CODEWITHSUNDEEP
javascriptionic-frameworkionic2
Gutto Freitas
Gutto Freitas

Reputation: 33

Manually throw error ionic 2

I am communicating with a webservice and the return can be negative or porisitvo and will fall into the success of the call, but if the return is negative I need to manually throw an exception

 .map(res => res.json())
  .subscribe(res => {
    let returno = JSON.parse(res.d);  
    if (returno.status == 'success') {
      this._loggedIn(returno);
    } else {
      throw returno;
    }
  }, err => {
    console.error('ERROR', err);
  });

Upvotes: 2

Views: 1744

Answers (2)

keldar
keldar

Reputation: 6252

I expect you'll want all of your subscribers to handle the error in the same way? Therefore, you can handle the error at the Observable level, not the Subscriber level.

Thus, you can do something like the following:

public tryLogin(url: string): Observable<any> {
  return this.http.get(url)
    .map(res => res.json().d)
    .map(res => {
      if (res.status !== 'success') {
        Observable.throw(res);
      }

      return res;
    });
}

Then you can call this code in the following fashion:

this.tryLogin('mydata')
  .subscribe(
    data => this._loggedIn(data),
    err => console.log(err);
  )

The great thing with this approach is, if you don't want your subscribers to know what's gone on, you can abstract that and either authenticate them in the next callback, or handle the event of a failure in the error callback.

Upvotes: 0

Stan
Stan

Reputation: 26511

You can throw exceptions in JS by just passing objects to throw. So throw err in your case.

Upvotes: 1

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