[RxJS] ReplaySubject with buffer

It is not good to cache all the value by using ReplaySubject, so we need to add cache logic for this.

The first parameter to the constructor of ReplaySubject takes a number that represents how many values we want to buffer:

var subject = new Rx.ReplaySubject(2); // Buffer size of 2
  subject.onNext(1);
  subject.onNext(2);
  subject.onNext(3);
subject.subscribe(function(n) {
  console.log(‘Received value:‘, n);
});

/*
"Received value:"
3
"Received value:"
2
*/

The second parameter takes a number that represents the time in miliseconds during which we want to buffer values:

var subject = new Rx.ReplaySubject(null, 200); // Buffer size of 200ms
  setTimeout(function() { subject.onNext(1); }, 100);  //100+200 < 300
  setTimeout(function() { subject.onNext(2); }, 200);  //200+200 > 350
  setTimeout(function() { subject.onNext(3); }, 300);  //300+200 > 350
  setTimeout(function() {
subject.subscribe(function(n) {
  console.log(‘Received value:‘, n);
});
subject.onNext(4);
}, 350);

/*
"Received value:"
2
"Received value:"
3
"Received value:"
4
*/