AJAX is a great technology, and while I know what I’m doing, sometimes even I am amazed at how difficult it is. You’ve got HTML, Javascript, PHP, and usually database tables to get right. If any one of those isn’t working it won’t work.

If you don’t already have good debugging skills, I wouldn’t even try it. I very much try to integrate my debugging in with my development to save time. For instance, I have a function that checks to make sure a database call went OK. If not it sends an ajax response with the query and the error string. My calls to AJAX are always prepared to receive and display that error. Even my CSS for the page even handles displaying the returned error string in the most clear way possible. This is code I can use again and again in all my plugins, and if I didn’t reuse it I would never get anything done..

Now that I’m getting it down, it’s so nice. I love AJAX. But the more I work on the web the more I see we need a replacement for JavaScript. I mean most of the language is fine, but it needs to be a real language with the standard object oriented features implemented in the standard way: class, public, private, protected, property getters and setters, etc. The prototype keyword needs to be completely removed from the language. JavaScript and PHP need to align such that AJAX is a natural part of both languages. It’s possible, but the web is a funny thing and its technologies have a heck of a time moving forward.

wp_enqueue_script and wp_enqueue_style

These are two awesome functions to get your plugin scripts and styles included in the right order taking into account dependencies, and so easy to use. I love them, I’m surprised I hadn’t found them until today. I changed a bunch of my plugins to use them and it also helped me to use the WordPress version of jQuery

(function($) { … } ) (jQuery)

Use this in WordPress plugins that use jQuery if you want to use the dollar sign shortcut. WordPress disables that because of a conflict, but this will let you use it without interfering with anything else. Put your code where the ellipsis is. Javascript is so bizarre to me, I honestly don’t have any idea why this works. I’m very curious though.

Be sure to put function declarations you need to call from other places outside this block though, this can go just inside the body of the function.

jQuery and AJAX

jQuery makes AJAX a lot less painful and worry free. I can’t imagine doing it any other way.