Drupal is a massively popular open source CMS.  Many web developers have found that they can enhance the look and feel of their sites by adding some JavaScript to their Drupal theme. 

The Drupal 7 development team has made this easier by including methods for implementing JavaScript.  According to the Drupal Community Documentation, developers should follow these two guidelines when adding JavaScript to Drupal themes – firstly, JavaScript should only be used as an adjunct or modifier of page elements, it cannot be used to replace anything.  Pages should be completely functional without JavaScript.  Secondly, JavaScript is not to be hard-coded into pages, only attached dynamically when the needed support is available.

Implementing JavaScript in Drupal

Probably the easiest way to get into writing JavaScript for Drupal is to download the JavaScript Libraries Manager module.  This allows you to enable the JavaScript libraries that come with Drupal, as well as link to and upload additional libraries and scripts.

To add a JavaScript file, inline code, or setting to a theme or module, you can use the PHP function drupal_add_js(), where 'js' stands for JavaScript.  This function takes 5 parameters which specify where the file is, what type it is, and how it will be used.  To fully understand them take a look at the official Drupal API reference page.

Adding Effects with JavaScript

There are many interesting ways to use JavaScript to make your website look more interesting, such as rotating images.  To cause your images to rotate, organize them in a single folder and be sure to size them according to your needs.  Also, collect any links that you will want to associate with the images.

Next, you will need to create a JavaScript file with the appropriate code, which can be found here.  Create the file as normal (paste the code into a text editor and save it as .js) and then add the file to your Drupal theme as explained above.

To get a sliding image effect, follow the same instructions with some JavaScript image slider code, which can be found here.

There are many ways in which Drupal and JavaScript can interact, and implementation should only be done by a qualified developer.  For more information, see the official Managing JavaScript In Drupal 7 page, containing tons of useful information and comments. 

For technical JavaScript coding standards used in Drupal, see this coding reference, and for a large database of free JavaScript code, see JavaScript Free Code.

Image by Dmitry Baranovskiy