Elgg/Elgg — pull request #319 by sembrestels (2012-07-13 23:50:50+00:00)
Title: Refs #4662. First workarroud forms validation with javascript.

This merge isn't ready to merge yet.

It present a completely working patch for register form, and we have to discuss about the functions, if we put them in a library and how we call and work with them.

Things to do:
* Add new ajax end points to be able to call `validate_username`, `validate_password` and `validate_email_address` PHP functions.
* Add a hook structure to the new javascript functions.

Things to discuss:
* Improve the way it is deployed and think in plugin extensions.
* Move to a library.
* Make as easy as add an `elgg-validate-*` CSS class to validate a field.
* Use it in the other plugin forms (edit, etc) to check required fields and whatever.
* Study more use cases.