Reactive Programming with RxJS 5

Handling Errors

Remember when we talked about the three methods we can call on an Observer? (If you need a refresher, refer back to ​The Observer Interface​.) We’re familiar with next and complete, but we haven’t yet used error; it is the key to effectively handling errors in Observable sequences.

To see how it works, we’ll write a simple function to take an array of JSON strings and return an Observable that emits the objects parsed from those strings, using JSON.parse:

import { Observable } from "rxjs";
function getJSON(arr) {
  return Observable.from(arr).map(JSON.parse);
}

We’ll pass an array with three JSON strings to getJSON, in which the second string in the array contains a syntax error, so JSON.parse won’t be able ...