As a developer, I hate writing similar code for the same process over and over again. Just like highly optimized database design, developers should always try to write code as efficiently as possible.
I’m working on a project where I use YUI and CakePHP to fill multiple combo boxes on a page using Json data. At first, I wrote separate code with the same functionality for each combo box. Every time I needed to change the functionality, I had to change it for each combo box. After doing this multiple times, I decided to combine the functionality on both the front-end (YUI) and the back-end (CakePHP).