在 Angular2 中共享一个 observable/subject

Sharing an observable/subject in Angular2

编辑:就其价值而言,我了解到 SharedService 被初始化了两次。我怀疑我正在处理单独的实例,这就是 .subscribe() 仅限于发起者的原因。我不知道如何纠正这个...我以为 Angular2 中的一切都是单例?

我有两个组成部分。我希望任一组件都能够通过服务 POST,并让两个组件都收到响应。

对于这个问题的演示,这两个组件非常基本并且本质上相同。这里没什么可看的,但它们只是为了以防万一:

Foo 组件

@Component({
    selector: "foo",
    providers: [SharedService]
})

export class FooComponent {
    constructor(private _api:API, private _service:SharedService) {
        this._service.data$.subscribe(
            response => console.log("FOO!", response)
            // error not required here since the service handles it for all dependents.
        );
    }

    doSomething(values) {
        this._service.post(values);
    }
}

条形组件

@Component({
    selector: "bar"
})

export class BarComponent {
    constructor(private _api:API, private _service:SharedService) {
        this._service.data$.subscribe(
            response => console.log("BAR!", response)
            // error not required here since the service handles it for all dependents.
        );
    }

    doSomething(values) {
        this._service.post(values);
    }
}

SharedService 是我一直努力解决问题的地方。

@Injectable()
export class SharedService {
    private _observer: Observer<Response>;
    public data$;

    // i wrapped Http in an API service.  it does the following:
    // 1.  convenience methods like .map() for the observables
    // 2.  adding headers to every request so that i don't need to do that for every service
    // 3.  takes the first parameter e.g. "login" and converts it to a full endpoint
    // 4.  converts the "values" object in to a body string

    constructor(private _api: API) {
        this.data$ = new Observerable(observer = this._observer = observer).share();
    }

    post(values:IValues) {
        this._api.post("foobar", values).subscribe(
            response => this._observer.next(response),
            error => console.log("foobar failure", error);
        );
    }
}

无论我尝试什么,我都只得到调用组件的成功条件。因此,如果我从 "Foo" 触发服务,我会得到 "FOO!",如果我从 "Bar" 调用它,我会得到 "BAR!".

理想情况下,我可以从 "Foo" 调用它并接收回 "FOO!" 和 "BAR!"。这些响应的顺序并不重要。

问题是我有这个但没有意识到:

@Component({
    selector: "foo",
    providers: [SharedService] // only existed on one of them
})

@Component({
    selector: "bar"
})

其中创建了两个实例。工作代码只是:

@Component({
    selector: "foo"
})

@Component({
    selector: "bar"
})