angularrxjsobservablerxjs5rxjs-dom

Rx.Observable.Of error is not catched

i want to return token from localStorage and catch error. 

Observable.of(JSON.parse(localStorage.getItem('currentUser')).token)
.catch((er) => Observable.of(console.log(er))

But it does not catch it. Interesting is when I use try catch method ,I can catch error

  try {
      return Observable.of(JSON.parse(localStorage.getItem('currentUser')).token);
    } catch (er) {
      console.log(er);
    }

What is the reason of that? Hope someone give advice.enter image description here Thanks

Solution

  • Because the error is thrown before it's result is passed into Observable.of. This is unrelated to RxJS, that's how the order of statements is executed by the JS interpreter.

    You can do for example:

    Observable.defer(() => Observable.of(JSON.parse(localStorage.getItem('currentUser')).token))
  .catch(???) // returning Observable.of(console.log(er) is probably useless