Class Overview
class InjectionToken extends OpaqueToken {}
Class Description
Creates a token that can be used in a DI Provider.
Use an InjectionToken whenever the type you are injecting is not reified (does not have a
runtime representation) such as when injecting an interface, callable type, array or
parametrized type.
InjectionToken is parametrize on T which is the type of object which will be returned by the
Injector. This provides additional level of type safety.
interface MyInterface {...}
var myInterface = injector.get(new InjectionToken<MyInterface>('SomeToken'));
// myInterface is inferred to be MyInterface.
Example
const injector: Injector =
ReflectiveInjector.resolveAndCreate([{provide: 'validToken', useValue: 'Value'}]);
expect(injector.get('validToken')).toEqual('Value');
expect(() => injector.get('invalidToken')).toThrowError();
expect(injector.get('invalidToken', 'notFound')).toEqual('notFound');
Constructor
constructor(desc: string)
exported from core/index,
defined in core/src/di/injection_token.ts