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)

Queues

It's finally time to talk a bit about the Queue API, how it works, and what its main components are; the theory, basically. We will do this before diving into code examples which we all thoroughly enjoy.

Introduction to the Queue API

The main purpose of the Queue API is to provide a way for us to add items to a queue in order to have them processed at a later time. In charge of processing these items are the queue worker plugins, which can be enlisted either automatically by the Drupal cron, manually (programmatically) by us, or by Drush. We will look at an example of all three.

The central player in this API is an implementation of the QueueInterface, which is the actual queue into which we put items. There are...