CanActivateFn

The signature of a function used as a canActivate guard on a Route.

If all guards return true, navigation continues. If any guard returns false, navigation is cancelled. If any guard returns a UrlTree, the current navigation is cancelled and a new navigation begins to the UrlTree returned from the guard.

The following example implements and uses a CanActivateFn that checks whether the current user has permission to activate the requested route.

@Injectable()
class UserToken {}

@Injectable()
class PermissionsService {
  canActivate(currentUser: UserToken, userId: string): boolean {
    return true;
  }
  canMatch(currentUser: UserToken): boolean {
    return true;
  }
}

const canActivateTeam: CanActivateFn = (
  route: ActivatedRouteSnapshot,
  state: RouterStateSnapshot,
) => {
  return inject(PermissionsService).canActivate(inject(UserToken), route.params['id']);
};

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

bootstrapApplication(App, {
   providers: [
     provideRouter([
       {
         path: 'team/:id',
         component: TeamComponent,
         canActivate: [canActivateTeam],
       },
     ]),
   ],
 });