interface
Configures the Injector
to return an instance of useClass
for a token.
interface StaticClassProvider extends StaticClassSansProvider { provide: any multi?: boolean // inherited from core/StaticClassSansProvider useClass: Type<any> deps: any[] }
Property | Description |
---|---|
provide: any | An injection token. Typically an instance of |
multi?: boolean | 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. |
abstract class Shape { name!: string; } class Square extends Shape { name = 'square'; } const injector = Injector.create([{provide: Shape, useClass: Square, deps: []}]); const shape: Shape = injector.get(Shape); expect(shape.name).toEqual('square'); expect(shape instanceof Square).toBe(true);
Note that following two providers are not equal:
class Greeting { salutation = 'Hello'; } class FormalGreeting extends Greeting { salutation = 'Greetings'; } const injector = Injector.create([ {provide: FormalGreeting, useClass: FormalGreeting, deps: []}, {provide: Greeting, useClass: FormalGreeting, deps: []} ]); // The injector returns different instances. // See: {provide: ?, useExisting: ?} if you want the same instance. expect(injector.get(FormalGreeting)).not.toBe(injector.get(Greeting));
const locale = new InjectionToken<string[]>('locale'); const injector = Injector.create([ {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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https://v10.angular.io/api/core/StaticClassProvider