Angular routing with query parameters

Question

I'm currently building on Angular: 7.2.14 and wanted to see if someone could explain how to redirect query parameters either with a route guard, shared service or other means etc.

The problem I'm trying to solve requires query parameters to come in from the root Uri path then redirect the route to the correct child component keeping the query intact when the router changes Uris.

For example, say you had an outside href linked into an angular app (see routes below) and the original route href is: domain.com?foo=bar, since this is the root route of '' angular will then transfer the route over to the matching child route '' this in turn redirects to 'login'. The end result lands you here domain.com/#/login and my query of ?foo=bar is lost.

How do you create a route, route-guard or even a service etc. and maintain the original query but also redirecting you to the final location of domain.com/#/login?foo=bar starting from the root path?

const routes: Routes = [
  {
  path: '', component: AuthorizeComponent,
  children: [
    { path: '', redirectTo: 'login'  },
    { path: 'login', component: LoginComponent, canActivate: [LoginGuardService] },
    { path: 'confirm', component: ConfirmComponent, canActivate: [ConfirmGuardService] },
    { path: 'error', component: ErrorComponent },
  ]
}];

I will try to show my setup here. I do have a LoginGuardService which implements canActivate and within the canActivate function I can redirect keeping the query together by using router.navigate(['/login'], { queryParams: route.queryParams }), except this ONLY works when you link directly to the route like domain.com/#/login?foo=bar not to the root first.

LoginGuardService

canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {

    if (this.auth.isLoggedIn()) {
      this.router.navigate(['/confirm'], { queryParams: route.queryParams });
   } else {
      return true;
   }

}

ConfirmGuardService

 canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {

   if (!this.auth.isLoggedIn()) {
     this.router.navigate(['/login'], { queryParams: route.queryParams });
   } else {
     return true;
   }

 }

Solution

Set queryParamsHandling: 'preserve' in your navigation extras (Resource):

this.router.navigate(['/confirm'], { queryParamsHandling: 'preserve' });