Last Updated: 15 Jan 2022 14:43 by ADMIN
Release 2.30.0
Marin Bratanov
Created on: 03 Jul 2020 10:34
Category: UI for Blazor
Type: Feature Request
Inputs to Validate only in the OnChange event, not on every keystroke

See more details in the following KB article: and if the behavior and solution there do not fit your needs, leave your comments and ideas on how you want this exposed for configuration and what the desired behavior is. Also, make sure to Vote for this enhancement so we can gauge the public interest in it.

Marin Bratanov
Posted on: 15 Jan 2022 14:43

Thank you for the kind words, Steve, we are happy when our customers are happy :)



Posted on: 12 Jan 2022 21:31

Telerik UI for Blazor 2.30 adds a ValidateOn parameter to input components. It defines the event that triggers validation (OnChange or OnInput). Read more at Validation Modes for Simple Inputs.


This is why your tools are amazing. You listen and respond to clients and provide a solution!


Thanks so much!


Posted on: 27 Oct 2021 17:49

Other components seem to allow this and don't have a problem.  Radzen's textbox allows this configuration.

We are also experiencing an issue when using the Telerik input components that the call to ValidateField and NotifyValidationStateChanged event handling takes longer on each call. Dropping in the default textbox or another one like Radzen's doesn't trigger this increase in processing time. It's a few milliseconds added to each call but if you have a form with several Telerik controls, it grows to seconds quickly.

Marin Bratanov
Posted on: 18 Mar 2021 19:31

Hello Scott,

That would be possible only on simple inputs that also don't need to handle other events internally. Unfortunately, for complex components like ours it won't be possible.


Marin Bratanov
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Posted on: 18 Mar 2021 18:23
I like that the default behavior is based on input, but there are sometimes when it does not make sense like email address input validation.

Would it be possible to support the bind event argument?

Posted on: 17 Dec 2020 14:32

Hi Marin


I don't have a suggestion, but I would appreciate if validation would just happen when the control looses the focus.

We have a few TextBoxes that it's configured with min/max length. 

I believe it looks strange when the user jumps into the text box and after putting in one char it shows already the error message.


Best Regards and Merry Xmas



Marin Bratanov
Posted on: 17 Dec 2020 09:10

Probably yes, Giuseppe, such a parameter is our current idea, but we use this page to gather other ideas and feedback too. So, if you have other suggestions, feel free to share them.


Marin Bratanov
Progress Telerik

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Posted on: 16 Dec 2020 12:44

Hi Marin


This vote is to have ValidateOnlyOnChange feature?




Posted on: 03 Jul 2020 16:33
It could be a nice feature to have it, especially as a parameter to switch it on or off because there might be valid cases for both scenarios.