Logiklagren

Logiklagren is a term used in software architecture to describe the layer of an application that implements business logic and rules, separating it from presentation and data storage. The layer is responsible for enforcing domain rules, validating input, coordinating workflows, and maintaining invariants across operations.

In a typical multi-tier design, logiklagren sits between the presentation layer (the user interface) and the data access layer (persistence). It may include domain models, domain services, and application services. The domain model captures key entities and aggregates; domain services coordinate tasks, enforce invariants, and orchestrate calls to repositories and external systems. The service layer can also expose operations to the presentation layer while keeping business rules centralized.

Patterns commonly associated with logiklagren include Domain-Driven Design, the Service Layer pattern, and the use of business rules engines. Implementations vary: some systems place more logic in domain objects (rich domain model), while others rely on a dedicated service layer or a combination of both. In distributed architectures, logic may be partitioned into multiple services that encapsulate distinct business capabilities.

Challenges include avoiding leakage of presentation concerns into the logic layer, addressing performance considerations, and managing cross-cutting concerns such as security, transactions, and logging. Testing focuses on unit testing of domain rules and integration testing of workflows and service orchestration.

See also: domain-driven design, business logic, service layer, domain model, n-tier architecture. The term is widely used in Swedish-language materials and is often equivalent to the English concept of the business logic layer.