In the application layer, the implementation of cqrs inside the service is shown. This allows you to configure integration with other services of msa in a synchronous or asynchronous manner. In addition to the integration event publisher, adapters for external communication are defined here as interfaces. Integration events that are issued to services in external contexts are defined here, domain events received by domain event handlers are processed, and these integration events are published through the integration event publisher. In addition, domain events generated by executing domain logic are handled through domain event handlers. The application layer depends on the domain layer and executes the domain logic of the domain model.
Here, when creating a domain object, the factory pattern is used to use the factory.Įvents defined here are called domain events and are issued when domain logic is executed, and domain events are received by domain event handlers in the application layer and execute logic according to the event. In addition, with a separated interface pattern, the interface of the repository exists in the domain layer and the implementation is in the infrastructure layer. The repository basically manages a collection of domain objects. In addition, domain events generated by business logic execution and the repository interface of the domain model are defined here. Here, a model consisting of aggregate, entity, and vo is implemented, and the model has core business logic inside. The domain layer is the core layer in domain-driven design and the highest level layer that does not depend on any layer. It also briefly summarizes how CQRS is implemented with domain driven design and how event driven appears in this configuration. The domain-driven design consists of four layers, each consisting of interface, application, domain, and infrastructure.Įach layer depends on a different layer, and we want to start with the most important layer, the domain layer. This repository presents examples of applications using domain-driven design and CQRS using nest, a nodejs framework using typescript. Showing how you can implement application for microservice architectureĭomain Driven Design and CQRS can be used to design individual services in msa.