Blazor Validation Tools Overview

Telerik UI for Blazor provides different ways to show and customize validation messages. The validation tools can be used together with the Telerik Form or with any form that provides an EditContext like the standard Blazor EditForm.

The Telerik Blazor validation tools let you match the style of your validation messages to all other Telerik Blazor components in your app. The validation tools do not expose API or settings for specific validation logic. You need to handle the validation logic separately and then use the Telerik Blazor UI components to display messages to the end user.

Validation Tools

Telerik UI for Blazor provides the following validation tools to help you style your form validation:

• Validation Summary
• Validation Message
• Validation Tooltip

These components add default styling and customization options on top of the standard Blazor validation tools ValidationSummary and ValidationMessage.

The validation components must receive an EditContext instance as a cascading parameter, so they can reside in a Telerik Form or a standard Blazor EditForm.

When using the Form EditContext parameter together with validation components or Form item <Template>s, make sure to create the EditContext from the model instance, which is used by the validation components and inside the Form item templates. Otherwise, the Form will not update the correct object instance and validation will not work as expected.

The Telerik components for Blazor do not perform the actual validation of the model. Validation is managed by the EditContext. The role of the Telerik components is to call EditContext methods, subscribe to EditContext events, retrieve validation messages, and display them. If a validation scenario does not work as expected, check the behavior in a standard Blazor <EditForm> to verify if the issue is related to the Telerik components.

Next Steps

• Use TelerikValidationSummary
• Explore TelerikValidationMessage
• Try TelerikValidationTooltip

See Also

• Live Demo: Validation
• Form Component