ANGULAR STREAMLINE PROVIDERS

some-service.providers.ts

// token to access a stream with the organisation information we need
// this is what we inject e.g. @Inject(ORG_INFO) readonly orgInfo$: Observable<string>
export const ORG_INFO = new InjectionToken<Observable<string>>(
    'Organisation name information'
);

// This is what we add to `providers` array in module or component
export const ORGANISATION_PROVIDERS: Provider[] = [
    {
        provide: ORG_INFO,
        deps: [ActivatedRoute, OrgService],
        useFactory: orgFactory,
    },
];

/**
 * @summary extracts org Id from URL and then returns the organisation name
 * */
export function orgFactory(
    { params }: ActivatedRoute,
    orgService: OrgService): Observable<string> {
        return params.pipe(
            switchMap(({orgId}) => {
                return orgService.getOrganisation(orgId)
                    .pipe(
                        map((organisation: Organisation) => organisation.name)
                    );
            })
        );
}