组件间等待数据服务 Angular，行为主体

Question

I have a Behavior Subject dataService in Angular that makes a request to server to get the user details when admin-layout-component loads (parent component), and then injects the data in the user component, this is my user component onInit:

 ngOnInit(){ this._dataService.currentUserDetails.subscribe(userDetails => this.userDetails = userDetails); console.log(this.userDetails); if(this.userDetails === ''){ this.getUser(); } }

When i refresh the browser in user component, first loads the current component ngOnInit, i have to make the conditional to check userDetails and make a new request to server, but admin-layout-component is making the request too, my question: There is a way to await the dataService so i don't have to make the getUser() twice?. Thanks in advance.

Answer 1

You can use Subject to store information about user and if you need, you always get data from subject by this.userDetails anywhere in you component:

export class Component implements OnInit {
  userDetails$ = new BehaviorSubject<any>(null);

 ngOnInit(){
    this._dataService.currentUserDetails.subscribe(userDetails => {
      this.userDetails.next(userDetails)
    });
 }

 get userDetails(): any {
   return this.userDetails$.getValue();
 }
}

and in template you can subscribe to your service Subject

  <div> {{ userDetails$ | async }} </div>