Book Image

Drupal 9 Module Development - Third Edition

By : Daniel Sipos
Book Image

Drupal 9 Module Development - Third Edition

By: Daniel Sipos

Overview of this book

With its latest release, Drupal 9, the popular open source CMS platform has been updated with new functionalities for building complex Drupal apps with ease. This third edition of the Drupal Module Development guide covers these new Drupal features, helping you to stay on top of code deprecations and the changing architecture with every release. The book starts by introducing you to the Drupal 9 architecture and its subsystems before showing you how to create your first module with basic functionality. You’ll explore the Drupal logging and mailing systems, learn how to output data using the theme layer, and work with menus and links programmatically. Once you’ve understood the different kinds of data storage, this Drupal guide will demonstrate how to create custom entities and field types and leverage the Database API for lower-level database queries. You’ll also learn how to introduce JavaScript into your module, work with various file systems, and ensure that your code works on multilingual sites. Finally, you’ll work with Views, create automated tests for your functionality, and write secure code. By the end of the book, you’ll have learned how to develop custom modules that can provide solutions to complex business problems, and who knows, maybe you’ll even contribute to the Drupal community!
Table of Contents (20 chapters)
3
Chapter 3: Logging and Mailing

SQL Injection

SQL Injection still remains a very popular vector attack on vulnerable applications that incorrectly make use of database drivers. Luckily, by using the Drupal database abstraction layer, we go a long way toward ensuring protection against such vulnerabilities. All we have to do is use it correctly.

When it comes to Entity queries, there isn't much we can do wrong. However, when using the Database API directly, as we did in Chapter 8, The Database API, we have to pay attention.

Most of the time, vulnerabilities have to do with improper placeholder management. For example, we should never do things like this:

$database->query('SELECT [column] FROM {table} t WHERE t.name = ' . $variable);  

This is regardless of what $variable is—direct user input or otherwise. Because by using that direct concatenation, malicious users may inject their own instructions and complete the statement in a different way than intended. Instead, we...