Add block navigation guards

src/app/guards/navigation-blocked/navigation-blocked.guard.spec.ts

@@ -0,0 +1,71 @@
+import { Component } from '@angular/core';
+import { TestBed, async, ComponentFixture, inject } from '@angular/core/testing';
+import { Observable } from 'rxjs';
+import { AlertController } from '@ionic/angular';
+
+import { NavigationBlockedGuard, HasNavigationBlocked } from './navigation-blocked.guard';
+
+@Component({
+  template: '<div></div>'
+})
+class HasNavigationBlockedMockComponent implements HasNavigationBlocked {
+  hasNavigationBlockedValue: Observable<boolean> | Promise<boolean> | boolean;
+
+  hasNavigationBlocked(): Observable<boolean> | Promise<boolean> | boolean {
+    return this.hasNavigationBlockedValue;
+  }
+}
+
+describe('NavigationBlockedGuard', () => {
+  let component: HasNavigationBlockedMockComponent;
+  let fixture: ComponentFixture<HasNavigationBlockedMockComponent>;
+  let guard: NavigationBlockedGuard;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({
+      imports: [],
+      declarations: [ HasNavigationBlockedMockComponent ],
+      schemas: [],
+      providers: [],
+    })
+    .compileComponents();
+
+    guard = TestBed.inject(NavigationBlockedGuard);
+  });
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(HasNavigationBlockedMockComponent);
+
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(guard).toBeTruthy();
+  });
+
+  it('should block navigation', (done) => {
+
+    component.hasNavigationBlockedValue = true;
+
+    guard.canDeactivate(component, {} as any, {} as any)
+      .then((canDeactivate) => {
+        expect(canDeactivate).toBeFalsy();
+        done();
+      })
+      .catch(done);
+  });
+
+  it('should unblock navigation', (done) => {
+
+    component.hasNavigationBlockedValue = false;
+
+    guard.canDeactivate(component, {} as any, {} as any)
+      .then((canDeactivate) => {
+        expect(canDeactivate).toBeTruthy();
+        done();
+      })
+      .catch(done);
+  });
+
+});

src/app/guards/navigation-blocked/navigation-blocked.guard.ts

@@ -0,0 +1,22 @@
+import { Injectable } from '@angular/core';
+import { ActivatedRouteSnapshot, RouterStateSnapshot, CanDeactivate } from '@angular/router';
+import { Observable } from 'rxjs';
+
+export interface HasNavigationBlocked {
+  hasNavigationBlocked: () => Observable<boolean> | Promise<boolean> | boolean;
+}
+
+@Injectable({
+  providedIn: 'root'
+})
+export class NavigationBlockedGuard implements CanDeactivate<HasNavigationBlocked> {
+  constructor() {}
+
+  async canDeactivate(component: HasNavigationBlocked,
+                      route: ActivatedRouteSnapshot,
+                      state: RouterStateSnapshot) {
+
+    return !component.hasNavigationBlocked();
+  }
+}
+