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)

Common theme hooks

In this section, we will look at three common theme hooks that come with Drupal core that you are likely to use quite often. The best way to understand them is, of course, by referring to an example of how to use them. So, let's get to it.

Lists

One of the most common HTML constructs are lists (ordered or unordered), and any web application ends up having many of them, either for listing items or for components that do not even look like lists, but for the purposes of marking up, an ul or ol fits the bill best. Luckily, Drupal has always had the item_list theme hook which is flexible enough to allow us to use it in almost all cases.

The item_list theme hook is defined inside drupal_common_theme(), is...