每1分鐘回覆一次？

Question

有沒有什麼辦法可以每隔1分鐘回覆一次承諾？ 我試圖這樣的事情，但它一開始只有一次返回承諾：

startWork() { 

    this.dataService.startPing(details).then((result) => { 
     this.timeSlotsRefresh(); 
    }, (err) => { 
     console.log(err); 
    }); 
    } 

然後：

startPing() { 
let startingTime = new Date(); 

return new Promise((resolve, reject) => { 

    let source = Rx.Observable.timer(startingTime, 60000).timeInterval().pluck('interval'); 


    this.Subscription = source 
    .subscribe(data => { 

      this.http.post('http://localhost:63203/api/Ping', JSON.stringify(this.offlinePings[i])) 
      .map(res => res.json()) 
      .subscribe(data => { 
       resolve(data); 
      }, (err) => { 
       reject(err); 
      }); 
    }); 
}); 

}

它基本上告知功能，每1分鐘請致電this.timeSlotsRefresh();刷新數據，我該如何實現？

Answer 1

@Injectable 
 
class Ping { 
 
    readonly observable = Rx.Observable.interval(60000); 
 
    
 
    subscribe(...cbs) { 
 
    return this.observable.subscribe(...cbs); 
 
    } 
 
} 
 

 

 
@Component 
 
class Foo implements OnInit, onDestroy { 
 
    private subscription = null; 
 
    
 
    constructor(private ping: Ping) {} 
 
    
 
    onPing(count) {} 
 
    onPingError(error) {} 
 
    onPingFinish() {} 
 
    
 
    ngOnInit() { 
 
    this.subscription = this.ping.subscribe(
 
     (...d) => this.onPing(...d), 
 
     (...e) => this.onPingError(...e), 
 
     (...f) => this.onPingFinish(...f) 
 
    ); 
 
    } 
 
    
 
    ngOnDestroy() { 
 
    this.subscription.unsubscribe() 
 
    } 
 
}

Promise s的意思是隻有一次工作，你可能需要類似於流媒體的東西，Observable小號可能更適用。

使用rx與interval操作：

var source = Rx 
 
    .Observable 
 
    .interval(2000 /* ms */) 
 
    .map(id => fetch(`https:\/\/jsonplaceholder.typicode.com\/posts\/${id}`).then(res => res.json())) 
 
; 
 

 
var subscription = source 
 
    .subscribe(post => console.log('New Post', post)) 
 
;

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