Use switch
:
Transforms an observable sequence of observable sequences into an observable sequence producing values only from the most recent observable sequence.
Example 1
var obsNumber,
obsText1,
obsText2;
obsNumber = Rx.Observable.interval(500).take(10);
obsText1 = Rx.Observable.return('a');
obsText2 = Rx.Observable.return('b');
obsNumber
.do(function (x) {
console.log('x: ' + x);
})
.map(function (x) {
return x < 5 ? obsText1 : obsText2;
})
.switch()
.subscribe(function (context) {
console.log('context: ' + context);
});
<script src='https://rawgit.com/Reactive-Extensions/RxJS/v.2.5.3/dist/rx.all.js'></script>
Example 2
var obsNumber,
arrOfObservables;
obsNumber = Rx.Observable.range(0, 3);
arrOfObservables = [
Rx.Observable.return('a'),
Rx.Observable.return('b'),
Rx.Observable.return('c')
];
obsNumber
.do(function (x) {
console.log('x: ' + x);
})
.map(function (x) {
return arrOfObservables[x];
})
.switch()
.subscribe(function (context) {
console.log('context: ' + context);
});
<script src='https://rawgit.com/Reactive-Extensions/RxJS/v.2.5.3/dist/rx.all.js'></script>