An Introduction to Drupal Module Development

With its extensive framework and flexible structure, modules allow you to take Drupal into entirely new directions. Modules in Drupal can automate various PP routines, allowing you to create a specific piece of software within your larger CMS. The code is executed through defined hooks (or executable areas) within the application, so you can utilize native PHP code or APIs to create a variety of Drupal features. In order to understand the potential, construction and options for Drupal module development, it’s important to understand how hooks work.

Simply, hooks provide a nesting function which provides data and inputs into modules. Since modules add onto the basic content delivery for Drupal, hooks provide the core basis for coding information into Drupal modules. The coding standards follow along these parameters:

Module name : hook_name()

One common example for Drupal modules is coding unique social applications where you can connect to the core internal Drupal API based upon existing user data. While you can find a wide variety of existing Drupal modules, some customizations may not have their own existing solution. In these cases you’ll want to invest in developing a unique, custom module for Drupal. When searching for a solution make sure you evaluate the existing Drupal modules to identify any potential pre-existing solutions that meet your needs: http://drupal.org/project/Modules

Once you have evaluated the solutions to find any valuable code you can begin with a schematic outline of the module. A schema should have a variety of steps, beginning with annotation of the requirements, including user data and content pieces, as well as necessary database development. There are a variety of variables you can utilize to pull into the module. For example if we wanted to write a module that simulated the “wall” on many popular social network we could utilize the following variables:

Rid (role ID)

UID (user ID)

Asg_time (time of post)

post (posts sent by mail)

By creating a wireframe with the various design pieces mapped to individual segments in the module, you can more easily build out the module framework. At the core of Drupal’s modules are .info files which store the basic hook information for the software. The .info files pull in hooks (and API calls) into a .module file which forms the core of the application. Importantly, forms and fields on modules are designed to scale, allowing you to update with new elements and information.

The modules are fully compatible with JavaScript and CSS, so you can customize the look and feel of the module presentation to match the site as well. One impressive option is the ability to update the form inputs and outputs using AJAX, which can allow for real time refreshing and entry of data without causing any load problems on the page.  This function works by building the form and retrieving and writing it from cache to update the elements. With AJAX you can have real time updates for your module that allows you to seamlessly integrate new features into your application in real time.