What are some advanced RxJS operators I should know?

What are some advanced RxJS operators I should know?

Some advanced RxJS operators include switchMap, mergeMap, concatMap, and combineLatest. Would you like to know how to use any of these?

Yes, can you explain switchMap with an example?

Sure! switchMap is used to switch to a new observable when a new value is emitted. For example, if you have a search input, switchMap can be used to cancel the previous search request when the user types a new query.

That sounds useful! How does it handle multiple emissions?

switchMap will unsubscribe from the previous observable and only emit values from the latest one. This is great for scenarios like live search, where you only want the most recent result.

Can you give me a code snippet for that?

Certainly! Here's a simple example:

import { fromEvent } from 'rxjs';
import { switchMap, debounceTime } from 'rxjs/operators';

const searchInput = document.getElementById('search');

fromEvent(searchInput, 'input')
  .pipe(
    debounceTime(300),
    switchMap(event => searchApi(event.target.value))
  )
  .subscribe(results => console.log(results));

This code listens for input events, debounces them, and uses switchMap to fetch search results.