我想知道是否有一些rxjs操作我可以在forkJoin之后调用以了解我的并行异步任务是否已经完成,所以我可以在angular2模板中使用类似* ngIf =“loaded | async”的东西.
我提出了一个解决方案,但对我来说似乎很麻烦.
我敢打赌,有一种更清洁的rxJS方式.
plunkr如果你需要它：
https://plnkr.co/edit/UFVCJpjKAEGguMls5eIl?p=preview
public loaded:Observable<boolean>;
constructor(private http:Http) {
// This is the best solution I could come up with. Is there a cleaner way
// by just calling some operation after forkJoin instead of building my own observable?
this.loaded = Observable.create((observer) => {
observer.next(false);
Observable.forkJoin(
this.something1(),this.something2(),() => {
// now we know we have finished
observer.next(true);
}
).subscribe();
});
}
something1() {
return this.http.get('test1.json').map((res) => res.json());
}
something2() {
return this.http.get('test2.json').map((res) => res.json());
}
this.loaded = Observable.combineLatest(
this.something1(),() => {
// now we know we have finished
return true
}
);
解决方法
使用combineLatest.这样的事情应该有效：
this.loaded = this.something1().combineLatest(
this.something2(),function (s1,s2) { return true }
).take(1);
还要注意,我最后调用take(1),以确保我们只发出一个事件,因为它只会被加载一次.
