CanActivateChild

Interface that a class can implement to be a guard deciding if a child route can be activated. If all guards return true, navigation continues. If any guard returns false, navigation is cancelled. If any guard returns a UrlTree, current navigation is cancelled and a new navigation begins to the UrlTree returned from the guard.

The following example implements a CanActivateChild function that checks whether the current user has permission to activate the requested child route.

class UserToken {}
class Permissions {
  canActivate(user: UserToken, id: string): boolean {
    return true;
  }
}

@Injectable()
class CanActivateTeam implements CanActivateChild {
  constructor(private permissions: Permissions, private currentUser: UserToken) {}

  canActivateChild(
    route: ActivatedRouteSnapshot,
    state: RouterStateSnapshot
  ): MaybeAsync<GuardResult> {
    return this.permissions.canActivate(this.currentUser, route.params.id);
  }
}

Here, the defined guard function is provided as part of the Route object in the router configuration:

@NgModule({
  imports: [
    RouterModule.forRoot([
      {
        path: 'root',
        canActivateChild: [CanActivateTeam],
        children: [
          {
             path: 'team/:id',
             component: TeamComponent
          }
        ]
      }
    ])
  ],
  providers: [CanActivateTeam, UserToken, Permissions]
})
class AppModule {}