AsyncSubject of RxJS
Learn about the AsyncSubject of RxJS and its usage in detail.
We'll cover the following...
AsyncSubject emits the last value of a sequence only if the sequence is complete. This value is then cached forever, and any Observer that subscribes after the value has been emitted will receive it right away. The AsyncSubject is convenient for asynchronous operations that return a single value, such as Ajax requests.
Let’s see a simple example of an AsyncSubject subscribing to a range:
const Rx = require('rx');
var delayedRange = Rx.Observable.range(0, 5).delay(1000);
var subject = new Rx.AsyncSubject();
delayedRange.subscribe(subject);
subject.subscribe(
function onNext(item) {
console.log('Value:', item);
},
function onError(err) {
console.log('Error:', err);
},
function onCompleted() {
console.log('Completed.');
}
);
AsyncSubject subscribing to the range operator
In the example given above, delayedRange emits the values 0 to 4 after a delay of one second. Then we create a new AsyncSubject ...
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