I've worked on a couple of older projects recently where previous developers had implemented only server-side validation (bad for UX) or, even worse, a mix of both client and server-side where the rules had come out of sync so decided to do something about it. Some of the code isn't the most logical, but this library helps to make sure everything stays in sync. Thoughts?
Looks clean, do you plan to implement any other client-side validators yourself?
Maybe you can add helpers to generate the HTML elements as well, since HTML5 adds some attributes that allow the browser to validate e.g. email or required.
I've only really used jQuery Validation, hence it's intergration but there's no reason why different implementations cannot be added. What JS validation libraries would you want to see added?
I usually use validation as an example of why it would be worth to use the same language. It would enable, among other things, to write the validation logic once. I find libraries like this one to be a hack used to get some language to share validation code between client and server.
This is why I use Node/Express now; I use the same validation code client/server and where the client code, if required, uses socket.io for things which would normally only work on the server (validations using the db for instance).
ValidForm Builder is a lot easier to use imho. Generates both server and client side validation including the form itself.