AJAX / Dynamic Content and Interactive Forms

Essentially, AJAX is an acronym for Asynchronous JavaScript and XML, and it is the technique of using JavaScript and XML to send and receive data between a web browser and a web server. The biggest advantage this technique has is that you can dynamically update a piece of content on your web page or web form with data from the server (preferably formatted in XML), without forcing the entire page to reload. The implementation of this technique has made it obvious to many web developers that they can start making advanced web applications (sometimes called RIAs—Rich Interface Applications) that work and feel more like software applications, instead of like web pages.

Keep in mind that the word AJAX is starting to have its own meaning (as you'll also note its occasional use here as well as all over the web as a proper noun, rather than an all-cap acronym). For example, a Microsoft web developer may use VBScript instead of JavaScript to serve up Access Database data that is transformed into JSON (not XML) using a .NET server-side script. Today, that guy's site would still be considered an AJAX site, rather than an AVAJ site (yep, AJAX just sounds cooler).

In fact, it's getting to the point where just about anything on a website (that isn't in Flash) that slides, moves, fades, or pops up without rendering a new browser window is considered an 'Ajaxy' site. In truth, a large portion of these sites don't truly qualify as using AJAX, they're just using straight-up JavaScripting. Generally, if you use cool JavaScripts in your WordPress site, it will probably be considered 'Ajaxy', despite not being asynchronous or using any XML.

Want more info on this AJAX business? The w3schools site has an excellent introduction to AJAX, explaining it in straight-forward, simple terms. They even have a couple of great tutorials that are fun and easy to accomplish, even if you only have a little HTML, JavaScript, and server-side script (PHP or ASP) experience (no XML experience required) (http://w3schools.com/ajax/).

You Still Want AJAX on Your Site?

OK! You're here and reading this article because you want AJAX in your WordPress site. I only ask you take the just discussed into consideration and do one or more of the following to prepare.

Help your client assess their site's target users first. If everyone is web 2.0 aware, using newer browsers, and are fully mouse-able, then you'll have no problems, AJAX away. But if any of your users are inexperienced with RIA (Rich Interface Application) sites or have accessibility requirements, take some extra care. Again, it's not that you can't or shouldn't use AJAX techniques, just be sure to make allowances for these users. You can easily adjust your site's user expectations upfront, by explaining how to expect the interface to act. Again, you can also offer alternative solutions and themes for people with disabilities or browsers that can't accommodate the AJAX techniques.

Remember to check in with Don't Make Me Think, that Steve Krug book I for help with any interface usability questions you may run into. Also, if you're really interested in taking on some AJAX programming yourself, I highly recommend AJAX and PHP by Cristian Darie, Bogdan Brinzarea, Filip Chereches-Tosa, and Mihai Bucica. In it, you'll learn the ins and outs of AJAX development, including handling security issues. You'll also do some very cool stuff like make your own Google-style auto-suggest form and a drag-and-drop sortable list (and that's just two of the many fun things to learn in the book).

So, that said, you're now all equally warned and armed with the knowledgeable resources I can think to throw at you. Let's get to it; how exactly do you go about getting something 'Ajaxy' into your WordPress site?

Plug-ins and Widgets

In these next few sections we're going to cover plug-ins and widgets. Plug-ins and widgets are not a part of your theme. They are additional files with WordPress compatible PHP code that are installed separately into their own directories in your WordPress installation (again, not in your theme directory). Once installed, they are available to be used with any theme that is also installed in your WordPress installation.

Even though plug-ins and widgets are not the part of your theme, you might have to prepare your theme to be compatible with them. Let's review a bit about plug-ins and widgets first.


WordPress has been built to be a lean, no frills publishing platform. Its simplicity means that with a little coding and PHP know-how, you can easily expand WordPress's capabilities to tailor to your site's specific needs. Plug-ins were developed so that even without a little coding and PHP know-how, users could add extra features and functionality to their WordPress site painlessly, via the Administration Panel. These extra features can be just about anything—from enhancing the experience of your content and forms with AJAX, to adding self-updating 'listening/watching now' lists, Flickr feeds, Google Map info and Events Calendars; you name it, someone has probably written a WordPress plug-in for it.

Take a look at the WordPress Plug-in page to see what's available:



Widgets are basically just another plug-in! The widget plug-in was developed by AUTOMATTIC (http://automattic.com/code/widgets/), and it allows you to add many more kinds of self-updating content bits and other useful 'do-dads' to your WordPress site. Widgets are intended to be smaller and a little more contained than a full, stand-alone plug-in, and they usually display within the side bar of your theme (or wherever you want; don't panic if you're designing a theme without a sidebar).

If you're using WordPress version 2.2 and up, the widget plug-in has become a part of WordPress itself, so you no longer need to install it before installing widgets. Just look through the widget library on WordPress's widget blog and see what you'd like! (http://widgets.wordpress.com/)

Trying to download Widgets but the links keep taking you to Plug-in download pages? You'll find that many WordPress Widgets 'piggyback' on WordPress Plug-ins, meaning you'll need the full plug-in installed in order for the widget to work or the widget is an additional feature of the plug-in. So don't be confused when searching for widgets and all of a sudden you're directed to a plug-in page.

WordPress Widgets are intended to perform much the same way Mac OS's Dashboard Widgets and Windows Vista Gadgets work. They're there to offer you a quick overview of content or data and maybe let you access a small piece of often used functionality from within a full application or website, without having to take the time to launch the application or navigate to the website directly. In a nutshell, widgets can be very powerful, while at the same time, just don't expect too much.

Getting Your Theme Ready for Plug-ins and Widgets

In this article, we'll take a look at what needs to be done to prepare your theme for plugins and widgets.

Plug-in Preparations

Most WordPress Plug-ins can be installed and will work just fine with your theme, with no extra effort on your part. You'll generally upload the plug-in into your wp_content/plugins directory and activate it in your Administration Panel. Here are a few quick tips for getting a plug-in displaying well in your theme:

  1. When getting ready to work with a plug-in, read all the documentation provided with the plug-in before installing it and follow the developer's instructions for installing it (don't assume just because you've installed one plug-in, they all get installed the same way).
  2. Occasionally, a developer may mention the plug-in was made to work best with a specific theme, and/or the plug-in may generate content with XHTML markup containing a specific CSS id or class rule. In order to have maximum control over the plug-in's display, you might want to make sure your theme's stylesheet accommodates any id or class rules the plug-in outputs.
  3. If the developer mentions the plug-in works with say, the Kubrick theme, then, when you install the plug-in, view it using the Kubrick theme (or any other theme they say it works with), so you can see how the plug-in author intended the plug-in to display and work within the theme. You'll then be able to duplicate the appropriate appearance in your theme.

Installing the AJAX Comments Plug-ins

As I mentioned earlier, AJAX can really enhance the user's experience when it comes to forms. The most used form on a blog would be the comment form. Let's look at a plug-in that can really speed and tidy up the comment process. I'll be installing Mike Smullin's AJAX Comments Plug-in. You can get it from http://wordpress.smullindesign.com/plugins/ajax-comments.

If you can't spare the dollar that ol' Mike is asking for, you can also use Regua's AJAX Comment Posting plug-in (http://wordpress.org/extend/plugins/ajax-comment-posting/).

Regua's plug-in is good, but I just really like Mike Smullin's plug-in it's very light and works quickly. Well worth the dollar I spent on it. Here's the best part installing it:

Time For Action:

  1. Unzip and upload the ajax-comments directory into the wp-content/plugins directory.
  2. Go to Administrator | Plug-ins panel and Activate it.
  3. Use it. That's it! The user sees their comment updated immediately with a note that the comment is awaiting approval. It's nice for the moment and they feel 'heard', but you might not ever actually approve the comment depending on its content.
AJAX / Dynamic Content and Interactive Forms

Widget Preparations

Some plug-ins, like the widget plug-in (again you don't have to install this if you're using version WordPress 2.2 and up), do require your theme to go through some more formal preparation. You'll need to do the following to make your theme compatible with widgets (a.k.a 'Widgetized').

Time For Action:

  • Your side bar should ideally be set up using an unordered list format. If it is, you can add this code within your side bar: (If your sidebar is not set up using an unordered list format, ignore this step, but pay attention in step 3.)
<ul id="sidebar">
<?php if ( !function_exists('dynamic_sidebar')|| !dynamic_sidebar() ) : ?>
<li id="about">
<p>This is my blog.</p>
  • Because we deconstructed the default WordPress theme, based on the famous Kubrick theme, there is a funcitons.php file in our theme that already has the widgets registered for the sidebar. If by some chance you started completely from scratch or lost that file, you simply need to create a functions.php file in your themes folder and add this code to it:
if ( function_exists('register_sidebar') )
'before_widget' => '<li id="%1$s"
class="widget %2$s">',
'after_widget' => '</li>',
'before_title' => '<h2 class="widgettitle">',
'after_title' => '</h2>',
  • My problem is that my sidebar format is much customized and it's not in a simple unordered list. Plus, I have two sidebars. I'd want the second sidebar that holds my GoogleAdSense to contain a widget or two, but not my 'Table of Contents' sidebar. Not a problem! The code we entered above in the functions.php file helps us with our more traditional div-header-list structure. Add this code to your non-unordered list sidebar:
 <div id="sidebar">
<?php if ( !function_exists('dynamic_sidebar')
|| !dynamic_sidebar() ) : ?>
<div class="title">About</div>
<p>This is my blog.</p>
<div class="title">Links</div>
<li><a href="http://example.com">Example</a></li>
<?php endif; ?>
  • You've got two sidebars and you want them both to be dynamic? Instead of register_sidebar(), use register_sidebars(n), where n is the number of sidebars. Place them before the array bit of code if you're using a non-unordered list sidebar, like so:
if ( function_exists('register_sidebar') )
register_sidebar(n, array(
'before_widget' => '<li id="%1$s"
class="widget %2$s">',
'after_widget' => '</li>',
'before_title' => '<h2 class="widgettitle">',
'after_title' => '</h2>',

Then place the appropriate number in the dynamic_sidebar() function, starting with 1. For example:

 <div id="sidebar1">
<?php if ( !function_exists('dynamic_sidebar')
|| !dynamic_sidebar(1) ) : ?> <div class="title">About</div>

Your theme is now 'Widgetized'. For those of you who are looking forward to creating commercial themes be sure to tell everyone your theme is widget-friendly.

Like Widgets? Learn all about how to control their display in your theme and even develop your own. Check out AUTOMATTIC's Widget API Documentation at http://automattic.com/code/widgets/api/.

Additional Considerations: There are no concrete standards for widgets as of yet (though, the W3C is working on it (http://www.w3.org/TR/widgets/). Many WordPress widgets, like Google Reader, are flexible and can handle just about any size column. Some widgets may require a minimum column size! You may need to adjust your theme if the widget has an inflexible size. Some widgets (especially the ones that display monetized ads for your site) have display requirements and restrictions. Be sure to thoroughly investigate and research any widget you're interested in installing on your site.

Installing the Google Reader Widget

I do a lot of online reading, thank goodness for RSS feeds. I used to load-in all sorts of RSS feeds to my site to show people what I was reading, but that's not very accurate. It only shows what sites I usually go to, and what I might have read on that site. With all the new sites and blogs coming and going, I'd have old feeds left on my site, it got to be ugly, and I eventually stripped them all out.

Google Reader has a shared feed that lets people know exactly what I really have been reading and interested in. Thanks to this handy widget by James Wilson, I can share what I'm really reading, in real-time, quickly and easily. Once your theme is widget-compatible, it's pretty much just as simple to get a widget up and running as a plug-in. Get the Google Reader Widget from http://wordpress.org/extend/plugins/google-reader-widget/.

Time For Action:

  1. Unzip and drop googlereader.php file into the wp-content/plugins directory. (Depending on the widget, be sure to read the author's instructions. Some will want you to install to the wp-content/plugins directory and some will want you to install to the wp-content/plugins/widgets directory. You might have to create the widget directory.)
  2. Go to Administration | Plug-ins and Activate it.
  3. Go to Administration | Presentation | Widgets and drag the widget to your sidebar area.

  4. AJAX / Dynamic Content and Interactive Forms
  5. View it on your site.

I ran into a snag with the Google Reader Widget:

AJAX / Dynamic Content and Interactive Forms

I had to read the FAQ for the Google Reader Widget to learn that my hosting provider doesn't approve of the file_get_contents() method (http://wordpress.org/extend/plugins/google-reader-widget/faq/). So I had to modify my googlereader.php file at line 57 with the following workaround the widget author recommended:

 $ch = curl_init();
$timeout = 5; // set to zero for no timeout
curl_setopt ($ch, CURLOPT_URL, $uri);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
$stories = curl_exec($ch);

After making this tweak, the Widget worked fine:

AJAX / Dynamic Content and Interactive Forms

AJAX–It's Not Just for Your Site Users

I've already mentioned how, when applied properly, AJAX can aid in interface usability. WordPress attempts to take advantage of this within its Administration Panel by enhancing it with relevant information and compressing multiple page forms into one single-screen area. The following is a quick look at how WordPress uses AJAX to enhance it's Administration Panel forms:

AJAX / Dynamic Content and Interactive Forms


AJAX / Dynamic Content and Interactive Forms

Even if you haven't upgraded to WordPress 2.5, WordPress 2.3 makes use of AJAX on the widgets panel, allowing you to easily drag-and-drop to add and arrange your sidebar widgets. (For some reason, this has been redesigned in 2.5; I would have preferred if it had stayed the same).

AJAX / Dynamic Content and Interactive Forms


In addition to finding plug-ins and widgets that enhance your theme, you should consider looking for plug-ins that enhance your administration experience of WordPress! For example, if your WordPress site has a lot of pages and/or you display your page links as drop-down menus, then, Joel Starnes pageMash plug-in is for you.

pageMash is a great little plug-in that uses the MooTools framework and Moo.fx library. Instead of having to go into each individual page's editor view and then use the Page Parent view to manipulate your pages around into your hierarchical structure, this plug-in lets you reorder and assign pages as parents and sub-pages on-the-fly.

Time For Action:

  1. Download the pageMash plug-in from: http://wordpress.org/extend/plugins/pagemash/.
  2. Unzip the files and upload the pagemash directory to your /wp-content/plugins/ directory.
  3. Go to Administration | Plug-ins and Activate it. pageMash will then show up under the Administration | Manage tag.

I hope you can get an idea by the following screenshot about how much easier and quicker it is to arrange your WordPress pages with pageMash.

AJAX / Dynamic Content and Interactive Forms

The AJAX Factor

Aside from the many-interface enhancing, time-saving benefits of Ajax, sometimes you do just want to 'wow' your site visitors. It's easy to give your site an 'Ajaxy' feel, regardless of asynchronously updating it with server-side XML, just by sprucing up your interface with some snappy JavaScripts. The easiest way to get many of these effects is to reference a JavaScript library (sometimes called a toolkit or framework, depending on how robust the provider feels the code is). A few of the leading favorites in the AJAX community (in no particular order) are:

  1. Script.aculo.us: (http://script.aculo.us/)
  2. Prototype: (http://www.prototypejs.org/)
  3. jQuery: (http://jquery.com/)
  4. There's also:

  5. MooTools: (http://mootools.net/)
  6. Moo.fx: (http://moofx.mad4milk.net/)

Prototype is more of a framework and Script.aculo.us is more of an add-on toolkit or set of libraries for neat effects. In fact, Script.aculo.us references the Prototype framework, so your best bet is probably to use Script.aculo.us, but if you do work with it, be sure to check out Prototype's site and try to understand what that framework does.

Moo.fx is the smallest JavaScript effects library (boasting a 3k footprint), but again, it needs to be supported by the MooTools or Prototype frameworks.

jQuery is my personal favorite. It pretty much stands on its own without needing to be backed up by a more robust framework (like Prototype), but you can still do some very robust things with it, manipulating data and the DOM, plus it's packed with neat and cute visual effects, similar to Script.aculo.us.

Using JavaScript libraries like the above, you'll be able to implement their features and effects with simple calls into your WordPress posts and pages.

JavaScript Component Scripts

The fun doesn't stop there! What's that? You don't have time to go read up on how to use a JavaScript library like jQuery? Never fear! There are many other JavaScript effect components and libraries that are built using the libraries above. One of the most popular scripts out there that makes a big hit on any website is Lightbox JS:


Lightbox JS is a 'simple, unobtrusive script used to overlay images on the current page.' It's great, but it uses both the Prototype and Script.aculo.us libraries to achieve its effects. I also found that Lightbox was limited to only displaying images and a hair difficult to manipulate it to handle anything more than that. What if I wanted to display XHTML text, or markup containing YouTube videos, maybe even make an AJAX request to the server?

Enter Thickbox: http://jquery.com/demo/thickbox/

Thickbox is very similar to Lightbox JS. It uses only the jQuery library, and in addition to handling images similar to Lightbox JS, it can also handle in-line content, iFrame content, and AJAX content (be sure to check out the examples on the ThickBox page!). The downside—Thickbox doesn't do that smooth animation that Lightbox JS (version 2) does when images are different sizes. This is the trade-off I made when I decided it was more important to be able to display more than just images in my OpenSource Magazine theme.

Depending on your theme's design and what type of blog or site you're creating it for, you may opt to use Lightbox instead or something all together different! It's your theme, don't feel limited to what I specifically discuss in this book. I'll walk you through the process of installing ThickBox, but many 'Ajaxy' scripts that use these JavaScript libraries/frameworks are installed similarly. Just follow the instructions in the ReadMe files and you're on your way to an enhanced theme.

Time For Action:

  1. This is an extremely easy-to-implement script. After downloading it, add the key js and CSS files to your WordPress theme's home.php and header.php files using the bloginfo template tag to target your theme:
    <script type="text/javascript" src="<?php bloginfo
    ('template_directory'); ?>/js/jquery.js"></script>
    <script type="text/javascript" src="<?php bloginfo
    ('template_directory'); ?>/js/thickbox.js"></script>
  2. You'll also add in a call to the ThickBox CSS file:
    <style type="text/css" media="all">@import "<?php bloginfo
    ('template_directory'); ?>/thickbox.css";</style>
  3. Don't forget to upload the loadingAnimation.gif and macFFBgHack.png images to your theme directory and update the thickbox.js and thickbox.css files as per the ReadMe file instructions.
  4. Then, you can create a post (or page) in your Administration Panel and using the Code View add in basic href links around your image tags, like so:
    <a href='/wp-content/uploads/2008/04/inkscape2.jpg'
    class="thickbox" rel="inkscape"><img src="/wp-content/
    uploads/2008/04/inkscape2-150x150.jpg" alt="" title="inkscape2"
    width="150" height="150" class="alignnone size-thumbnail
    wp-image-15" /></a>
    <a href='/wp-content/uploads/2008/04/inkscape1.jpg'
    class="thickbox" rel="inkscape"><img src="/wp-content/
    uploads/2008/04/inkscape1-150x150.jpg" alt="" title="inkscape1"
    width="150" height="150" class="alignnone size-thumbnail
    wp-image-14" /></a>

I uploaded the images via WordPress's built-in up-loader and let WordPress create the thumbnails; I just added the captions to the title attribute, the rel attribute and the thickbox class by hand.

That's it!

AJAX / Dynamic Content and Interactive Forms


In this article, we reviewed a few ways to take advantage of AJAX on your WordPress site. We 'Wigitized' our theme and downloaded and installed a couple of useful plug-ins, and looked at using jQuery and ThickBox to enhance post and page content. Up next—let's take a look at some final design tips to working with WordPress.

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