RXJS：动态创建的可观察对象中的单个可观察对象

Question

I am trying to create an observable (fixedObservable here) which will be fed by multiple dynamically created observable over time. Whenever a subscription is made than the subscriber should get the most recent value from the fixedObservable. Although I have achieved it but I wanted to know if there is any simple solution to it. You can find the code here https://jsfiddle.net/dzm2t3pa/8/ .

Thanks

 var resultdiv = document.getElementById('result'); function print(message) { var paraEl = document.createElement('p'); paraEl.innerHTML = message; resultdiv.appendChild(paraEl); } var startTime = new Date(); var fixedObservable = new Rx.Subject(); var subscription; function subscribe() { subscription = fixedObservable.subscribe(function(value) { print('subscriber 1:' + value + ' :after ' + (new Date() - startTime) / 1000 + ' secs'); }); } function unsubscribe() { subscription.unsubscribe(); } // Subscribe to the fixedObservable(ie Subject) initiallly subscribe() //Unsubscribe and resubscribe after 11 sec here to see what // happens in that period. //Observation: The values generated in that period are not received as needed. setTimeout(unsubscribe, 11000); setTimeout(subscribe, 22000); //just a simple check with multiple subscribers later.All the //subscribers get the latest value. /*setTimeout(function(){ fixedObservable.subscribe(function(value){ print('subscriber 2:'+value+' :after '+(new Date()-startTime)/1000+' secs'); }); },30000);*/ //setTimeout(function(){},) //Initial Observables which feed the data to fixedObservable var dynamicObservable1 = Rx.Observable.interval(4000); var dynamicObservable2 = Rx.Observable.interval(5000); var counter1 = 0; //subscribe to dynamic observable and pass the data to fixedObservable dynamicObservable1.subscribe(function(value) { counter1 += 1; fixedObservable.next(counter1 + 'th value from 1'); }); var counter2 = 0; dynamicObservable2.subscribe(function(value) { counter2 += 1; fixedObservable.next(counter2 + 'th value from 2'); }); //create a dynamicObservable after 5secs to feed the data and // then destroy it after 2.5 sec ie at 7.5 sec from start. //Observation: 2 value from this stream is received and then stops setTimeout(function() { var counter3 = 0; var dynamicObservable3 = Rx.Observable.interval(1000); var subs = dynamicObservable3.subscribe(function(value) { counter3 += 1; fixedObservable.next(counter3 + 'th value from 3'); }); setTimeout(function() { subs.unsubscribe() }, 2500) }, 5000); setTimeout(function() { unsubscribe(); }, 50000) 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/5.0.1/Rx.min.js"></script> <div id="result"> </div> 

Answer 1

using merge, and no need for a subject i guess. Is something like that ok for you?

const dyn1 = Rx.Observable.interval(300)
                      .timeInterval()
                      .map(interval => {return {value:interval.value, origin:'dyn1'}});
const dyn2 = Rx.Observable.interval(601)
                          .timeInterval()
                          .map(interval => {return {value:interval.value, origin:'dyn2'}});

const m = Rx.Observable.merge(dyn1, dyn2);
m.subscribe(v => console.log(v.value + " from " + v.origin));