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Aggregate Query Service

The IAggregateQueryService port defines a query interface for reading aggregates and their domain events. It has two primary uses:

  • When a microservice needs to fetch domain events for an external aggregate, either as a fallback to a message broker or to bring its own replicated view up to date when domain events have been missed.
  • When using the dugong CLI.

IAggregateQueryService​

The responsibility of the IAggregateQueryService is to provide a way to expose queries to the outside world through an API. It is used to facilitate inter process communication (IPC) between microservices. Client classes should implement the IAggregateQueryService, while server classes should extend or inject the AggregateQueryService class. They may be implemented like so:

aggregate-query-service.client.ts
import type { IAggregateQueryService } from "@dugongjs/core";

export class AggregateQueryServiceClient implements IAggregateQueryService {
    // Implementation here...
}
aggregate-query-service.server.ts
import { AggregateQueryService } from "@dugongjs/core";

export class AggregateQueryServiceServer extends AggregateQueryService {
    // Implementation here...
}