CODEWITHSUNDEEP
angularrxjs
Vahid
Vahid

Reputation: 7561

What is SwitchMap in RxJS

I'm using Restangular in my Angular 5 project. In addErrorInterceptor section, if you look at the code it calls the refreshAccesstoken method and then gets the new access token in switchMap part. By now I'm returning a replySubject in my refreshAccesstoken method so if I subscribe to the return value, I can get the new access token but I'm not able to get it in switchMap as I don't know what it is (I've also searched for switchMap but I just found some functions which didn't help me).

Here is my code for AuthService.refreshAccessToken:

refreshAccessToken() {
  let resultSubject: ReplaySubject<any> = new ReplaySubject<any>();
  const url = this.AUTH_URL + 'oauth/token';
  const requestOptions = {
    headers: new Headers({
      authorization: 'Basic ' + btoa(this.clientId + ':' + this.clientSecret),
      'Content-Type': 'application/x-www-form-urlencoded'
    })
  };
  const body = {
    grant_type: 'refresh_token',
    refresh_token: this.refreshToken,
    // scope: ''
  };
  let params = this.utilityService.convertObjectToURLParams(body);

  this._http.post(url, params.toString(), requestOptions).subscribe(
    response => {
      let result = response.json();
      // console.log('refreshed_access_token', result);
      this.accessToken = result.access_token
      this.refreshToken = result.refresh_token
      this.expireIn = result.expire_in
      resultSubject.next(this.accessToken);
    },
    error => {
      resultSubject.error(error);
    }
  );
  return resultSubject;
}

Upvotes: 0

Views: 289

Answers (1)

Picci
Picci

Reputation: 17762

Why do you need to use a ReplySubject? It seems you are using it just to emit the new access token.

If this is the case, and if I do not miss something, then you could reach the same result in a simpler way, like 

refreshAccessToken() {
  const url = this.AUTH_URL + 'oauth/token';
  const requestOptions = {
    headers: new Headers({
      authorization: 'Basic ' + btoa(this.clientId + ':' + this.clientSecret),
      'Content-Type': 'application/x-www-form-urlencoded'
    })
  };
  const body = {
    grant_type: 'refresh_token',
    refresh_token: this.refreshToken,
    // scope: ''
  };
  let params = this.utilityService.convertObjectToURLParams(body);

  this._http.post(url, params.toString(), requestOptions).map(
    response => {
      let result = response.json();
      // console.log('refreshed_access_token', result);
      this.accessToken = result.access_token
      this.refreshToken = result.refresh_token
      this.expireIn = result.expire_in
      return this.accessToken;
    }
  );
}

Basically you just substitute subscribe with map and then it should work

Upvotes: 2

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