[Library]: Add can exit guard

git-svn-id: https://svn.driver.research-infrastructures.eu/driver/dnet40/modules/uoa-services-library/trunk/ng-openaire-library/src/app@57813 d315682c-612b-4755-9ff5-7f18f6832af3

utils/can-exit.guard.ts

@@ -0,0 +1,22 @@
+import {Observable} from 'rxjs';
+import {Injectable} from '@angular/core';
+import {CanDeactivate} from '@angular/router';
+
+export interface IDeactivateComponent {
+    canExit: () => Observable<boolean> | Promise<boolean> | boolean;
+}
+
+@Injectable({
+    providedIn: 'root'
+})
+export class CanExitGuard implements CanDeactivate<IDeactivateComponent> {
+
+    constructor() {
+    }
+
+    canDeactivate(component: IDeactivateComponent): Observable<boolean> | Promise<boolean> | boolean {
+
+        return component.canExit ? component.canExit() : true;
+    }
+
+}