Ajax validation support would also be a plus.
I want to define my form in PHP, call render(); and have all the HTML and user friendly javascript validation done for me based on what rules I add in PHP.
The best library I could find is http://www.jformer.com/ but it’s a mess, it uses iframes with a src of empty.html (for who knows why), and the way you process forms is awkward too.
Is there anything else like this?
Zend_Form from Zend Framework does this. Primarily it does server side validation of the forms, but you could extend it do basic client side validation as well. Using it in conjunction with Zend_Dojo may give you some additional client side capabilities as well.
You can also handle the forms via ajax or HTTP GET/POST. Also, you don’t need to use the entire Zend Framework to use Zend_Form, it would be possible to get it working as a standalone component.