Using open source software to design, develop, and deploying a collaborative Web site, Part 5: Getting started with Drupal - IBM's Series of articles brings a nice introduction to Drupal in Part 5.

Introduction

This article gives you an overview of the Drupal content management system. We'll describe the common building blocks and discuss some common assumptions of the Drupal approach. It is helpful to understand core concepts and basic Drupal terminology as you go through this article and beyond.

The Drupal content management system maintains its content in a database. Within the database, the content is stored as nodes and other high-level objects, such as users and comments. There are a variety of different, predefined node types including stories, blogs, and polls.

Drupal constructs pages that contain one or more pieces of information in the form of nodes, blocks, and other items. Each page is typically organized around a center column of content with left and right side-bars, and a header and footer. With the exception of the center column of content, the other areas are optional.

The center column is used to display the main site content; the optional areas are for additional content. Drupal uses blocks to fill the optional areas with small pieces of information. The optional areas typically hold navigation links (for example, most popular nodes) and other abbreviated content. Just like any content, blocks can be made dependent on the user's role, providing a customized view of the information.

One of the most important features of Drupal is the ability to extend the types of nodes available, such as your application-specific content, by writing custom node modules.

Modules are extensions to Drupal that implement one or more hooks from a predefined interface. Hooks define user permissions, interact with the database, and provide an interface to edit the content.

The menu system controls the navigation of the Web site and is fully customizable through the user interface. By contrast, the menu hook function controls how URLs are formed, how URLs are translated, and what function a specific URL will call. Newcomers to Drupal are frequently misled by the name of this hook function because it is not really about menus. So be aware that this is a possible point of confusion when dealing with "menus" in Drupal.

The separation of content from presentation is enabled by a system that themes the pages based on templates. Most content can easily be structured and styled by defining a set of template, or tpl, files and theme functions.

Nodes can be organized into categories or taxonomies. Forums are an example of hierarchical content within a taxonomy.

All the content is accessed through a permissions system to control the access and editing of content on the Web site.

It is important to understand that we are presenting the steps we took to implement the required functions for our online community site. This information should not be interpreted as a rigid set of development guidelines that must be followed to develop a successful or functional Drupal site. Instead, use this article as a point of comparison during the development of your site.