MediatRstyle

MediatRstyle is a mediator-based software design approach that emphasizes decoupled communication through explicit request and notification messages, inspired by the MediatR library commonly used in .NET. It is not a formal specification but a descriptive term for an implementation style that centers a central mediator to coordinate handling of requests and notifications.

Core concepts include a central mediator that receives requests or notifications, handlers that implement business logic, and a registration mechanism that wires the mediator to concrete handlers, often through dependency injection. Clients issue requests to the mediator instead of calling services directly; the mediator resolves the appropriate handler and delegates the work, returning a result or publishing notifications.

Message types in MediatRstyle typically include requests (encompassing commands and queries) and notifications. A request is mapped to a single handler that provides a response; a notification can trigger multiple handlers without a return value. Pipelines or behaviors can be inserted around handling to perform cross-cutting concerns such as validation, logging, or authorization.

Advantages of this style include loose coupling between components, improved testability, and clearer separation of concerns. Potential challenges include added complexity, potential difficulty tracing the flow of control, and possible overhead from indirection. The pattern benefits from strong typing and explicit contracts between senders and handlers.

Common use cases include domain-driven design, CQRS, and event-driven architectures where components should remain independent of concrete implementations. It is compatible with many platforms and languages that support a mediator concept and dependency injection.

Relation to MediatR: the term describes approaches similar to MediatR’s API and workflow without implying a specific library. When adopting MediatRstyle, teams should consider platform compatibility, performance, and maintainability.