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Inject
decorator
stable
npm Package | @angular/core |
---|---|
Module | import { Inject } from '@angular/core'; |
Source | core/src/di/metadata.ts |
Metadata Overview
@Inject({
token: any
})
How To Use
@Injectable()
class Car {
constructor(@Inject("MyEngine") public engine:Engine) {}
}
Description
For more details, see the "Dependency Injection Guide".
Example
class Engine {}
@Injectable()
class Car {
constructor(@Inject('MyEngine') public engine: Engine) {}
}
const injector =
ReflectiveInjector.resolveAndCreate([{provide: 'MyEngine', useClass: Engine}, Car]);
expect(injector.get(Car).engine instanceof Engine).toBe(true);
When @Inject()
is not present, Injector
will use the type annotation of the parameter.
Example
class Engine {}
@Injectable()
class Car {
constructor(public engine: Engine) {
} // same as constructor(@Inject(Engine) engine:Engine)
}
const injector = ReflectiveInjector.resolveAndCreate([Engine, Car]);
expect(injector.get(Car).engine instanceof Engine).toBe(true);
Metadata Properties
© 2010–2018 Google, Inc.
Licensed under the Creative Commons Attribution License 4.0.
https://v5.angular.io/api/core/Inject