FreePascal/Lazarus SOLID Patterns

Implement SOLID design patterns in FreePascal/Lazarus by using guided templates for repository, factory, and strategy patterns with constructor injection. This standardizes development and promotes clean, modular code across domain entities and application layers.

Structure a clean architecture domain layer in Lazarus by defining domain entities, creating repository interfaces, and orchestrating business logic through a service layer. This approach reduces coupling and promotes testable, maintainable architectures.

Use constructor injection for service layers in FreePascal by passing repository interfaces directly into service constructors. This encapsulates dependency management, standardizes wiring, and ensures business logic remains decoupled from data access implementations.

The SOLID patterns approach supports interchangeable algorithms like tax calculations through the strategy pattern. This allows you to swap computational logic dynamically without modifying the core service structure.

You can use the repository pattern for data access in FreePascal without heavy dependencies by defining repository interfaces and lightweight concrete implementations. This abstracts data access, reducing code smells and coupling.

Use the factory pattern to assemble repositories and services in Lazarus when you need centralized wiring of application layers. Factories construct and inject dependencies, ensuring consistent initialization of domain entities and services.