Extending Drupal with Custom Code
The greatest component of Drupal is its extensibility through modules. In this chapter, we will explore how to create a custom module that can be installed on your Drupal site. This chapter will explain how PSR-4 autoloading works with extensions and how to leverage class autoloading. You will be able to create a controller for a custom page and specify additional permissions to check whether the user has them. You will also understand what hooks and events in Drupal are, and how to interact with them. This chapter also lays the foundations for the following chapters.
The following recipes will be covered in this chapter:
- Creating a module
- Providing configuration settings for your module
- Defining permissions and checking whether a user has access
- Hooking into Drupal to react to entity changes
- Creating an event subscriber to react to events
- Creating a custom Drush command
