Because ajax validation for forms in the current version of the CakePHP framework is a international issue I thought lets write this one in english. 
I have been using Cakephp for over one year now and every time I'm building an application with it I'm facing the ajax validation problem. 
The problem is that Cakephp doesn't have AJAX validation. There are several self build plugins for this which all require some serious PHP and jquery/Javascript skills.
Most of these plugins let you make new files or extra (duplicated) javascript rules for the validation. 
Extra files en duplicated validation rules? Yeah, that is not the way to go for me. :)


So my goal was writing a new javascript library that does most of the work and which doen't require extra files or duplicated validation lines and keep most of the CakePHP code intact.
How Cakephp handles validation for forms is really nicely done throught the models. The plugin I've writen keeps that all intact. I hope you can use it for you own project, drop a comment if so! 

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AJAX Validation for CAKEPHP
	 	
- Make sure you make up your form the Cake way in your views.
- add this line in your controller: var $components  = array('RequestHandler');
- I'm using an empty layout called 'ajax' for returning the AJAX response ( $this->layout = 'ajax'; ), create the file /app/views/layouts/ajax.ctp with only this inside it: <?php echo $content_for_layout; ?>
- to add any validation rules you can use the CAKEPHP way as described here: http://book.cakephp.org/view/1143/Data-Validation
- the value of this two lines ( in add.tp) you need to changes to your ID's
.- var formId    = '#addModel';  // id of your form <form id=""
.- var button    = '#submit';  // id of your submit <input id="" type="submit"

Need help? contact me @MelvinvdBout