提供了编程的基础技术教程

zl程序教程

您现在的位置是：首页 >  其它

当前栏目

[RxJS] Implement pause and resume feature correctly through RxJS

and Rxjs Feature Through Implement
2023-09-14 09:00:51 时间

Eventually you will feel the need for pausing the observation of an Observable and resuming it later. In this lesson we will learn about use cases where pausing is possible, and what to do when pausing is impossible.

 

const resume$ = new Rx.Subject();

const res$ = resume$
  .switchMap(resume =>
    resume ?
      Rx.Observable.interval(2000) :
      Rx.Observable.empty()
  )
  .do(x => console.log('request it! ' + x))
  .switchMap(ev => Rx.Observable.ajax({
    url: 'https://jsonplaceholder.typicode.com/users/1',
    method: 'GET',
  }));

res$.subscribe(function (data) {
  console.log(data.response);
});

resume$.next(false);
setTimeout(() => resume$.next(true), 500);
setTimeout(() => resume$.next(false), 5000);

 

here use 

Rx.Observable.empty()

inside switchMap(), it means if code goes to empty(), then the rest of code:

 .do().switchMap()

won't run.

 

If just subscribe, it trigger complete function:

var source = Rx.Observable.empty();

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
    console.log('Completed');
  });
  
// => Completed

 

相关文章