When called, shows a validation message using jQuery Validation. Can also optionally display the message in the validation summary.

showerror.js

(function ($) {
    $.showError = function(element, errorMessage, showInSummary, summaryLinkTargetElement) {
        var $element = $(element);
        var $form = $element.parents('form').first();
        var elementName = $element.attr('name');
        var elementLabel = $('label[for={0}]>span:first'.format(elementName)).text();
        var $validationSummary;
        var $validationLink;
        var $target = !summaryLinkTargetElement ? $element : $(summaryLinkTargetElement);
        
        var errors = {};
        errors[elementName] = errorMessage;
        $form.validate().showErrors(errors);

        if (showInSummary) {
            $form.find('.validation-summary-valid').removeClass('validation-summary-valid').addClass('validation-summary-errors');
            $validationSummary = $form.find('.validation-summary-errors');
            $validationSummary.find('ul').prepend(
                ('<li data-valmsg-for="{0}" style="">' + 
                '   <a role="button" href="#{0}" tabindex="0">{1}</a>' +
                '</li>').format(elementName, elementLabel));
            $validationLink = $('.validation-summary-errors a[href="#{0}"]'.format(elementName));
            $(window).scrollTop($validationSummary.offset().top);
            $validationLink.click(function(e) {
                e.preventDefault();
                $target.focus();
            });
        }
    };
}(jQuery));

Hi @jonathan

Can you explain this ??