# Country State Service

This provides a service for other components to use to retrieve country and state information.

## Requirements

The Country State Service interface:

```typescript
export interface CountryStateServiceInterface {
  getCountriesOptions(): Observable<Country[]>;
  getStatesOptions(countryCode: string): Observable<State[]>;
}
```

To implement the interface make a new service that implements the interface:

```typescript
…
import {CountryStateServiceInterface, Country, State} from '@vendasta/country-state-service';

@Injectable()
export class CountryStateService implements CountryStateServiceInterface {
  …
  getCountriesOptions(): Observable<Country[]> {
    // Implement how the project will return the list of countries
  }
  getStatesOptions(countryCode: string): Observable<State[]> {
    // Implement how the project will return the list of states for the country
  }
}
```

Next you will need to provide your service as that interface (generally in `app.module.ts`)

```typescript
import { CountryStateService } from './country-state.service';
import { CountryStateServiceInterfaceToken } from '@vendasta/country-state-service';
…
@NgModule({
  …
  providers: [
    CountryStateService, {provide: CountryStateServiceInterfaceToken, useExisting: CountryStateService}
  ],
})
```

* Note: To be able to inject an interface, you will have to provide the InjectionToken and not the interface itself (`CountryStateServiceInterfaceToken` vs `CountryStateServiceInterface`).