fix(angular): NavController works with nested outlets (#28421)

Issue number: resolves #28417

---------

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issue. -->

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

The common `IonRouterOutlet` was trying to inject another common
`IonRouterOutlet` into `parentOutlet`:
dc94ae01fe/packages/angular/common/src/directives/navigation/router-outlet.ts (L119)
None existed, so this field was `null`.

This is a problem if developers are using the module `IonRouterOutlet`
since parent router outlets will not be currently injected because
Angular is trying to use the common `IonRouterOutlet` not the module
`IonRouterOutlet`:
https://github.com/ionic-team/ionic-framework/blob/main/packages/angular/src/directives/navigation/ion-router-outlet.ts.
The same goes for the standalone `IonRouterOutlet`.

This resulted in things such as `NavController.pop` not working in
nested outlets because the parentOutlet was not defined.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- `IonRouterOutlet` now injects the correct router outlet instance for
`parentOutlet`

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!-- If this introduces a breaking change, please describe the impact
and migration path for existing applications below. -->


## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

Dev build: `7.5.3-dev.11698328998.1a79f815`

packages/angular/src/directives/navigation/ion-router-outlet.ts

@@ -1,8 +1,29 @@
-import { Directive } from '@angular/core';
+import { Location } from '@angular/common';
+import { Directive, Attribute, Optional, SkipSelf, ElementRef, NgZone } from '@angular/core';
+import { Router, ActivatedRoute } from '@angular/router';
 import { IonRouterOutlet as IonRouterOutletBase } from '@ionic/angular/common';
 
 @Directive({
   selector: 'ion-router-outlet',
 })
 // eslint-disable-next-line @angular-eslint/directive-class-suffix
-export class IonRouterOutlet extends IonRouterOutletBase {}
+export class IonRouterOutlet extends IonRouterOutletBase {
+  /**
+   * We need to pass in the correct instance of IonRouterOutlet
+   * otherwise parentOutlet will be null in a nested outlet context.
+   * This results in APIs such as NavController.pop not working
+   * in nested outlets because the parent outlet cannot be found.
+   */
+  constructor(
+    @Attribute('name') name: string,
+    @Optional() @Attribute('tabs') tabs: string,
+    commonLocation: Location,
+    elementRef: ElementRef,
+    router: Router,
+    zone: NgZone,
+    activatedRoute: ActivatedRoute,
+    @SkipSelf() @Optional() readonly parentOutlet?: IonRouterOutlet
+  ) {
+    super(name, tabs, commonLocation, elementRef, router, zone, activatedRoute, parentOutlet);
+  }
+}

packages/angular/standalone/src/navigation/router-outlet.ts

@@ -1,4 +1,6 @@
-import { Directive } from '@angular/core';
+import { Location } from '@angular/common';
+import { Directive, Attribute, Optional, SkipSelf, ElementRef, NgZone } from '@angular/core';
+import { Router, ActivatedRoute } from '@angular/router';
 import { IonRouterOutlet as IonRouterOutletBase, ProxyCmp } from '@ionic/angular/common';
 import { defineCustomElement } from '@ionic/core/components/ion-router-outlet.js';
 
@@ -10,4 +12,23 @@ import { defineCustomElement } from '@ionic/core/components/ion-router-outlet.js
   standalone: true,
 })
 // eslint-disable-next-line @angular-eslint/directive-class-suffix
-export class IonRouterOutlet extends IonRouterOutletBase {}
+export class IonRouterOutlet extends IonRouterOutletBase {
+  /**
+   * We need to pass in the correct instance of IonRouterOutlet
+   * otherwise parentOutlet will be null in a nested outlet context.
+   * This results in APIs such as NavController.pop not working
+   * in nested outlets because the parent outlet cannot be found.
+   */
+  constructor(
+    @Attribute('name') name: string,
+    @Optional() @Attribute('tabs') tabs: string,
+    commonLocation: Location,
+    elementRef: ElementRef,
+    router: Router,
+    zone: NgZone,
+    activatedRoute: ActivatedRoute,
+    @SkipSelf() @Optional() readonly parentOutlet?: IonRouterOutlet
+  ) {
+    super(name, tabs, commonLocation, elementRef, router, zone, activatedRoute, parentOutlet);
+  }
+}

packages/angular/test/base/e2e/src/lazy/nested-outlet.spec.ts

@@ -27,5 +27,9 @@ describe('Nested Outlet', () => {
     cy.get('#goto-nested-page2').click();
   });
 
+  // Fixes https://github.com/ionic-team/ionic-framework/issues/28417
+  it('parentOutlet should be defined', () => {
+    cy.get('#parent-outlet span').should('have.text', 'true');
+  });
 });
 

packages/angular/test/base/e2e/src/standalone/tabs.spec.ts

@@ -13,4 +13,9 @@ describe('Tabs', () => {
     cy.get('app-tab-two').should('be.visible');
     cy.contains('Tab 2');
   });
+
+  // Fixes https://github.com/ionic-team/ionic-framework/issues/28417
+  it('parentOutlet should be defined', () => {
+    cy.get('#parent-outlet span').should('have.text', 'true');
+  });
 });

packages/angular/test/base/src/app/lazy/nested-outlet-page/nested-outlet-page.component.html

@@ -4,4 +4,7 @@
     <ion-button routerLink="/lazy/tabs" id="goto-tabs">Go To Tabs</ion-button>
     <ion-button routerLink="/lazy/nested-outlet/page2" id="goto-nested-page2">Go To SECOND</ion-button>
   </p>
+  <p id="parent-outlet">
+    Has Parent Outlet: <span>{{ hasParentOutlet }}</span>
+  </p>
 </ion-content>

packages/angular/test/base/src/app/lazy/nested-outlet-page/nested-outlet-page.component.ts

@@ -1,10 +1,16 @@
 import { Component, NgZone, OnDestroy, OnInit } from '@angular/core';
+import { IonRouterOutlet } from '@ionic/angular';
 
 @Component({
   selector: 'app-nested-outlet-page',
   templateUrl: './nested-outlet-page.component.html',
 })
 export class NestedOutletPageComponent implements OnDestroy, OnInit {
+  hasParentOutlet = false;
+
+  constructor(private routerOutlet: IonRouterOutlet) {
+    this.hasParentOutlet = routerOutlet.parentOutlet != null;
+  }
 
   ngOnInit() {
     NgZone.assertInAngularZone();

packages/angular/test/base/src/app/standalone/tabs/tab1.component.ts

@@ -1,12 +1,21 @@
 import { Component } from '@angular/core';
+import { IonRouterOutlet } from '@ionic/angular/standalone';
 
 @Component({
   selector: 'app-tab-one',
   template: `
     Tab 1
+
+    <p id="parent-outlet">
+      Has Parent Outlet: <span>{{ hasParentOutlet }}</span>
+    </p>
   `,
   standalone: true,
 })
 export class TabOneComponent {
+  hasParentOutlet = false;
 
+  constructor(private routerOutlet: IonRouterOutlet) {
+    this.hasParentOutlet = routerOutlet.parentOutlet != null;
+  }
 }