Use the Configuration API to access configuration data stored by a module, provide default configuration, create settings forms, and other tasks such as overriding settings for a local environment.
Controllers
TopicControllers are the portion of a Drupal module that handle responding to an incoming request with the appropriate response data.
CSS in Drupal
TopicCascading Style Sheets (CSS) files are added as an asset library through a theme’s libraries configuration file. HTML attributes, including classes and IDs, are commonly added in template files with Twig.
Dependency Injection
TopicDependency injection is a design pattern commonly used in object-oriented software architectures in order to support Inversion of Control.
Drupal Console
TopicDrupal Console provides a command line utility for performing common site administration tasks, code generation scaffolding, and a Read-Evaluate-Print-Loop for interacting with your Drupal site.
Object-Oriented PHP
TopicObject-oriented PHP utilizes classes and objects to organize code into reusable chunks. This approach helps us organize complex applications, such as Drupal, into modular code called classes that can be reused across the entire system.
Routing
TopicDrupal's Routing API maps the URL of an incoming request to the code responsible for generating the content that is rendered in response.
Security
TopicKeeping a Drupal site secure requires monitoring security announcements, performing regular updates, and knowing how to properly use Drupal’s APIs to write secure code.
Services
TopicServices are objects that encapsulate the code for performing specific tasks in a reusable and decoupled way.
Twig is a template engine for PHP, which is the language used in Drupal. Twig can be used to design templates in generic PHP applications as well as Drupal themes.
Drupal Composer Project
TopicThe Drupal Composer Project provides a scaffold for starting a new Drupal project and managing that project's dependencies with Composer. It was created before the drupal/recommended-project Composer project template was developed, which is the current best practice method for creating a new Drupal site with Composer.
Symfony
TopicSymfony is a set of reusable PHP components, and a framework for building PHP applications. Drupal makes use of various Symfony components.
YAML
TopicYAML, which stands for YAML Ain't Markup Language, is a human-readable data serialization format that's been widely adopted in a variety of use cases in Drupal.
Performance and scalability determine how fast your application can serve a page and to how many users at a time.
Events
TopicEvents are one of the ways that module developers can alter or extend Drupal without modifying existing code.
Caching in Drupal
TopicCaching in Drupal is controlled by Drupal's Cache API which is used to store any type of data on a permanent or temporary basis. Some types of data tend to take a long time to compute, but utilizing the Cache API in your module can help your site load data more quickly.
Learn about resources to guide you through the process of updating a module or theme to the latest version of Drupal.
In Drupal’s core library there are a number of utility functions and classes that, as a module developer, you will find make your task easier or less tedious.
Plugins (Plugin API)
TopicPlugins are one of the ways that module developers can write code that extends Drupal. The Drupal Plugin API allows a module to provide functionality in an extensible, object-oriented way.
Upgrading is the process of moving your site from a previous major version of Drupal to a newer version, for example from Drupal 7 to Drupal 8 or Drupal 9 to Drupal 10.