jQuery validation in ASP.NET MVC — jQuery

8. jQuery validation in ASP.NET MVC

Intermediate★ Must knowLesson 8 of 10

ASP.NET MVC tag helpers emit data-val-* attributes from data annotations; jQuery Validation + jQuery Unobtrusive Validation read them and validate on the client.

cshtml

@section Scripts {
    <partial name="_ValidationScriptsPartial" />   @* jquery.validate + jquery.validate.unobtrusive *@
}

// Re-parse validation after injecting a form via AJAX
const $form = $("#dynamicForm");
$form.removeData("validator").removeData("unobtrusiveValidation");
$.validator.unobtrusive.parse($form);

// Custom client rule paired with a server-side ValidationAttribute
$.validator.addMethod("notweekend", value => { const d = new Date(value).getDay(); return d !== 0 && d !== 6; });
$.validator.unobtrusive.adapters.addBool("notweekend");

if ($form.valid()) { /* submit via AJAX */ }

Server-side validation must still run — client validation is just for UX.