仅显示Object.keys的前几个元素

Question

I have made a JSON Request so i can bring the Objects in Angular2. But I want to display only the first 15 elements and then if it works repeat the same process on InfiniteScroll. So this is one of my code.

  setList(informes) {
  if (informes) {
     for (let id of Object.keys(informes)){
         this.count = 0;
         for (let i = 0; i < 15; i++) {
            let node = informes[id];
            this.informes.push(node[this.count]);
            console.log (id);
            this.count++;
          }
      }
   }
}

Obviously It doesn't work, it keeps giving me all elements like 15 times each. I know that but on the other hand if i make the opposite.

setList(informes) {
  if (informes) {
     for (let i = 0; i < 15; i++) {
        for (let id of Object.keys(informes)){
        let node = informes[id];
        this.informes.push(node[this.count]);
        console.log (id);
        }
        this.count++
      }
   }
}

It counts the number of nodes in total.

What i want is to display only the first 15 elements. And then repeat the code in my other function infiniteScroll (I will do that by myself, it works).

Any suggestion will be appreciated.

UPDATE:

Here's the constructor:

 constructor(public navCtrl: NavController, public navParams: NavParams, public nav: NavController, public http: Http, public sanitizer: DomSanitizer) {
    this.dataUrl = 'https://myurl.com/ionic/'; //example
    if (this.dataUrl) {
         this.http.get(this.dataUrl)
            .map(res => res.json())
            .subscribe(informes => this.setList(informes));
         }
    }

UPDATE 2:

The code works well. I had to modify some things to make it work. I will update the script so if it could help someone.

    setList(informes) {
  if (informes) {
     let ids = Object.keys(informes);
        ids.forEach((id, index) => {
           if(index < 15){
               let node = informes[id];
               this.informes.push(node);
               this.count++;
               console.log(this.count);
           }
      });
   }
}

goToNodeInformes(node){
   this.navCtrl.push(NodeInformesPage, {'node':node.nid});
}

doInfinite(infiniteScroll, informes) {
    informes = this.informes;
    setTimeout(() => {
      let ids = Object.keys(informes);
        ids.forEach((id, index) => {
           if(index < 15){
               let node = informes[id];
               this.informes.push(node);
               this.count++;
               console.log(this.count);
           }
      });
      infiniteScroll.complete();
    }, 500);
  }

}

I will figure what i have to do for not repeating the same nodes (will update) but the counter works!!!

Answer 1

I think you are looking for something like this :

let keys = Object.keys(informes);

keys.foreach((key, index) => {
   if(index < 15){
       let node = informes[key];
       this.informes.push(node);
       console.log(informes[key]);
   }
});