javascript - 将 observable 数组的 observable 转换为 observable 数组

Question

我正在尝试查询数据库。迭代结果列表，并为每一项再执行一个请求。在 rxjs 构建结束时，我有 Observable<Observable<Timesheet>[]> 。但我需要Observable<Timesheet[]> 。如何做到这一点？

this.caseService.getElapsedCases(date).pipe(
  map(elapsedCases => elapsedCases.map(elapsedCase => {
    return this.caseService.findOneById(elapsedCase.caseId).pipe(
      map(loadedCase => {
        const timesheet: Timesheet = {
          id: elapsedCase.id,
          start: elapsedCase.start,
          end: elapsedCase.end,
          case: loadedCase,
          isActive: false
        };

        return timesheet;
      })
    );
  }))
);

Answer 1

您需要 forkJoin 单独的请求并 mergeMap 到源:

const loadElapsedCase: Observable<TimesheetEnt[]> = getElapsedCase().pipe(
  mergeMap(elapsedCases => elapsedCases.map(elapsedCase => {
    return forkJoin(findOneById().pipe(
      map(loadedCase => {
        return {
          id: elapsedCase.id,
          title: elapsedCase.title,
          case: loadedCase
        };
      }))
    );
  }))
);