Leveraging merge with lettable operators

I am currently facing an issue with mapping an array of items to observables and then combining them using the merge operator. My goal is to achieve this using lettable operators. Here's an example of what I've been attempting:

// obs is an array of observables
from(obs).pipe(merge());

However, when I subscribe to this setup, it simply emits an array of observables right away instead of emitting the merged observable values.

I have experimented with the following approach:

from(obs).pipe(mergeMap(ob => ob));

Surprisingly, this method works as intended. But I expected that using .merge would produce the same outcome. Is there a way for me to flatten the observable by utilizing merge?

typescriptrxjs

Answer №1

I realized that I needed to implement the mergeAll operator instead of using merge.

from(obs).pipe(mergeAll());

Unlike the .merge operator which simply chains the emission of an observable, mergeAll allows for handling an arbitrary number of input observables without any transformation. In my initial query, there was no actual processing being done, essentially mirroring just using from(obs).

If you have two Observables, you could also use obs[0].pipe(merge(obs[1])) or continue chaining them together. The benefit of mergeAll is its flexibility in handling multiple input observables compared to the static merge operator.

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