angular2
Version:
Angular 2 - a web framework for modern web apps
69 lines • 2.16 kB
JavaScript
import { stringify, isBlank } from 'angular2/src/facade/lang';
import { BaseException } from 'angular2/src/facade/exceptions';
import { TypeLiteral } from './type_literal';
import { resolveForwardRef } from './forward_ref';
export { TypeLiteral } from './type_literal';
/**
* A unique object used for retrieving items from the {@link Injector}.
*
* Keys have:
* - a system-wide unique `id`.
* - a `token`.
*
* `Key` is used internally by {@link Injector} because its system-wide unique `id` allows the
* injector to store created objects in a more efficient way.
*
* `Key` should not be created directly. {@link Injector} creates keys automatically when resolving
* providers.
*/
export class Key {
/**
* Private
*/
constructor(token, id) {
this.token = token;
this.id = id;
if (isBlank(token)) {
throw new BaseException('Token must be defined!');
}
}
/**
* Returns a stringified token.
*/
get displayName() { return stringify(this.token); }
/**
* Retrieves a `Key` for a token.
*/
static get(token) { return _globalKeyRegistry.get(resolveForwardRef(token)); }
/**
* @returns the number of keys registered in the system.
*/
static get numberOfKeys() { return _globalKeyRegistry.numberOfKeys; }
}
/**
* @internal
*/
export class KeyRegistry {
constructor() {
this._allKeys = new Map();
}
get(token) {
if (token instanceof Key)
return token;
// TODO: workaround for https://github.com/Microsoft/TypeScript/issues/3123
var theToken = token;
if (token instanceof TypeLiteral) {
theToken = token.type;
}
token = theToken;
if (this._allKeys.has(token)) {
return this._allKeys.get(token);
}
var newKey = new Key(token, Key.numberOfKeys);
this._allKeys.set(token, newKey);
return newKey;
}
get numberOfKeys() { return this._allKeys.size; }
}
var _globalKeyRegistry = new KeyRegistry();
//# sourceMappingURL=key.js.map