I have this in my service

  doSomething(): Observable<any> {
    return this.http.get('')
      .pipe(
        map((data: Response) => {
            if (data && data['success'] && data['success'] === true) {
              return true;
            } else {
              return false;
            }
          }
        )
      );  
  }  

This works, I can subscribe to the function from my ponent, for example

    this.myService.doSomething().subscribe(
        (result) => {
            console.log(result);
        },
        (err) => {
            console.log("ERROR!!!");
        }
    );

Al this already works, but I want to refactor so that I can remove

 if (data && data['success'] && data['success'] === true)

in my map. So that the map function only will be executed when I have upfront did the check. My first thought was to add a function in the pipe stack that will take the Response from the http client, check if the the conditions are good, otherwise throw an error (with throwError function). But I'm struggling how to (well at least figure out which Rxjs function to use).

Can somebody help me out with this?

I have this in my service

  doSomething(): Observable<any> {
    return this.http.get('http://my.api./something')
      .pipe(
        map((data: Response) => {
            if (data && data['success'] && data['success'] === true) {
              return true;
            } else {
              return false;
            }
          }
        )
      );  
  }  

This works, I can subscribe to the function from my ponent, for example

    this.myService.doSomething().subscribe(
        (result) => {
            console.log(result);
        },
        (err) => {
            console.log("ERROR!!!");
        }
    );

Al this already works, but I want to refactor so that I can remove

 if (data && data['success'] && data['success'] === true)

in my map. So that the map function only will be executed when I have upfront did the check. My first thought was to add a function in the pipe stack that will take the Response from the http client, check if the the conditions are good, otherwise throw an error (with throwError function). But I'm struggling how to (well at least figure out which Rxjs function to use).

Can somebody help me out with this?

• javascript
• angular
• rxjs

1 Answer 1

Try using this :

doSomething(): Observable<any> {

    return this.http.get('http://my.api./something')
      .pipe(
        mergeMap((data: Response) => {
            return of(data && data['success'] === true) 
          }
        ));  
}  

You have to perform the mergeMap first to do the check as your observable result will not be available if not...