DRY Principles in Drupal

Apply DRY (Don't Repeat Yourself) principles to Drupal development. Understand how Drupal's architecture supports code reuse through configuration, services, base classes, traits, plugins, templates, and components.

I need to...

I need to...	Guide	Summary
Understand DRY in Drupal's architecture	DRY in Drupal Overview	When making architectural decisions about code organization in Drupal projects — deciding between configuration vs code, services vs static calls, base classes vs traits, plugins vs custom implementations, or template inheritance vs…
Use config as single source of truth	Config as Single Source of Truth	Whenever you need to store site settings, entity definitions, field configurations, view definitions, or any setting that should be consistent across environments.
Extract shared logic into services	Services for Shared Logic	When you have business logic, API integrations, calculations, or data transformations that are used in multiple places (controllers, forms, event subscribers, Drush commands).
Extend base classes properly	Base Classes and Inheritance	When you have multiple classes of the same type (entities, forms, blocks, controllers) that share common patterns or need to override specific base functionality.
Use traits for cross-cutting concerns	Traits for Cross-Cutting Concerns	When you need to share functionality across classes that don't share the same inheritance hierarchy, or when you want to compose behaviors without deep inheritance.
Reuse plugin patterns	Plugin Reuse Patterns	When you need extensible, discoverable, swappable components (blocks, field types, filters, conditions, actions), or when multiple plugins share common patterns.
Leverage Twig template inheritance	Twig Template Inheritance	When you need to override theme templates but want to reuse most of the structure, changing only specific sections.
Build reusable UI components with SDC	SDC Component Reuse	When you need reusable UI components (buttons, cards, modals, forms) used across multiple pages, content types, or blocks. SDCs (Single Directory Components) are Drupal's native component system (core since 10.3).
Create reusable render patterns	Render Array Patterns	When you need consistent rendering patterns across multiple controllers, blocks, or preprocess functions. Render arrays are Drupal's structured way to describe renderable content.
Share hook and event logic	Hook and Event Reuse	When you need to respond to system events (entity operations, form alterations, request processing) without duplicating logic across similar hooks or event subscribers.
DRY across environments	Config Split and Environments	When you need different configuration across environments (dev modules in dev only, production API keys in prod only) without duplicating config or managing it manually.
Use recipes for config distribution	Recipes for Reusable Config	When you want to package and distribute reusable configuration setups (content types, fields, views, modules) across multiple Drupal sites or projects. Recipes are Drupal 11's successor to installation profiles and features.
Reuse logic in CLI and web contexts	Drush and CLI Reuse	When you need to perform operations via command line (cron, batch processing, deployments) and want to reuse the same business logic that exists in web controllers/forms.
Avoid common over-DRY mistakes	Over-DRY Anti-Patterns	When deciding whether to abstract or duplicate. Over-DRY is worse than under-DRY because wrong abstractions are harder to remove than duplication.
Get a decision framework	Best Practices Decision Framework	When making any decision about abstracting, reusing, or duplicating code in Drupal.
Find reference code examples	Code Reference Map