rxjs 中基于 boolean observable 的条件 observable 转换

Question

我如何根据布尔 Observable 编辑我的 Observable 值，只要这个布尔 Observable 发生变化，$ships Observable 就会被转换。

areShipsExpanded$: Observable<boolean>;
ships$: Observable<Ship>;

this.ships$ = this.shipsDataSource.getData().pipe(
    map(s => {
          if(this.areShipsExpanded$) {
              // do something with s
          } else {
              // do something else with s
          }
    return s;
})

当然会在视图中使用 ships$ | async

以上代码不正确，因为当 this.areShipsExpanded$ 发生变化时 Observable 不会再次转换。

Answer 1

areShipsExpanded$: Observable<boolean>;
ships$: Observable<Ship>;

this.ships$ = this.shipsDataSource.getData().pipe(
combineLatest(this.areShipsExpanded$),
map(([ships, expanded]) => {
      if(expanded) {
          // do something with ships
      } else {
          // do something else with ships
      }
return ships;
})

rxjs 中基于 boolean observable 的条件 observable 转换

Conditional observable transformation based on boolean observable in rxjs

rxjs

angular

rxjs6