RxJs：$q.when angular2 中的模拟

Question

在AngularJS 1.*中我曾经写过这部分代码，用来刷新auth-token：

...

if (!refreshTokenInProgress) {
  refreshTokenInProgress = AuthService.refreshToken();
}


$q.when(refreshTokenInProgress, function () {
  refreshTokenInProgress = null;

  // re-send requests with error
  ...
}, function () {
  // logout if refresh token rejected

  refreshTokenInProgress = null;

  ...
});

...

如何在 Angular 2 中使用 Observable 翻译这段代码？

我什至不知道，因为这行不通：

if (!refreshTokenInProgress) {
  refreshTokenInProgress = AuthService.refreshToken().subscribe();
}

Observable.forkJoin([this.refreshTokenInProgress]).subscribe(
  success => this.refreshTokenInProgress = null
);

RxJs 中的$q.when 等于什么？

Answer 1

Observable.of(data) 是 $q.when 的模拟

你可以在$Q map to RxJS阅读我关于将 $q 映射到 RxJS 的帖子

这是一个来自真实代码的示例：

spyOn(myService, 'getData').and.returnValue(Observable.of([{id: 1}, {id: 2}]));

或者更复杂一点的：

   deleteRole(role: Role) {
Observable.fromPromise(this.confirmDialogService.open(DELETE_ROLE_TITLE, DELETE_ROLE_CONFIRM_BODY({name: role.name})))
  .switchMap(result => result ? Observable.of(result) : Observable.empty())
  .switchMap(() => this.rolesService.getUsersForRole(role.id))
  .switchMap(({elements: users}) => {
    return _.isEmpty(users) ?
      Observable.of(users) :
      Observable.fromPromise(
        this.confirmDialogService.open(ROLE_IN_USE_TITLE,
          ROLE_IN_USE_CONFIRM_BODY({users: users.map(({firstName, lastName}) => `${firstName} ${lastName}`)}),
          {hideCancelButton: true})
      ).switchMap(() => Observable.empty());
  })
  .switchMap(() => this.rolesService.deleteRole(role))
  .subscribe(data => {
      this.toastr.success(`Role '${role.name}' is deleted`, 'Success');
      this.findallRoles(); //Refresh role grid;
      this.roleDeleted.emit();
    },
    error => {
      this.toastr.error(error, 'Error (rolesService.delete)!', {dismiss: 'click'});
      console.error(error);
    });

}