fix(common): image placeholder not removed in OnPush component (#54515)

crisbeto · alxhub · commit 219445cda497 · 2024-02-20T09:49:58.000-08:00
Fixes that the placeholder wasn't being removed when an optimized image is placed in an `OnPush` component. Fixes #54478. PR Close #54515
diff --git a/packages/common/src/directives/ng_optimized_image/ng_optimized_image.ts b/packages/common/src/directives/ng_optimized_image/ng_optimized_image.ts
@@ -29,6 +29,7 @@ import {
   ɵRuntimeError as RuntimeError,
   ɵSafeValue as SafeValue,
   ɵunwrapSafeValue as unwrapSafeValue,
+  ChangeDetectorRef,
 } from '@angular/core';
 
 import {RuntimeErrorCode} from '../../errors';
@@ -433,7 +434,7 @@ export class NgOptimizedImage implements OnInit, OnChanges, OnDestroy {
       }
     }
     if (this.placeholder) {
-      this.removePlaceholderOnLoad(this, this.imgElement, this.renderer);
+      this.removePlaceholderOnLoad(this.imgElement);
     }
     this.setHostAttributes();
   }
@@ -648,22 +649,17 @@ export class NgOptimizedImage implements OnInit, OnChanges, OnDestroy {
     return Boolean(placeholderConfig.blur);
   }
 
-  private removePlaceholderOnLoad(
-    dir: NgOptimizedImage,
-    img: HTMLImageElement,
-    renderer: Renderer2,
-  ): void {
-    const removeLoadListenerFn = renderer.listen(img, 'load', () => {
+  private removePlaceholderOnLoad(img: HTMLImageElement): void {
+    const callback = () => {
+      const changeDetectorRef = this.injector.get(ChangeDetectorRef);
       removeLoadListenerFn();
       removeErrorListenerFn();
-      dir.placeholder = false;
-    });
+      this.placeholder = false;
+      changeDetectorRef.markForCheck();
+    };
 
-    const removeErrorListenerFn = renderer.listen(img, 'error', () => {
-      removeLoadListenerFn();
-      removeErrorListenerFn();
-      dir.placeholder = false;
-    });
+    const removeLoadListenerFn = this.renderer.listen(img, 'load', callback);
+    const removeErrorListenerFn = this.renderer.listen(img, 'error', callback);
   }
 
   /** @nodoc */
diff --git a/packages/common/test/directives/ng_optimized_image_spec.ts b/packages/common/test/directives/ng_optimized_image_spec.ts
@@ -9,7 +9,7 @@
 import {CommonModule, DOCUMENT, IMAGE_CONFIG, ImageConfig} from '@angular/common';
 import {RuntimeErrorCode} from '@angular/common/src/errors';
 import {PLATFORM_SERVER_ID} from '@angular/common/src/platform_id';
-import {Component, PLATFORM_ID, Provider, Type} from '@angular/core';
+import {ChangeDetectionStrategy, Component, PLATFORM_ID, Provider, Type} from '@angular/core';
 import {ComponentFixture, TestBed} from '@angular/core/testing';
 import {DomSanitizer, SafeResourceUrl} from '@angular/platform-browser';
 import {expect} from '@angular/platform-browser/testing/src/matchers';
@@ -1078,7 +1078,6 @@ describe('Image directive', () => {
         fixture.detectChanges();
         const nativeElement = fixture.nativeElement as HTMLElement;
         const img = nativeElement.querySelector('img')!;
-        const styles = parseInlineStyles(img);
         // Double quotes removed to account for different browser behavior.
         expect(img.getAttribute('style')?.replace(/"/g, '').replace(/\s/g, '')).toBe(
           `background-size:cover;background-position:50%50%;background-repeat:no-repeat;background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEU);filter:blur(${PLACEHOLDER_BLUR_AMOUNT}px);`,
@@ -1100,6 +1099,19 @@ describe('Image directive', () => {
       );
     });
 
+    it('should replace the placeholder with the actual image on load', () => {
+      setupTestingModule();
+      const template = '<img ngSrc="path/img.png" width="400" height="300" placeholder="true" />';
+      const fixture = createTestComponent(template, ChangeDetectionStrategy.OnPush);
+      fixture.detectChanges();
+      const nativeElement = fixture.nativeElement as HTMLElement;
+      const img = nativeElement.querySelector('img')!;
+      expect(parseInlineStyles(img).has('background-image')).toBe(true);
+      img.dispatchEvent(new Event('load'));
+      fixture.detectChanges();
+      expect(parseInlineStyles(img).has('background-image')).toBe(false);
+    });
+
     it('should use the placeholderResolution set in imageConfig', () => {
       const imageConfig = {
         placeholderResolution: 30,
@@ -2177,10 +2189,13 @@ function setUpModuleNoLoader() {
   });
 }
 
-function createTestComponent(template: string): ComponentFixture<TestComponent> {
-  return TestBed.overrideComponent(TestComponent, {set: {template: template}}).createComponent(
-    TestComponent,
-  );
+function createTestComponent(
+  template: string,
+  changeDetection = ChangeDetectionStrategy.OnPush,
+): ComponentFixture<TestComponent> {
+  return TestBed.overrideComponent(TestComponent, {
+    set: {template, changeDetection},
+  }).createComponent(TestComponent);
 }
 
 function parseInlineStyles(img: HTMLImageElement): Map<string, string> {
