Frameworks and extensibility

I once heard Drupal described as analogous to Lego building blocks in that Lego blocks of all shapes and sizes; what can be created is limited only by your imagination. Many people have attempted to define what Drupal is. While a clear definition may help people understand when and how to adopt Drupal, if Drupal is of interest to them, or if Drupal can help them deliver a specific solution effectively, this is not a constructive way to understand what Drupal is.

Drupal is a tool. What is delivered with the tool can vary drastically. That is why the Lego analogy works. With Lego blocks, you can build a house, a car, a Star Wars figure… practically anything. Lego blocks empower a builder to create what they want to create. Often, people want a clear definition of Drupal. Is it a house, a car, or a Star Wars figure? No – it is a tool that helps you create the digital experiences you want to build. While I understand a desire to define what Drupal can be used for, looking at Drupal in this manner can be significantly limiting.

Drupal grew in popularity as a CMS. Drupal empowered site builders by offering a user interface for configuring structured content and serving that structured content as rendered HTML. Imagine a system that can be used to both create and deliver websites. Drupal offers that. Content is stored persistently by authors and then rendered for site visitors dynamically. Drupal is an application developed in PHP that leverages a database storage backend. Older CMSs simply managed static files, whereas Drupal is a functional system that can be programmed to manage content. Page requests do not correspond to static files; instead, they are dynamically processed by Drupal. The system interprets a URL, parameters, and sessions to deliver a unique, generated result back to the browser at the time the request was made. Some requests get content, others serve the user interface to manage content. Drupal handles all of that.

However, Drupal can do much more than basic content management. Out of the box, the core of Drupal delivers many features that allow it to be configured for conventional content management. This includes structured content, WYSIWYG, media/static file management, caching, rendering content displays, API-based content delivery, and more. However, Drupal also comes with a highly extensible framework that allows for it to be customized. Given Drupal is open source, community members have contributed their customizations back to the open-source community as projects that can be downloaded and installed on any Drupal application.

The goal of this book is to show how Drupal, its out-of-the-box features, and contributed projects can be built and configured to deliver amazing digital experiences. Like a large box of Lego blocks, the aim of this book is not to define exactly what can be built but to show you how to use the tool to accomplish a large number of potential outcomes. What you do is only bound by your imagination.