Book Image

Drupal 8 Module Development

By : Daniel Sipos
Book Image

Drupal 8 Module Development

By: Daniel Sipos

Overview of this book

Drupal is an open source web-based content management system (CMS) that can be used for building anything from simple websites to complex applications. It enables individuals and organizations to build platforms that engage users and deliver the right content at the right time. Drupal 8 is an exciting new development in the Drupal community. However, the differences from the previous version are substantial and this can put quite some pressure on Drupal 7 developers that need to catch up. This book aims to help such developers in getting up to speed with Drupal 8 module development. The book first introduces you to the Drupal 8 architecture and its subsystems before diving into creating your first module with basic functionality. Building upon that, you will cover many core APIs and functionalities available to module developers. You will work with the Drupal logging and mailing systems, learn how to output data using the theme layer and work with menus and links programmatically. Then, you will learn how to work with different kinds of data storages, create custom entities, field types and leverage the Database API for lower level database queries. Moreover, you will learn about the Drupal 8 access system and caching layer as well as the APIs used for data processing (queues and batches). You will further see how to introduce javascript into your module, work with the various file systems and ensure the code you write works on multilingual sites. Finally, you will learn how to programmatically work with Views, write automated tests for your functionality and also write secure code in general. By the end of the book, you will have learned how to develop your own custom module from scratch that can help solve a small problem or even provide complex functionality. And who knows, maybe you’ll even contribute it back to the Drupal community.
Table of Contents (19 chapters)

Developing for Drupal 8

Drupal is a web-based Content Management System (CMS). While it is useful out of the box, it is designed with developers in mind. The purpose of this book is to explain how Drupal can be extended in many ways and for many purposes. To this end, the version we will use will be the latest one at the time of writing this book--Drupal 8.2. In this book, we will cover a wide range of development topics. We'll discuss how to create a Drupal 8 module, and as we go through the chapters, many concepts and tips that will help you build what you need will be introduced. The goal is not only to explain how things work but also to go through some examples to demonstrate them. Since no book can contain everything, I hope that after reading this book, you'll be able to expand on this knowledge on your own using the resources I reference and by looking into the Drupal code yourself. As helpful as such a book can be for learning any kind of software development, if you really want to progress, you will need to apply the knowledge you learned and explore the source code yourself. Only by doing this you will be able to understand complex systems with many dependencies and layers.

This chapter introduces the terminology, tools, and processes for developing Drupal 8. While subsequent chapters focus on code, this chapter focuses on concepts. We'll talk about the architecture of Drupal and how you can hook into Drupal at strategic places to extend it for accomplishing new tasks.

The following are the major topics we will be covering in this chapter:

  • An introduction to Drupal development
  • Drupal 8 architecture
  • The major subsystems
  • Tools for developing in Drupal

By the end of this chapter, you will understand the architectural aspects of Drupal and be ready to start writing code.