+    .error {
+        color: red;
+    }
+</style>
+
+@code{
+
+    private string ErrorDetails = "";
+    public class BusinessObject
+    {
+        public int TaskId { get; set; }
+        public string TaskName { get; set; }
+        public DateOnly? StartDate { get; set; }
+        public TimeOnly? StartTime { get; set; }
+        public int Duration { get; set; }
+        public int Progress { get; set; }
+        public string Priority { get; set; }
+        public int? ParentId { get; set; }
+    }
+
+    public void ActionFailure(Syncfusion.Blazor.Grids.FailureEventArgs args)
+    {
+        this.ErrorDetails = args.Error.Message.ToString();
+        StateHasChanged();
+    }
+
+    public List<BusinessObject> TreeData = new List<BusinessObject>();
+
+    protected override void OnInitialized()
+    {
+        TreeData.Add(new BusinessObject() { TaskId = 1, TaskName = "Parent Task 1", StartDate = new DateOnly(2021, 03, 02), StartTime = new TimeOnly(10, 00, 00), Duration = 10, Progress = 70, ParentId = null, Priority = "High" });
+        TreeData.Add(new BusinessObject() { TaskId = 2, TaskName = "Child task 1", StartDate = new DateOnly(2021, 03, 04), StartTime = new TimeOnly(11, 30, 00), Duration = 4, Progress = 80, ParentId = 1, Priority = "Normal" });
+        TreeData.Add(new BusinessObject() { TaskId = 3, TaskName = "Child Task 2", StartDate = new DateOnly(2021, 03, 06), StartTime = new TimeOnly(12, 00, 00), Duration = 5, Progress = 65, ParentId = 1, Priority = "Critical" });
+        TreeData.Add(new BusinessObject() { TaskId = 4, TaskName = "Parent Task 2", StartDate = new DateOnly(2021, 03, 08), StartTime = new TimeOnly(13, 30, 00), Duration = 6, Progress = 77, ParentId = null, Priority = "Low" });
+        TreeData.Add(new BusinessObject() { TaskId = 5, TaskName = "Child Task 5", StartDate = new DateOnly(2021, 07, 10), StartTime = new TimeOnly(14, 00, 00), Duration = 9, Progress = 25, ParentId = 4, Priority = "Normal" });
+        TreeData.Add(new BusinessObject() { TaskId = 6, TaskName = "Child Task 6", StartDate = new DateOnly(2021, 10, 12), StartTime = new TimeOnly(16, 00, 00), Duration = 9, Progress = 7, ParentId = 5, Priority = "Normal" });
+        TreeData.Add(new BusinessObject() { TaskId = 7, TaskName = "Parent Task 3", StartDate = new DateOnly(2021, 10, 14), StartTime = new TimeOnly(17, 30, 00), Duration = 4, Progress = 45, ParentId = null, Priority = "High" });
+        TreeData.Add(new BusinessObject() { TaskId = 8, TaskName = "Child Task 7", StartDate = new DateOnly(2021, 10, 16), StartTime = new TimeOnly(18, 00, 00), Duration = 3, Progress = 38, ParentId = 7, Priority = "Critical" });
+        TreeData.Add(new BusinessObject() { TaskId = 9, TaskName = "Child Task 8", StartDate = new DateOnly(2021, 02, 18), StartTime = new TimeOnly(19, 30, 00), Duration = 7, Progress = 70, ParentId = 7, Priority = "Low" });
+    }
+}
+
+{% endhighlight %}
+{% endtabs %}
+
+{% previewsample "https://blazorplayground.syncfusion.com/embed/hNVztHsLJVPJfMvO?appbar=false&editor=false&result=true&errorlist=false&theme=bootstrap5" %}
+
 ## See also
 
 * [Getting Started with Syncfusion Blazor for Server-Side in .NET Core CLI](https://blazor.syncfusion.com/documentation/getting-started/blazor-server-side-dotnet-cli)
