Get angular Observable stream as array

问题

I have list, that should simulate the stream :

list = [
  {name : 'Str1', age: 10},
  {name : 'Str2', age: 10},
  {name : 'Str3', age: 10}
];

and I've created an Observable from this list:

Observable.from(this.list).skip(this.currentPage * this.pageSize).take(this.pageSize).subscribe(data => this.pagerList = data, console.error);

And in the subscribe method I get the values one by one. How I'm supposed to wait for the whole data to be returned and then to get the whole list. There is take() operator, and after it the Observable have to stop.

I don't want to put every value one by one in the array.

I'm new here, not only for angular, but for javascript as well.

回答1:

Have you tried to use toArray operator?.

let list = [
  { name: 'Str1', age: 10 },
  { name: 'Str2', age: 10 },
  { name: 'Str3', age: 10 },
  { name: 'Str4', age: 10 },
  { name: 'Str5', age: 10 },
  { name: 'Str6', age: 10 }
];

let currentPage = 2;
let pageSize = 2;

Rx.Observable.from(list)
  .skip(currentPage * pageSize)
  .take(pageSize)
  .toArray()
  .subscribe(data => console.log(data), console.error);

<script src="https://npmcdn.com/@reactivex/rxjs@5.0.3/dist/global/Rx.min.js"></script>

回答2:

The scan operator should do what you want

Observable.from(this.list)
.skip(this.currentPage * this.pageSize)
.take(this.pageSize)
.scan([], acc, curr) => {acc.push(curr); return acc;});
.subscribe(data => this.pagerList = data, console.error);

http://reactivex.io/rxjs/class/es6/Observable.js~Observable.html#instance-method-scan

回答3:

I think this is more appropriate solution:

Observable.of(this.list).map(x => x.slice(this.currentPage * this.pageSize)).map(x => x.slice(0, this.pageSize)).subscribe(data => this.pagerList = data, console.error);

来源：https://stackoverflow.com/questions/42330211/get-angular-observable-stream-as-array

标签

angular

rxjs

observable