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> { canDeactivate(component: T, currentRoute: ActivatedRouteSnapshot, currentState: RouterStateSnapshot, nextState?: RouterStateSnapshot): Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree }
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 ): Observable<boolean|UrlTree>|Promise<boolean|UrlTree>|boolean|UrlTree { 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 {}
You can alternatively provide an in-line function with the canDeactivate
signature:
@NgModule({ imports: [ RouterModule.forRoot([ { path: 'team/:id', component: TeamComponent, canDeactivate: ['canDeactivateTeam'] } ]) ], providers: [ { provide: 'canDeactivateTeam', useValue: (component: TeamComponent, currentRoute: ActivatedRouteSnapshot, currentState: RouterStateSnapshot, nextState: RouterStateSnapshot) => true } ] }) class AppModule {}
canDeactivate() | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
component | T | |
currentRoute | ActivatedRouteSnapshot | |
currentState | RouterStateSnapshot | |
nextState | RouterStateSnapshot | Optional. Default is |
Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree
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Licensed under the Creative Commons Attribution License 4.0.
https://v11.angular.io/api/router/CanDeactivate