angular2
Version:
Angular 2 - a web framework for modern web apps
30 lines (27 loc) • 849 B
text/typescript
import {CONST} from 'angular2/src/facade/lang';
/**
* Creates a token that can be used in a DI Provider.
*
* ### Example ([live demo](http://plnkr.co/edit/Ys9ezXpj2Mnoy3Uc8KBp?p=preview))
*
* ```typescript
* var t = new OpaqueToken("value");
*
* var injector = Injector.resolveAndCreate([
* provide(t, {useValue: "bindingValue"})
* ]);
*
* expect(injector.get(t)).toEqual("bindingValue");
* ```
*
* Using an `OpaqueToken` is preferable to using strings as tokens because of possible collisions
* caused by multiple providers using the same string as two different tokens.
*
* Using an `OpaqueToken` is preferable to using an `Object` as tokens because it provides better
* error messages.
*/
()
export class OpaqueToken {
constructor(private _desc: string) {}
toString(): string { return `Token ${this._desc}`; }
}