Validity is a powerful and flexible jQuery form validation for making sure -on the client-side- that form values are just as expected.
jQuery.validity is an elegant and powerful jQuery plug-in you can use to setup client-side form validation. Instead of writing validation manually or balancing some unwieldy server-side framework, validity allows you to design client-side validation in a manner that feels natural and straightforward.
jQuery.validity is easy to learn and use. It’s totally appropriate in simple validation scenarios, but it’s also designed to cleanly and naturally tackle more complex, dynamic, or conditional scenarios.
jQuery.validity takes advantage of jQuery’s selector engine to perform validation on logical groupings of inputs, making it declarative and clean. This means that the inputs on a page can be added, removed, or changed and validation will still work without reconfiguration.
jQuery.validity is designed to give you total control over how validation messages appear, so you can easily adapt the way validation errors are displayed to the look and feel of your site.
The plugin also gives full control over how validation messages will appear which makes it possible to match the look and feel of your site.
There are various ready-to-use rules for e-mail, date, number, URL, time, phone, zip, etc.
And, there are lots of logical operators like: lessThanOrEqualTo, maxLength, nonHtml, sumMax and more to create any custom rules.