CODEWITHSUNDEEP
angulartypescriptobservable
Mr.wiseguy
Mr.wiseguy

Reputation: 4252

Return value in Catch Angular HttpClient

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

Upvotes: 0

Views: 1773

Answers (2)

boukobba adil
boukobba adil

Reputation: 150

return Observable.of(new MapConfiguration());

to generate an error with your object as a message

return Observable.throw(new MapConfiguration());

Upvotes: 0

Sonicd300
Sonicd300

Reputation: 2049

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

Upvotes: 3

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