Book Image

Drupal 8 Module Development - Second Edition

By : Daniel Sipos
Book Image

Drupal 8 Module Development - Second Edition

By: Daniel Sipos

Overview of this book

Drupal 8 comes with a release cycle that allows for new functionality to be added at a much faster pace. However, this also means code deprecations and changing architecture that you need to stay on top of. This book updates the first edition and includes the new functionality introduced in versions up to, and including 8.7. The book will first introduce you to the Drupal 8 architecture and its subsystems before diving into creating your first module with basic functionality. 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. 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, you will have learned how to develop your own custom module that can provide complex business solutions. And who knows, maybe you’ll even contribute it back to the Drupal community. Foreword by Dries Buytaert, founder of Drupal.
Table of Contents (20 chapters)

Introduction to Caching

The first thing I would like to mention before getting into the meat of the Cache API is that this subsystem is one of the best documented ones (at the time of writing). You can check out the main entry page (https://www.drupal.org/docs/8/api/cache-api/cache-api) and I recommend keeping it close by when developing.

The Cache system in Drupal 8 provides the API needed to handle the creation, storage, and invalidation of cached data. From a storage perspective, it is extensible, allowing us to write our own custom cache backends (CacheBackendInterface). By default, however, cache data gets stored in the database and hence the default backend is DatabaseBackend. Going forward, we will focus only on this implementation since it is the most commonly used one, especially when starting a new project. Quite often though, once the site becomes more complex, alternative...