fix(modal): allow interaction with parent content through sheet modals in child routes

core/src/components/modal/modal.tsx

@@ -71,7 +71,7 @@ export class Modal implements ComponentInterface, OverlayInterface {
   private gesture?: Gesture;
   private coreDelegate: FrameworkDelegate = CoreDelegate();
   private sheetTransition?: Promise<any>;
-  private isSheetModal = false;
+  @State() private isSheetModal = false;
   private currentBreakpoint?: number;
   private wrapperEl?: HTMLElement;
   private backdropEl?: HTMLIonBackdropElement;
@@ -100,6 +100,8 @@ export class Modal implements ComponentInterface, OverlayInterface {
   private parentRemovalObserver?: MutationObserver;
   // Cached original parent from before modal is moved to body during presentation
   private cachedOriginalParent?: HTMLElement;
+  // Cached ion-page ancestor for child route passthrough
+  private cachedPageParent?: HTMLElement | null;
 
   lastFocus?: HTMLElement;
   animation?: Animation;
@@ -644,7 +646,14 @@ export class Modal implements ComponentInterface, OverlayInterface {
       window.addEventListener(KEYBOARD_DID_OPEN, this.keyboardOpenCallback);
     }
 
-    if (this.isSheetModal) {
+    /**
+     * Recalculate isSheetModal because framework bindings (e.g., Angular)
+     * may not have been applied when componentWillLoad ran.
+     */
+    const isSheetModal = this.breakpoints !== undefined && this.initialBreakpoint !== undefined;
+    this.isSheetModal = isSheetModal;
+
+    if (isSheetModal) {
       this.initSheetGesture();
     } else if (hasCardModal) {
       this.initSwipeToClose();
@@ -753,6 +762,91 @@ export class Modal implements ComponentInterface, OverlayInterface {
     this.moveSheetToBreakpoint = moveSheetToBreakpoint;
 
     this.gesture.enable(true);
+
+    /**
+     * When backdrop interaction is allowed, nested router outlets from child routes
+     * may block pointer events to parent content. Apply passthrough styles only when
+     * the modal was the sole content of a child route page.
+     * See https://github.com/ionic-team/ionic-framework/issues/30700
+     */
+    const backdropNotBlocking = this.showBackdrop === false || this.focusTrap === false || backdropBreakpoint > 0;
+    if (backdropNotBlocking) {
+      this.setupChildRoutePassthrough();
+    }
+  }
+
+  /**
+   * For sheet modals that allow background interaction, sets up pointer-events
+   * passthrough on child route page wrappers and nested router outlets.
+   */
+  private setupChildRoutePassthrough() {
+    // Cache the page parent for cleanup
+    this.cachedPageParent = this.getOriginalPageParent();
+    const pageParent = this.cachedPageParent;
+
+    // Skip ion-app (controller modals) and pages with visible sibling content next to the modal
+    if (!pageParent || pageParent.tagName === 'ION-APP') {
+      return;
+    }
+
+    const hasVisibleContent = Array.from(pageParent.children).some(
+      (child) =>
+        child !== this.el &&
+        !(child instanceof HTMLElement && window.getComputedStyle(child).display === 'none') &&
+        child.tagName !== 'TEMPLATE' &&
+        child.tagName !== 'SLOT' &&
+        !(child.nodeType === Node.TEXT_NODE && !child.textContent?.trim())
+    );
+
+    if (hasVisibleContent) {
+      return;
+    }
+
+    // Child route case: page only contained the modal
+    pageParent.classList.add('ion-page-overlay-passthrough');
+
+    // Also make nested router outlets passthrough
+    const routerOutlet = pageParent.parentElement;
+    if (routerOutlet?.tagName === 'ION-ROUTER-OUTLET' && routerOutlet.parentElement?.tagName !== 'ION-APP') {
+      routerOutlet.style.setProperty('pointer-events', 'none');
+      routerOutlet.setAttribute('data-overlay-passthrough', 'true');
+    }
+  }
+
+  /**
+   * Finds the ion-page ancestor of the modal's original parent location.
+   */
+  private getOriginalPageParent(): HTMLElement | null {
+    if (!this.cachedOriginalParent) {
+      return null;
+    }
+
+    let pageParent: HTMLElement | null = this.cachedOriginalParent;
+    while (pageParent && !pageParent.classList.contains('ion-page')) {
+      pageParent = pageParent.parentElement;
+    }
+    return pageParent;
+  }
+
+  /**
+   * Removes passthrough styles added by setupChildRoutePassthrough.
+   */
+  private cleanupChildRoutePassthrough() {
+    const pageParent = this.cachedPageParent;
+    if (!pageParent) {
+      return;
+    }
+
+    pageParent.classList.remove('ion-page-overlay-passthrough');
+
+    const routerOutlet = pageParent.parentElement;
+    if (routerOutlet?.hasAttribute('data-overlay-passthrough')) {
+      routerOutlet.style.removeProperty('pointer-events');
+      routerOutlet.removeAttribute('data-overlay-passthrough');
+    }
+
+    // Clear the cached reference
+    this.cachedPageParent = undefined;
   }
 
   private sheetOnDismiss() {
@@ -862,6 +956,8 @@ export class Modal implements ComponentInterface, OverlayInterface {
       }
       this.cleanupViewTransitionListener();
       this.cleanupParentRemovalObserver();
+
+      this.cleanupChildRoutePassthrough();
     }
     this.currentBreakpoint = undefined;
     this.animation = undefined;

core/src/css/core.scss

@@ -181,6 +181,15 @@ html.ios ion-modal.modal-card .ion-page {
   z-index: $z-index-page-container;
 }
 
+/**
+ * Allows pointer events to pass through child route page wrappers
+ * when they only contain a sheet modal that permits background interaction.
+ * https://github.com/ionic-team/ionic-framework/issues/30700
+ */
+.ion-page.ion-page-overlay-passthrough {
+  pointer-events: none;
+}
+
 /**
  * When making custom dialogs, using
  * ion-content is not required. As a result,

core/src/utils/overlays.ts

@@ -38,6 +38,20 @@ let lastId = 0;
 
 export const activeAnimations = new WeakMap<OverlayInterface, Animation[]>();
 
+type OverlayWithFocusTrapProps = HTMLIonOverlayElement & {
+  focusTrap?: boolean;
+  showBackdrop?: boolean;
+  backdropBreakpoint?: number;
+};
+
+/**
+ * Determines if the overlay's backdrop is always blocking (no background interaction).
+ * Returns false if showBackdrop=false or backdropBreakpoint > 0.
+ */
+const isBackdropAlwaysBlocking = (el: OverlayWithFocusTrapProps): boolean => {
+  return el.showBackdrop !== false && !((el.backdropBreakpoint ?? 0) > 0);
+};
+
 const createController = <Opts extends object, HTMLElm>(tagName: string) => {
   return {
     create(options: Opts): Promise<HTMLElm> {
@@ -539,11 +553,9 @@ export const present = async <OverlayPresentOptions>(
    * view container subtree, skip adding aria-hidden/inert there
    * to avoid disabling the overlay.
    */
-  const overlayEl = overlay.el as HTMLIonOverlayElement & { focusTrap?: boolean; showBackdrop?: boolean };
+  const overlayEl = overlay.el as OverlayWithFocusTrapProps;
   const shouldTrapFocus = overlayEl.tagName !== 'ION-TOAST' && overlayEl.focusTrap !== false;
-  // Only lock out root content when backdrop is active. Developers relying on showBackdrop=false
-  // expect background interaction to remain enabled.
-  const shouldLockRoot = shouldTrapFocus && overlayEl.showBackdrop !== false;
+  const shouldLockRoot = shouldTrapFocus && isBackdropAlwaysBlocking(overlayEl);
 
   overlay.presented = true;
   overlay.willPresent.emit();
@@ -680,12 +692,12 @@ export const dismiss = async <OverlayDismissOptions>(
    * is dismissed.
    */
   const overlaysLockingRoot = presentedOverlays.filter((o) => {
-    const el = o as HTMLIonOverlayElement & { focusTrap?: boolean; showBackdrop?: boolean };
-    return el.tagName !== 'ION-TOAST' && el.focusTrap !== false && el.showBackdrop !== false;
+    const el = o as OverlayWithFocusTrapProps;
+    return el.tagName !== 'ION-TOAST' && el.focusTrap !== false && isBackdropAlwaysBlocking(el);
   });
-  const overlayEl = overlay.el as HTMLIonOverlayElement & { focusTrap?: boolean; showBackdrop?: boolean };
+  const overlayEl = overlay.el as OverlayWithFocusTrapProps;
   const locksRoot =
-    overlayEl.tagName !== 'ION-TOAST' && overlayEl.focusTrap !== false && overlayEl.showBackdrop !== false;
+    overlayEl.tagName !== 'ION-TOAST' && overlayEl.focusTrap !== false && isBackdropAlwaysBlocking(overlayEl);
 
   /**
    * If this is the last visible overlay that is trapping focus

packages/angular/test/base/e2e/src/standalone/modal-child-route.spec.ts

@@ -0,0 +1,38 @@
+import { expect, test } from '@playwright/test';
+
+/**
+ * Tests for sheet modals in child routes with showBackdrop=false.
+ * Parent has buttons + nested outlet; child route contains only the modal.
+ * See https://github.com/ionic-team/ionic-framework/issues/30700
+ */
+test.describe('Modals: Inline Sheet in Child Route (standalone)', () => {
+  test.beforeEach(async ({ page }) => {
+    await page.goto('/standalone/modal-child-route/child');
+  });
+
+  test('should render parent content and child modal', async ({ page }) => {
+    await expect(page.locator('#increment-btn')).toBeVisible();
+    await expect(page.locator('#decrement-btn')).toBeVisible();
+    await expect(page.locator('#background-action-count')).toHaveText('0');
+    await expect(page.locator('ion-modal.show-modal')).toBeVisible();
+    await expect(page.locator('#modal-content-loaded')).toBeVisible();
+  });
+
+  test('should allow interacting with parent content while modal is open in child route', async ({ page }) => {
+    await expect(page.locator('ion-modal.show-modal')).toBeVisible();
+
+    await page.locator('#increment-btn').click();
+    await expect(page.locator('#background-action-count')).toHaveText('1');
+  });
+
+  test('should allow multiple interactions with parent content while modal is open', async ({ page }) => {
+    await expect(page.locator('ion-modal.show-modal')).toBeVisible();
+
+    await page.locator('#increment-btn').click();
+    await page.locator('#increment-btn').click();
+    await expect(page.locator('#background-action-count')).toHaveText('2');
+
+    await page.locator('#decrement-btn').click();
+    await expect(page.locator('#background-action-count')).toHaveText('1');
+  });
+});

packages/angular/test/base/src/app/standalone/app-standalone/app.routes.ts

@@ -13,6 +13,14 @@ export const routes: Routes = [
       { path: 'modal', loadComponent: () => import('../modal/modal.component').then(c => c.ModalComponent) },
       { path: 'modal-sheet-inline', loadComponent: () => import('../modal-sheet-inline/modal-sheet-inline.component').then(c => c.ModalSheetInlineComponent) },
       { path: 'modal-dynamic-wrapper', loadComponent: () => import('../modal-dynamic-wrapper/modal-dynamic-wrapper.component').then(c => c.ModalDynamicWrapperComponent) },
+      { path: 'modal-child-route', redirectTo: '/standalone/modal-child-route/child', pathMatch: 'full' },
+      {
+        path: 'modal-child-route',
+        loadComponent: () => import('../modal-child-route/modal-child-route-parent.component').then(c => c.ModalChildRouteParentComponent),
+        children: [
+          { path: 'child', loadComponent: () => import('../modal-child-route/modal-child-route-child.component').then(c => c.ModalChildRouteChildComponent) },
+        ]
+      },
       { path: 'programmatic-modal', loadComponent: () => import('../programmatic-modal/programmatic-modal.component').then(c => c.ProgrammaticModalComponent) },
       { path: 'router-outlet', loadComponent: () => import('../router-outlet/router-outlet.component').then(c => c.RouterOutletComponent) },
       { path: 'back-button', loadComponent: () => import('../back-button/back-button.component').then(c => c.BackButtonComponent) },

packages/angular/test/base/src/app/standalone/home-page/home-page.component.html

@@ -100,6 +100,11 @@
         Modal Dynamic Wrapper Test
       </ion-label>
     </ion-item>
+    <ion-item routerLink="/standalone/modal-child-route">
+      <ion-label>
+        Modal Child Route Test
+      </ion-label>
+    </ion-item>
     <ion-item routerLink="/standalone/programmatic-modal">
       <ion-label>
         Programmatic Modal Test

packages/angular/test/base/src/app/standalone/modal-child-route/modal-child-route-child.component.ts

@@ -0,0 +1,33 @@
+import { CommonModule } from '@angular/common';
+import { Component } from '@angular/core';
+import { IonContent, IonHeader, IonModal, IonTitle, IonToolbar } from '@ionic/angular/standalone';
+
+/**
+ * Child route component containing only the sheet modal with showBackdrop=false.
+ * Verifies issue https://github.com/ionic-team/ionic-framework/issues/30700
+ */
+@Component({
+  selector: 'app-modal-child-route-child',
+  template: `
+    <ion-modal
+      [isOpen]="true"
+      [breakpoints]="[0.2, 0.5, 0.7]"
+      [initialBreakpoint]="0.5"
+      [showBackdrop]="false"
+    >
+      <ng-template>
+        <ion-header>
+          <ion-toolbar>
+            <ion-title>Modal in Child Route</ion-title>
+          </ion-toolbar>
+        </ion-header>
+        <ion-content class="ion-padding">
+          <p id="modal-content-loaded">Modal content loaded in child route</p>
+        </ion-content>
+      </ng-template>
+    </ion-modal>
+  `,
+  standalone: true,
+  imports: [CommonModule, IonContent, IonHeader, IonModal, IonTitle, IonToolbar],
+})
+export class ModalChildRouteChildComponent {}

packages/angular/test/base/src/app/standalone/modal-child-route/modal-child-route-parent.component.ts

@@ -0,0 +1,38 @@
+import { Component } from '@angular/core';
+import { IonButton, IonContent, IonHeader, IonRouterOutlet, IonTitle, IonToolbar } from '@ionic/angular/standalone';
+
+/**
+ * Parent with interactive buttons and nested outlet for child route modal.
+ * See https://github.com/ionic-team/ionic-framework/issues/30700
+ */
+@Component({
+  selector: 'app-modal-child-route-parent',
+  template: `
+    <ion-header>
+      <ion-toolbar>
+        <ion-title>Parent Page with Nested Route</ion-title>
+      </ion-toolbar>
+    </ion-header>
+    <ion-content class="ion-padding">
+      <div style="display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px;">
+        <ion-button id="decrement-btn" (click)="decrement()">-</ion-button>
+        <p id="background-action-count">{{ count }}</p>
+        <ion-button id="increment-btn" (click)="increment()">+</ion-button>
+      </div>
+      <ion-router-outlet></ion-router-outlet>
+    </ion-content>
+  `,
+  standalone: true,
+  imports: [IonButton, IonContent, IonHeader, IonRouterOutlet, IonTitle, IonToolbar],
+})
+export class ModalChildRouteParentComponent {
+  count = 0;
+
+  increment() {
+    this.count++;
+  }
+
+  decrement() {
+    this.count--;
+  }
+}