CakePHP is a great framework for rapid development of web based applications that serves well the principles of DRY (Do not Repeat Yourself). However unlike other web frameworks, CakePHP is not (and probably will not) fully AJAX based (for instance, you could check the list of PHP Ajax frameworks or try some Java/Python implementations such as Google Web Toolkit and Pyjamas).
In no way the statement above means that you cannot do some flexible and dynamic client-side calls into your CakePHP site. You could freely use plain Javascript in your views, use the JS helper of CakePHP or add some prototype/jQuery library and take advantage of its features. Beyond all that possibilities you could use one more helper of Cake - the AJAX helper. The AJAX helper provides an intuitive interface for maintaining some standard task with only few lines of code.
Some of the methods that you can use with the Ajax helper:
- link
- remoteFunction
- form
- observeField
- autoComplete
- drag & drop
and few more that you could find in the link above.
The standard 1.2 implementation expects prototype and scriptaculous in order to run properly. However you could easily replace them with jQuery (and jQuery UI) libraries. Some examples on that: http://www.cakephp.bee.pl/