fix(router-outlet): attach entering view before first change detection (#18821)

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

@@ -205,7 +205,6 @@ export class IonRouterOutlet implements OnDestroy, OnInit {
       // Calling `markForCheck` to make sure we will run the change detection when the
       // `RouterOutlet` is inside a `ChangeDetectionStrategy.OnPush` component.
       enteringView = this.stackCtrl.createView(this.activated, activatedRoute);
-      enteringView.ref.changeDetectorRef.detectChanges();
 
       // Store references to the proxy by component
       this.proxyMap.set(cmpRef.instance, activatedRouteProxy);

angular/src/directives/navigation/stack-controller.ts

@@ -31,7 +31,7 @@ export class StackController {
   createView(ref: ComponentRef<any>, activatedRoute: ActivatedRoute): RouteView {
     const url = getUrl(this.router, activatedRoute);
     const element = (ref && ref.location && ref.location.nativeElement) as HTMLElement;
-    const unlistenEvents = bindLifecycleEvents(ref.instance, element);
+    const unlistenEvents = bindLifecycleEvents(this.zone, ref.instance, element);
     return {
       id: this.nextId++,
       stackId: computeStackId(this.tabsPrefix, url),
@@ -90,16 +90,28 @@ export class StackController {
       }
     }
 
+    const reused = this.views.includes(enteringView);
     const views = this.insertView(enteringView, direction);
-    return this.wait(() => {
-      return this.transition(enteringView, leavingView, animation, this.canGoBack(1), false)
-        .then(() => cleanupAsync(enteringView, views, viewsSnapshot, this.location))
-        .then(() => ({
-          enteringView,
-          direction,
-          animation,
-          tabSwitch
-        }));
+
+    // Trigger change detection before transition starts
+    // This will call ngOnInit() the first time too, just after the view
+    // was attached to the dom, but BEFORE the transition starts
+    if (!reused) {
+      enteringView.ref.changeDetectorRef.detectChanges();
+    }
+
+    // Wait until previous transitions finish
+    return this.zone.runOutsideAngular(() => {
+      return this.wait(() => {
+        return this.transition(enteringView, leavingView, animation, this.canGoBack(1), false)
+          .then(() => cleanupAsync(enteringView, views, viewsSnapshot, this.location))
+          .then(() => ({
+            enteringView,
+            direction,
+            animation,
+            tabSwitch
+          }));
+      });
     });
   }
 
@@ -199,11 +211,11 @@ export class StackController {
     if (enteringView) {
       enteringView.ref.changeDetectorRef.reattach();
     }
-    // TODO: disconnect leaving page from change detection to
+    // disconnect leaving page from change detection to
     // reduce jank during the page transition
-    // if (leavingView) {
-    //   leavingView.ref.changeDetectorRef.detach();
-    // }
+    if (leavingView) {
+      leavingView.ref.changeDetectorRef.detach();
+    }
     const enteringEl = enteringView ? enteringView.element : undefined;
     const leavingEl = leavingView ? leavingView.element : undefined;
     const containerEl = this.containerEl;
@@ -213,13 +225,13 @@ export class StackController {
         containerEl.appendChild(enteringEl);
       }
 
-      return this.zone.runOutsideAngular(() => containerEl.commit(enteringEl, leavingEl, {
+      return containerEl.commit(enteringEl, leavingEl, {
         deepWait: true,
         duration: direction === undefined ? 0 : undefined,
         direction,
         showGoBack,
         progressAnimation
-      }));
+      });
     }
     return Promise.resolve(false);
   }

angular/src/providers/angular-delegate.ts

@@ -34,10 +34,10 @@ export class AngularFrameworkDelegate implements FrameworkDelegate {
   ) {}
 
   attachViewToDom(container: any, component: any, params?: any, cssClasses?: string[]): Promise<any> {
-    return new Promise(resolve => {
-      this.zone.run(() => {
+    return this.zone.run(() => {
+      return new Promise(resolve => {
         const el = attachView(
-          this.resolver, this.injector, this.location, this.appRef,
+          this.zone, this.resolver, this.injector, this.location, this.appRef,
           this.elRefMap, this.elEventsMap,
           container, component, params, cssClasses
         );
@@ -47,8 +47,8 @@ export class AngularFrameworkDelegate implements FrameworkDelegate {
   }
 
   removeViewFromDom(_container: any, component: any): Promise<void> {
-    return new Promise(resolve => {
-      this.zone.run(() => {
+    return this.zone.run(() => {
+      return new Promise(resolve => {
         const componentRef = this.elRefMap.get(component);
         if (componentRef) {
           componentRef.destroy();
@@ -66,6 +66,7 @@ export class AngularFrameworkDelegate implements FrameworkDelegate {
 }
 
 export function attachView(
+  zone: NgZone,
   resolver: ComponentFactoryResolver,
   injector: Injector,
   location: ViewContainerRef | undefined,
@@ -93,7 +94,7 @@ export function attachView(
       hostElement.classList.add(clazz);
     }
   }
-  const unbindEvents = bindLifecycleEvents(instance, hostElement);
+  const unbindEvents = bindLifecycleEvents(zone, instance, hostElement);
   container.appendChild(hostElement);
 
   if (!location) {
@@ -113,15 +114,17 @@ const LIFECYCLES = [
   LIFECYCLE_WILL_UNLOAD
 ];
 
-export function bindLifecycleEvents(instance: any, element: HTMLElement) {
-  const unregisters = LIFECYCLES
-    .filter(eventName => typeof instance[eventName] === 'function')
-    .map(eventName => {
-      const handler = (ev: any) => instance[eventName](ev.detail);
-      element.addEventListener(eventName, handler);
-      return () => element.removeEventListener(eventName, handler);
-    });
-  return () => unregisters.forEach(fn => fn());
+export function bindLifecycleEvents(zone: NgZone, instance: any, element: HTMLElement) {
+  return zone.run(() => {
+    const unregisters = LIFECYCLES
+      .filter(eventName => typeof instance[eventName] === 'function')
+      .map(eventName => {
+        const handler = (ev: any) => instance[eventName](ev.detail);
+        element.addEventListener(eventName, handler);
+        return () => element.removeEventListener(eventName, handler);
+      });
+    return () => unregisters.forEach(fn => fn());
+  });
 }
 
 const NavParamsToken = new InjectionToken<any>('NavParamsToken');