Middleware

Middleware are services and thus inherits all service properties. Middleware services are then guaranteed to contain two public methods: beforeRequestHandler and afterRequestHandler, which correlates to before and after decorators, respectively. However, both have an empty default implementation and thus one can implement only what's desired.

Create

Middleware can be both scoped or singleton service.

info

Remember to register middleware inside setup in the main project file, i.e

service.registerScopedService(SERVICE.TEST_1_MIDDLEWARE, ExampleMiddlewareService);

class ExampleMiddlewareService extends MiddlewareScopedService {
    @injectService(SERVICE.LOGGER)
    private readonly logger: ILoggerService;

    async beforeRequestHandler(response: Response) {
        this.logger.info(
            `before test-2-middleware running on request: ${this.request.id}`
        );
    }

    async afterRequestHandler(response: Response, result: MediatorResult) {
        this.logger.info(
            `after test-2-middleware running on request: ${this.request.id}`
        );
        return result;
    }
}

Usage

Middleware can be consumed on route handlers via before and after decorators.

If multiple before middleware services are added, they are executed in arbitrary order. If multiple after middleware services are added, they are always executed in the order they were provided.

@httpGet('/:id')
@before(SERVICE.TEST_1_MIDDLEWARE, SERVICE.TEST_2_MIDDLEWARE)
@after(SERVICE.TEST_2_MIDDLEWARE)
public async getUser(@params('id') id: string) {
    return this.mediator.send('GetUserQuery', { id });
}