javascript - Rxjs: Chunk and delay stream?

Question

In short, trying to chunk a really large array into chunks of 10 and wait 5 seconds before emitting the next 10.

Here is what I currently have

Rx.Observable
   .from(hugeArray)
   .bufferCount(10) 
   .delay(5000) //want to wait 5 secs
   .flatMap(e => e) // this needs to go after to flatten the array, buffer spits out arrays of entries
   .flatMap( (data, index) => Rx.Observable.create(observer => {
       // going to render stuff here
       observer.onNext(data)
       observer.onCompleted();  

   }))
   .subscribe(val => console.log('Buffered Values:', val));

Just trying to do 10 chunks ever 5 seconds, only been able to do an initial delay and then it emitted the rest.

Answer 1

Your chain just emitted everything at once and then scheduled each chunk to wait 5s starting at the same time so the delay elapsed for all chunks at the exact same moment.

Solution could be to use concatMap() that subscribes to each Observable one by one.

Rx.Observable
    .from(hugeArray)
    .bufferCount(10)
    .concatMap(data => Rx.Observable.of(data).delay(5000))
    .flatMap(e => e) // or mergeAll() or concatAll()
    .flatMap( (data, index) => Rx.Observable.create(observer => {
        // going to render stuff here
        observer.onNext(data);
        observer.onCompleted();
    }))
    .subscribe(val => console.log('Buffered Values:', val));