1

我想使用来自多个 api 请求的返回结果并将其作为第二个 api 请求的参数重用，第二个 api 请求返回我必须在第三个 api 请求中重用的结果！

问题是我只能返回一个 api

const email = this.credentialsForm.controls['email'].value;


this.http.get('https://drupal_users/index/' + email).pipe(
        map(users => {
            console.log(users);
            const user = users;
            this.userId = user;
            return user;
        }),
        mergeMap(user => {

           const ObservateurCulture = this.http.get('https://index.php/drupal_users/culture/' + email).subscribe((culture: any) => {})

       // Here i wish to reuse "culture" data in another Api call and reuse result again of "Parcelles" api request
          const Parcelles = this.http.get('https://index.php/drupal_users/totherdata/' + culture);

            return forkJoin([ObservateurCulture, Parcelles]);
        }),
        take(1)
    ).subscribe(result => {
        console.log(result);
        this.loading.dismiss();

    });
4

1 回答 1

0

如果您只想从最后一个 api 获得结果，那么mergeMap对于所有事情来说已经绰绰有余了。

但是，如果您希望将所有 api 中的所有数据结合起来，则必须另外pipe使用map

这是示例片段！

let userId = -1;
const email = 'test';

const getUser = (email) => rxjs.of(1)
const getCulture = (email) => rxjs.of('en-US')
const getData = (culture) => rxjs.of({
  data: {}
})

const getResultFromLastApi = (email) => {
  getUser(email).pipe(
    rxjs.operators.tap(userId => {
      userId = userId;
    }),
    rxjs.operators.mergeMap(userId => getCulture(email)),
    rxjs.operators.mergeMap(culture => getData(culture)),
    rxjs.operators.take(1)
  ).subscribe(result => {
    console.log(result);
  });
}

const getCombinedResult = () => {
  getUser(email).pipe(
    rxjs.operators.tap(userId => {
      userId = userId;
    }),
    rxjs.operators.mergeMap(userId => getCulture(email).pipe(rxjs.operators.map(culture => ({
      userId,
      culture
    })))),
    rxjs.operators.mergeMap(cultureAndUser => getData(cultureAndUser.culture).pipe(rxjs.operators.map(data => ({ ...data,
      ...cultureAndUser
    })))),
    rxjs.operators.take(1)
  ).subscribe(result => {
    console.log(result);
  });
}

getResultFromLastApi(email);
getCombinedResult(email);
<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/6.5.5/rxjs.umd.js"></script>

还

map(users => {
            console.log(users);
            const user = users;
            this.userId = user;
            return user;
        }),

我将使用tap而不是map在本节中，因为您没有转换数据但会在应用程序中造成一些副作用（在应用程序的某处分配 userId）

tap(userId => {
            console.log(userId);
            this.userId = userId;
        }),
于 2020-05-13T11:06:13.070 回答