Need Help Accessing Variable From Service In Angular 2

Passing the URL id from the last page a user was on to a service that I can reference in a dialog. issuer.service.ts Page that has the URL id I want (dashboard.component.ts) Comp

Solution 1:

you can see this example, and It's modified list:

• use queryPamas to get query string, not params (DashboardComponent)

• use ReplaySubject(1) to return the last urlId; it's don't have a default value, just return prev one value (IssuerService)

• get observable from getUrlid and subscribe it in components that want to show url id

export class IssuerService {


  private urlidSource = new ReplaySubject<string>(1);

  constructor() {
  }

  changeUrlid(urlid: string) {
    this.urlidSource.next(urlid);
  }

  getUrlid() {
    return this.urlidSource;
  }

}

export class DashboardComponent implements OnInit {

  urlid: string;
  constructor(
    // private route: ActivatedRoute,
    private router: Router,
    private issuerService: IssuerService,
    // public dialog: MatDialog
  ) { }

  newUrlid() {
    // Get URL ID
    this.route.queryParams.subscribe((queryParam) => {
      const id = queryParam['id'];
      if (!id) {
        return;
      }
      this.issuerService.changeUrlid(id);
    });
  }

  ngOnInit() {
    this.newUrlid();

    this.issuerService.getUrlid().subscribe(urlid => {
      this.urlid = urlid;
    });
  }

}

export class HelloComponent implements OnInit {
  urlid;
  constructor(
    private issuerService: IssuerService
  ) { }

  ngOnInit() {
    this.issuerService.getUrlid().subscribe(urlid => {
      this.urlid = urlid;
    });
  }
}

Solution 2:

You do not need a parameter for your get Method since you already have the value inside the service,

  getUrlid() {
    return this.currentUrlid;
  }

and you can use retrieve the value in the 2nd component as follows,

this.issuerService.currentUrlid.subscribe((value: string) => {
         this.urlid = value;
}