TelerikRootComponent Overview

The TelerikRootComponent is a special component in Telerik UI for Blazor. Its placement and configuration affects all other Telerik Blazor components. This article describes the purpose and usage of TelerikRootComponent.

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Purpose

The TelerikRootComponent is responsible for the following tasks:

• It provides settings to all its child Telerik components, for example, for the icon type or right-to-left (RTL) support.
• It renders all Telerik popups, which has the following benefits:
  • It's more reliable that the popups will display on top of the other page content.
  • There is no risk for the popups to be trapped by scrollable containers, or clipped by containers with an overflow:hidden style.
• It exposes the DialogFactory for using predefined dialogs.

The TelerikRootComponent achieves all these tasks with the help of cascading values. That's why it is crucial for the root component to wrap all other Telerik components in the app, otherwise an exception may occur. To ensure correct popup position, it is also highly recommended for the TelerikRootComponent to be the top-level component in the app and wrap all other content, including the application layout.

Using TelerikRootComponent

This section applies to:

• .NET 8 and .NET 9 Blazor Web Apps with Global interactivity location. If your app has Per page/component interactivity, then refer to section Interactivity Considerations below.
• Blazor Server, WebAssembly and Hybrid apps in all .NET versions

The recommended way to add TelerikRootComponent to a Blazor app is to:

1. Create a new layout file in the app, for example, TelerikLayout.razor.
2. Place the new layout in the same folder as the default application layout MainLayout.razor.
3. Add a <TelerikRootComponent> tag to the new layout and set @Body as the root component's child content.
4. Make the new layout a parent of the default application layout.

Adding TelerikRootComponent to a new layout

@inherits LayoutComponentBase

<TelerikRootComponent>
    @Body
</TelerikRootComponent>

@inherits LayoutComponentBase
@layout TelerikLayout

@* The other MainLayout.razor content remains the same. *@

The above approach has the following benefits:

• There is a separation of concerns and a single TelerikRootComponent can be a parent of multiple other layouts.
• You can use DialogFactory (predefined Telerik dialogs) in MainLayout.razor.

However, you can also add <TelerikRootComponent> directly to an existing application layout, instead of creating a new one.

Adding TelerikRootComponent to MainLayout.razor

@inherits LayoutComponentBase

<TelerikRootComponent>
    @* All the MainLayout.razor content becomes nested in the Telerik root component. *@
</TelerikRootComponent>

Interactivity Considerations

.NET 8 introduced new render modes for Blazor web apps and the concept of static Blazor apps with optional interactive components. The following requirements and considerations apply to the TelerikRootComponent:

• The TelerikRootComponent must reside in an interactive layout or component.
• Application layouts are interactive only if the whole app is interactive. To achieve this, set Interactivity location of the app to Global during app creation.

If you are using Telerik components in a Blazor app with Per page/component interactivity location, then learn how to correctly add the TelerikRootComponent in this case.

TelerikRootComponent Parameters

Parameter	Type and Default Value	Description
EnableRtl	bool	Enables right-to-left (RTL) support.
IconType	IconType enum (Svg)	The icon type, which other Telerik components will use to render internal icons. Regardless of this parameter value, you can freely use the <TelerikFontIcon> and <TelerikSvgIcon> components, and set the Icon parameter of other Telerik components to any type that you wish.
Localizer	Telerik.Blazor.Services.ITelerikStringLocalizer	The Telerik localization service. The recommended approach is to define the localizer as a service in Program.cs. Use the Localizer parameter only in special cases when this is not possible.

See Also

• Popup Troubleshooting
• Setting up Telerik Blazor apps
• Exception: Telerik component requires a TelerikRootComponent