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API

    
      interface FactoryProvider extends FactorySansProvider {}

An injection token. (Typically an instance of Type or InjectionToken, but can be any).

When true, injector returns an array of instances. This is useful to allow multiple providers spread across many files to provide configuration information to a common token.

A function to invoke to create a value for this token. The function is invoked with resolved values of tokens in the deps field.

A list of tokens to be resolved by the injector. The list of values is then used as arguments to the useFactory function.

Usage Notes

const Location = new InjectionToken('location');
        const Hash = new InjectionToken('hash');

        const injector = Injector.create({
          providers: [
            {provide: Location, useValue: 'https://angular.io/#someLocation'},
            {
              provide: Hash,
              useFactory: (location: string) => location.split('#')[1],
              deps: [Location],
            },
          ],
        });

        expect(injector.get(Hash)).toEqual('someLocation');

Dependencies can also be marked as optional:

const Location = new InjectionToken('location');
        const Hash = new InjectionToken('hash');

        const injector = Injector.create({
          providers: [
            {
              provide: Hash,
              useFactory: (location: string) => `Hash for: ${location}`,
              // use a nested array to define metadata for dependencies.
              deps: [[new Optional(), Location]],
            },
          ],
        });

        expect(injector.get(Hash)).toEqual('Hash for: null');

Multi-value example

const locale = new InjectionToken<string[]>('locale');
        const injector = Injector.create({
          providers: [
            {provide: locale, multi: true, useValue: 'en'},
            {provide: locale, multi: true, useValue: 'sk'},
          ],
        });

        const locales: string[] = injector.get(locale);
        expect(locales).toEqual(['en', 'sk']);

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