RxJS: MergeMap with Preserving Input order

Question

Requirement:

urls = [url1, url2, url3]

Fire all 3 urls parallely and paint the Dom in the sequnce of the urls list

 ex: Fini         


        

Answer 1

You can form a sequence with fetch and paint then forkJoin/Promise.all them

p1 = fetch(url1)
p2 = fetch(url2)
p3 = fetch(url3)

forkJoin(
from(p1).pipe(tap(_=>paint dom...))
from(p1).pipe(tap(_=>paint dom...))
from(p1).pipe(tap(_=>paint dom...))
).subscribe()