Configurations

Configuration is a class that is annotated with @Configuration or @ClawjectApplication. These decorators provide metadata to the container to process the configuration class and generate the corresponding metadata.

Each application has at least one configuration, a class that is annotated with @ClawjectApplication. The root configuration class is the entry point Clawject uses to resolve beans and its dependencies, imported configurations and exposed beans.

Each application can have as many configurations as needed, and each configuration can import other configurations. All the configurations are singletons in the context of the application.

tip

Configuration classes allow encapsulating specific beans, or vice versa, to expose beans and configuration imports to the container using @Internal and @External decorators.

Configuration class abilities

Each class that is annotated with @Configuration or @ClawjectApplication is a configuration class.

Configuration classes allow you to:

• Define beans
• Import configurations
• Define lifecycle methods
• Export beans and re-export configuration imports to the container

Features configuration

The PetRepository, CatService and DogService belong to the same feature. Cat and Dog services are both using PetRepository to acquire the data. As they are part of one domain, it makes sense to define beans for them in a single feature-specific configuration class.

pet-configuration.ts

import { Bean, Configuration } from '@clawject/di';
import { CatService } from './cat-service';
import { DogService } from './dog-service';
import { PetRepository } from './pet-repository';

@Configuration
export class PetConfiguration {
  catService = Bean(CatService);
  dogService = Bean(DogService);
  petRepository = Bean(PetRepository);
}

Above, we defined the PetConfiguration in the pet-configuration.ts file. The last thing we need to do is import this configuration into the root application class.

application.ts

import { ClawjectApplication, Import } from '@clawject/di';
import { PetConfiguration } from './pet-configuration';

@ClawjectApplication
export class Application {
  petConfiguration = Import(PetConfiguration);
}