CanDeactivate

interface

Contents

Interface that a class can implement to be a guard deciding if a route can be deactivated. If all guards return true, navigation will continue. If any guard returns false, navigation will be cancelled. If any guard returns a UrlTree, current navigation will be cancelled and a new navigation will be kicked off 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
}

Description

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

Methods

canDeactivate()

      
      canDeactivate(component: T, currentRoute: ActivatedRouteSnapshot, currentState: RouterStateSnapshot, nextState?: RouterStateSnapshot): Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree

Parameters

`component`	`T`
`currentRoute`	`ActivatedRouteSnapshot`
`currentState`	`RouterStateSnapshot`
`nextState`	`RouterStateSnapshot`	Optional. Default is `undefined`.

Returns