Creating services in components

In LoopBack 4, a Service class provides access to additional functionality.

• Local services are used to implement “utility” functionality, for example obtain a JWT authentication token for a given user.
• Service proxies are used to access 3rd-party web services (e.g. REST or SOAP), as further explained in Calling other APIs and web services

In an application, a new service is typically created by running lb4 service.

Components can contribute local services as follows.

1. Run lb4 service and choose either Local service class or Local service provider as the service type to create.
2. In your component constructor, create a service binding and add it to the list of bindings contributed by the component to the target application class.

An example showing how to build a component contributing a local service class (MyService) and a local service provider (GeocodeServiceProvider):

import {createServiceBinding} from '@loopback/core';
import {MyService} from './services/my.service.ts';
import {GeocodeServiceProvider} from './services/geocoder.service.ts';

export class SampleComponent implements Component {
  bindings = [
    createServiceBinding(MyService),
    createServiceBinding(GeocoderServiceProvider),
  ];
}