Return value in Catch Angular HttpClient

Question

I am trying to create a generic service to fetch some settings from the server. When an error occurs I would like to catch this error and return a default value (locally I have a default configuration that should be used when an error occurs).

Since I am using Angular 4.3.6 I can use the new HttpClientModule.

The code:

/**
  * Fetches the map settings
  * @returns { Observable<MapConfiguration> }
  */

public getMapConfiguration(): Observable<MapConfiguration> {
  return this.http.get<MapConfiguration>(MapService.MAPSETTINGSURL)
    .catch((exception) => {
      console.warn('Could not fetch map configuration due to: ', exception);
      return new MapConfiguration();
    });
}

This code gives the following error:

Type 'MapConfiguration' is not assignable to type 'ObservableInput<{}>'.

I am new to Observables (used to promises) and with a promise I could return a value in the catch. How can I solve this problem, so that there is always a value returned?

I would like to make the service handle the error and not the subscriber

Sonicd300 · Accepted Answer · 2017-09-18 16:33:00Z

3

In order to have always a returning value you can wrap it as observable by using return Observable.of(new MapConfiguration()); in your catch.

answered Sep 18, 2017 at 16:33

Sonicd300

2,0591 gold badge18 silver badges23 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

boukobba adil · Accepted Answer · 2017-09-18 16:38:12Z

0

return Observable.of(new MapConfiguration());

to generate an error with your object as a message

return Observable.throw(new MapConfiguration());

answered Sep 18, 2017 at 16:38

boukobba adil

1409 bronze badges

Collectives™ on Stack Overflow

Return value in Catch Angular HttpClient

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related