@angular/router

CanDeactivate

interface

Interface that a class can implement to be a guard deciding if a route can be deactivated. 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.

  
    interface CanDeactivate<T> {}

Interface that a class can implement to be a guard deciding if a route can be deactivated. 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 CanDeactivate function that checks whether the current user has permission to deactivate the requested route.

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

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

          @Injectable()class CanDeactivateTeam implements CanDeactivate<TeamComponent> {  constructor(private permissions: Permissions, private currentUser: UserToken) {}  canDeactivate(    component: TeamComponent,    currentRoute: ActivatedRouteSnapshot,    currentState: RouterStateSnapshot,    nextState: RouterStateSnapshot  ): MaybeAsync<GuardResult> {    return this.permissions.canDeactivate(this.currentUser, route.params.id);  }}@NgModule({  imports: [    RouterModule.forRoot([      {        path: 'team/:id',        component: TeamComponent,        canDeactivate: [CanDeactivateTeam]      }    ])  ],  providers: [CanDeactivateTeam, UserToken, Permissions]})class AppModule {}

canDeactivate

MaybeAsync<GuardResult>

@paramcomponentT

@paramcurrentRouteActivatedRouteSnapshot

@paramcurrentStateRouterStateSnapshot

@paramnextStateRouterStateSnapshot

@returnsMaybeAsync<GuardResult>