Hello everyone,

I want to check the uniqueness of a username field in a popup edit screen. I feel like a custom validation rule is the way to go but I can not figure out how to accomplish this. It appears that JQuery is deprecating the async = false setting in 1.8 so I do not think this is a valid option. 

Any Suggestions?

Hello Oliver,

If I understood correctly you would like to perform a remote validation. I am afraid that currently the Kendo validator does not support such functionality, however we will appreciate if you submit this as a feature request in the user voice forum. Thus way we would be able to monitor the interest in the idea and if it turns out to be popular we will consider its implementation in one of the future versions.

Currently the only possible way is by async: false Ajax requests. Kendo depends on jQuery v.1.7.1 so you may consider using this version (where the option is not deprecated) instead of 1.8. In case you are wondering how to create a custom Kendo validation rule, please check the corresponding component documentation as well as the validator overview article.

Kind regards,
Alexander Valchev
the Telerik team