docs: imrpove accessibility of lifecycle hooks example (#41071)

PR Close #41071

aio/content/examples/lifecycle-hooks/e2e/src/app.e2e-spec.ts

@@ -86,7 +86,7 @@ describe('Lifecycle hooks', () => {
     const parentEle = element(by.tagName('after-view-parent'));
     const buttonEle = parentEle.element(by.tagName('button')); // Reset
     const commentEle = parentEle.element(by.className('comment'));
-    const logEles = parentEle.all(by.css('h4 ~ div'));
+    const logEles = parentEle.all(by.css('h3 ~ div'));
     const childViewInputEle = parentEle.element(by.css('app-child-view input'));
     let logCount: number;
 
@@ -113,7 +113,7 @@ describe('Lifecycle hooks', () => {
     const parentEle = element(by.tagName('after-content-parent'));
     const buttonEle = parentEle.element(by.tagName('button')); // Reset
     const commentEle = parentEle.element(by.className('comment'));
-    const logEles = parentEle.all(by.css('h4 ~ div'));
+    const logEles = parentEle.all(by.css('h3 ~ div'));
     const childViewInputEle = parentEle.element(by.css('app-child input'));
     let logCount = await logEles.count();
 
@@ -136,8 +136,8 @@ describe('Lifecycle hooks', () => {
     const inputEle = element(by.css('spy-parent input'));
     const addHeroButtonEle = element(by.cssContainingText('spy-parent button', 'Add Hero'));
     const resetHeroesButtonEle = element(by.cssContainingText('spy-parent button', 'Reset Heroes'));
-    const heroEles = element.all(by.css('spy-parent div[appSpy'));
+    const heroEles = element.all(by.css('spy-parent div p'));
-    const logEles = element.all(by.css('spy-parent h4 ~ div'));
+    const logEles = element.all(by.css('spy-parent h3 ~ div'));
 
     expect(await heroEles.count()).toBe(2, 'should have two heroes displayed');
     expect(await logEles.count()).toBe(2, 'should have two log entries');
@@ -156,18 +156,19 @@ describe('Lifecycle hooks', () => {
   it('should support "spy counter"', async () => {
     const updateCounterButtonEle = element(by.cssContainingText('counter-parent button', 'Update'));
     const resetCounterButtonEle = element(by.cssContainingText('counter-parent button', 'Reset'));
-    const textEle = element(by.css('counter-parent app-counter > div'));
+    const textEle = element(by.css('counter-parent app-counter p'));
-    const logEles = element.all(by.css('counter-parent h4 ~ div'));
+    const logEles = element.all(by.css('counter-parent .info .log'));
 
     expect(await textEle.getText()).toContain('Counter = 0');
-    expect(await logEles.count()).toBe(2, 'should start with two log entries');
+    expect(await logEles.count()).toBe(3, 'should start with one change log and two lifecycle log entries, including reset');
 
     await updateCounterButtonEle.click();
     expect(await textEle.getText()).toContain('Counter = 1');
-    expect(await logEles.count()).toBe(3, 'should now have 3 log entries');
+    expect(await logEles.count()).toBe(5, 'should now have 2 change log entries and 3 lifecycle log entries, including reset');
 
     await resetCounterButtonEle.click();
     expect(await textEle.getText()).toContain('Counter = 0');
-    expect(await logEles.count()).toBe(7, 'should now have 7 log entries - 3 prev + 1 reset + 2 destroy + 1 init');
+    expect(await logEles.count()).toBe(8, 'should now have 8 log entries - 1 change log + 2 reset + 2 destroy + 3 init');
+
   });
 });

aio/content/examples/lifecycle-hooks/src/app/after-content-parent.component.ts

@@ -16,12 +16,13 @@ import { LoggerService } from './logger.service';
       // #enddocregion parent-template
     + `</div>
 
-    <h4>-- AfterContent Logs --</h4>
+    <div class="info">
-    <p><button (click)="reset()">Reset</button></p>
+      <h3>AfterContent Logs</h3>
-    <div *ngFor="let msg of logger.logs">{{msg}}</div>
+      <button (click)="reset()">Reset</button>
+      <div *ngFor="let msg of logger.logs" class="log">{{msg}}</div>
+    </div>
   </div>
   `,
-  styles: ['.parent {background: burlywood}'],
   providers: [LoggerService]
 })
 export class AfterContentParentComponent {

aio/content/examples/lifecycle-hooks/src/app/after-content.component.ts

@@ -9,9 +9,9 @@ import { LoggerService } from './logger.service';
   selector: 'after-content',
 // #docregion template
   template: `
-    <div>-- projected content begins --</div>
+    <div>projected content begins</div>
       <ng-content></ng-content>
-    <div>-- projected content ends --</div>`
+    <div>projected content ends</div>`
 // #enddocregion template
    + `
     <p *ngIf="comment" class="comment">

aio/content/examples/lifecycle-hooks/src/app/after-view-parent.component.ts

@@ -5,17 +5,16 @@ import { LoggerService } from './logger.service';
 @Component({
   selector: 'after-view-parent',
   template: `
-  <div class="parent">
+  <h2>AfterView</h2>
-    <h2>AfterView</h2>
 
-    <after-view  *ngIf="show"></after-view>
+  <after-view  *ngIf="show"></after-view>
 
-    <h4>-- AfterView Logs --</h4>
+  <div class="info">
-    <p><button (click)="reset()">Reset</button></p>
+    <h3>AfterView Logs</h3>
-    <div *ngFor="let msg of logger.logs">{{msg}}</div>
+    <button (click)="reset()">Reset</button>
+    <div *ngFor="let msg of logger.logs" class="log">{{msg}}</div>
   </div>
   `,
-  styles: ['.parent {background: burlywood}'],
   providers: [LoggerService]
 })
 export class AfterViewParentComponent {

aio/content/examples/lifecycle-hooks/src/app/after-view.component.ts

@@ -9,9 +9,9 @@ import { LoggerService } from './logger.service';
   selector: 'after-view',
 // #docregion template
   template: `
-    <div>-- child view begins --</div>
+    <div>child view begins</div>
       <app-child-view></app-child-view>
-    <div>-- child view ends --</div>`
+    <div>child view ends</div>`
 // #enddocregion template
    + `
     <p *ngIf="comment" class="comment">

aio/content/examples/lifecycle-hooks/src/app/app.component.html

@@ -1,36 +1,42 @@
 <a id="top"></a>
-<h1>Component Lifecycle Hooks</h1>
+<h1>Lifecycle Hooks</h1>
-<a href="#hooks">Peek-a-boo: (most) lifecycle hooks</a><br>
+<a href="#hooks">Peek-a-boo: (most) lifecycle hooks</a>
-<a href="#spy">Spy: directive with OnInit & OnDestroy</a><br>
+<a href="#spy">Spy: directive with OnInit & OnDestroy</a>
-<a href="#onchanges">OnChanges</a><br>
+<a href="#onchanges">OnChanges</a>
-<a href="#docheck">DoCheck</a><br>
+<a href="#docheck">DoCheck</a>
-<a href="#after-view">AfterViewInit & AfterViewChecked</a><br>
+<a href="#after-view">AfterViewInit & AfterViewChecked</a>
-<a href="#after-content">AfterContentInit & AfterContentChecked</a><br>
+<a href="#after-content">AfterContentInit & AfterContentChecked</a>
-<a href="#counter">Counter: OnChanges + Spy directive</a><br>
+<a href="#counter">Counter: OnChanges + Spy directive</a>
 
 <a id="hooks"></a>
 <peek-a-boo-parent></peek-a-boo-parent>
 <a href="#top">back to top</a>
+<hr />
 
 <a id="spy"></a>
 <spy-parent></spy-parent>
 <a href="#top">back to top</a>
+<hr />
 
 <a id="onchanges"></a>
 <on-changes-parent></on-changes-parent>
 <a href="#top">back to top</a>
+<hr />
 
 <a id="docheck"></a>
 <do-check-parent></do-check-parent>
 <a href="#top">back to top</a>
+<hr />
 
 <a id="after-view"></a>
 <after-view-parent></after-view-parent>
 <a href="#top">back to top</a>
+<hr />
 
 <a id="after-content"></a>
 <after-content-parent></after-content-parent>
 <a href="#top">back to top</a>
+<hr />
 
 <a id="counter"></a>
 <counter-parent></counter-parent>

aio/content/examples/lifecycle-hooks/src/app/child-view.component.ts

@@ -3,7 +3,8 @@ import { Component } from '@angular/core';
 // #docregion child-view
 @Component({
   selector: 'app-child-view',
-  template: '<input [(ngModel)]="hero">'
+  template: `<label for="hero-name">Hero name: </label>
+  <input type="text" id="hero-name" [(ngModel)]="hero">`
 })
 export class ChildViewComponent {
   hero = 'Magneta';

aio/content/examples/lifecycle-hooks/src/app/child.component.ts

@@ -2,7 +2,8 @@ import { Component } from '@angular/core';
 
 @Component({
   selector: 'app-child',
-  template: '<input [(ngModel)]="hero">'
+  template: `<label for="hero-name">Hero name: </label>
+  <input type="text" id="hero-name" [(ngModel)]="hero">`
 })
 export class ChildComponent {
   hero = 'Magneta';

aio/content/examples/lifecycle-hooks/src/app/counter-parent.component.ts

@@ -5,19 +5,18 @@ import { LoggerService } from './logger.service';
 @Component({
   selector: 'counter-parent',
   template: `
-  <div class="parent">
+  <h2>Counter Spy</h2>
-    <h2>Counter Spy</h2>
 
-    <button (click)="updateCounter()">Update counter</button>
+  <button (click)="updateCounter()">Update counter</button>
-    <button (click)="reset()">Reset Counter</button>
+  <button (click)="reset()">Reset Counter</button>
 
-    <app-counter [counter]="value"></app-counter>
+  <app-counter [counter]="value"></app-counter>
 
-    <h4>-- Spy Lifecycle Hook Log --</h4>
+  <div class="info">
-    <div *ngFor="let msg of spyLog">{{msg}}</div>
+    <h3>Spy Lifecycle Hook Log</h3>
+    <div *ngFor="let msg of spyLog" class="log">{{msg}}</div>
   </div>
   `,
-  styles: ['.parent {background: gold;}'],
   providers: [LoggerService]
 })
 export class CounterParentComponent {
@@ -38,7 +37,7 @@ export class CounterParentComponent {
   }
 
   reset() {
-    this.logger.log('-- reset --');
+    this.logger.log('reset');
     this.value = 0;
     this.logger.tick();
   }

aio/content/examples/lifecycle-hooks/src/app/counter.component.ts

@@ -7,14 +7,13 @@ import {
 @Component({
   selector: 'app-counter',
   template: `
-  <div class="counter">
+    <p>Counter = {{counter}}</p>
-    Counter = {{counter}}
 
-    <h5>-- Counter Change Log --</h5>
+    <div class="info">
-    <div *ngFor="let chg of changeLog" appSpy>{{chg}}</div>
+      <h3>Counter Change Log</h3>
-  </div>
+      <div *ngFor="let chg of changeLog" appSpy class="log">{{chg}}</div>
-  `,
+    </div>
-  styles: ['.counter {background: LightYellow; padding: 8px; margin-top: 8px}']
+  `
 })
 export class MyCounterComponent implements OnChanges {
   @Input() counter: number;

aio/content/examples/lifecycle-hooks/src/app/do-check-parent.component.html

@@ -1,11 +1,9 @@
-<div class="parent">
+<h2>{{title}}</h2>
-  <h2>{{title}}</h2>
+<label for="power-input"><label>Power: </label>
+<input type="text" id="power-input" [(ngModel)]="power">
+<label for="hero-name">Hero.name: </label>
+<input type="text" id="hero-name" [(ngModel)]="hero.name">
+<button (click)="reset()">Reset Log</button>
 
-  <table>
+<do-check [hero]="hero" [power]="power"></do-check>
-    <tr><td>Power: </td><td><input [(ngModel)]="power"></td></tr>
-    <tr><td>Hero.name: </td><td><input [(ngModel)]="hero.name"></td></tr>
-  </table>
-  <p><button (click)="reset()">Reset Log</button></p>
 
-  <do-check [hero]="hero" [power]="power"></do-check>
-</div>

aio/content/examples/lifecycle-hooks/src/app/do-check-parent.component.ts

@@ -5,8 +5,7 @@ import { Hero } from './hero';
 
 @Component({
   selector: 'do-check-parent',
-  templateUrl: './do-check-parent.component.html',
+  templateUrl: './do-check-parent.component.html'
-  styles: ['.parent {background: Lavender}']
 })
 export class DoCheckParentComponent {
   hero: Hero;

aio/content/examples/lifecycle-hooks/src/app/do-check.component.ts

@@ -7,17 +7,13 @@ import { Hero } from './hero';
 @Component({
   selector: 'do-check',
   template: `
-  <div class="hero">
+  <div class="info">
     <p>{{hero.name}} can {{power}}</p>
 
-    <h4>-- Change Log --</h4>
+    <h3>Change Log</h3>
-    <div *ngFor="let chg of changeLog">{{chg}}</div>
+    <div *ngFor="let chg of changeLog" class="log">{{chg}}</div>
   </div>
-  `,
+  `
-  styles: [
-    '.hero {background: LightYellow; padding: 8px; margin-top: 8px}',
-    'p {background: Yellow; padding: 8px; margin-top: 8px}'
-  ]
 })
 export class DoCheckComponent implements DoCheck {
   @Input() hero: Hero;

aio/content/examples/lifecycle-hooks/src/app/on-changes-parent.component.html

@@ -1,13 +1,11 @@
-<div class="parent">
+<h2>{{title}}</h2>
-  <h2>{{title}}</h2>
+<label for="power-input">Power: </label>
+<input type="text" id="power-input" [(ngModel)]="power">
+<label for="hero-name"> Hero.name: </label>
+<input type="text" id="hero-name" [(ngModel)]="hero.name">
 
-  <table>
+<button (click)="reset()">Reset Log</button>
-    <tr><td>Power: </td><td><input [(ngModel)]="power"></td></tr>
-    <tr><td>Hero.name: </td><td><input [(ngModel)]="hero.name"></td></tr>
-  </table>
-  <p><button (click)="reset()">Reset Log</button></p>
 
-  <!-- #docregion on-changes -->
+<!-- #docregion on-changes -->
-  <on-changes [hero]="hero" [power]="power"></on-changes>
+<on-changes [hero]="hero" [power]="power"></on-changes>
-  <!-- #enddocregion on-changes -->
+<!-- #enddocregion on-changes -->
-</div>

aio/content/examples/lifecycle-hooks/src/app/on-changes-parent.component.ts

@@ -6,7 +6,7 @@ import { OnChangesComponent } from './on-changes.component';
 @Component({
   selector: 'on-changes-parent',
   templateUrl: './on-changes-parent.component.html',
-  styles: ['.parent {background: Lavender;}']
+  styles: ['']
 })
 export class OnChangesParentComponent {
   hero: Hero;

aio/content/examples/lifecycle-hooks/src/app/on-changes.component.ts

@@ -7,17 +7,13 @@ import { Hero } from './hero';
 @Component({
   selector: 'on-changes',
   template: `
-  <div class="hero">
+  <div class="info">
     <p>{{hero.name}} can {{power}}</p>
 
-    <h4>-- Change Log --</h4>
+    <h3>Change Log</h3>
-    <div *ngFor="let chg of changeLog">{{chg}}</div>
+    <div *ngFor="let chg of changeLog" class="log">{{chg}}</div>
   </div>
-  `,
+  `
-  styles: [
-    '.hero {background: LightYellow; padding: 8px; margin-top: 8px}',
-    'p {background: Yellow; padding: 8px; margin-top: 8px}'
-  ]
 })
 export class OnChangesComponent implements OnChanges {
 // #docregion inputs

aio/content/examples/lifecycle-hooks/src/app/peek-a-boo-parent.component.ts

@@ -6,6 +6,7 @@ import { LoggerService } from './logger.service';
 @Component({
   selector: 'peek-a-boo-parent',
   template: `
+  <hr />
   <div class="parent">
     <h2>Peek-A-Boo</h2>
 
@@ -14,14 +15,14 @@ import { LoggerService } from './logger.service';
     </button>
     <button (click)="updateHero()" [hidden]="!hasChild">Update Hero</button>
 
-    <peek-a-boo *ngIf="hasChild" [name]="heroName">
+    <div class="info">
-    </peek-a-boo>
+      <peek-a-boo *ngIf="hasChild" [name]="heroName"></peek-a-boo>
 
-    <h4>-- Lifecycle Hook Log --</h4>
+      <h3>Lifecycle Hook Log</h3>
-    <div *ngFor="let msg of hookLog">{{msg}}</div>
+      <div *ngFor="let msg of hookLog" class="log">{{msg}}</div>
+    </div>
   </div>
   `,
-  styles: ['.parent {background: moccasin}'],
   providers:  [ LoggerService ]
 })
 export class PeekABooParentComponent {

aio/content/examples/lifecycle-hooks/src/app/peek-a-boo.component.ts

@@ -19,8 +19,7 @@ import { PeekABooDirective } from './peek-a-boo.directive';
 
 @Component({
   selector: 'peek-a-boo',
-  template: '<p>Now you see my hero, {{name}}</p>',
+  template: '<p>Now you see my hero, {{name}}</p>'
-  styles: ['p {background: LightYellow; padding: 8px}']
 })
 // Don't HAVE to mention the Lifecycle Hook interfaces
 // unless we want typing and tool support.

aio/content/examples/lifecycle-hooks/src/app/spy.component.html

@@ -1,16 +1,19 @@
 <div class="parent">
   <h2>Spy Directive</h2>
 
-  <input [(ngModel)]="newName" (keyup.enter)="addHero()">
+  <label for="hero-name">Hero name: </label>
+  <input type="text" id="hero-name" [(ngModel)]="newName" (keyup.enter)="addHero()">
   <button (click)="addHero()">Add Hero</button>
   <button (click)="reset()">Reset Heroes</button>
 
-  <p></p>
+  <div class="info">
-  <!-- #docregion template -->
+    <!-- #docregion template -->
-  <div *ngFor="let hero of heroes" appSpy class="heroes">
+    <p *ngFor="let hero of heroes" appSpy>
-    {{hero}}
+      {{hero}}
+    </p>
+    <!-- #enddocregion template -->
+
+    <h3>Spy Lifecycle Hook Log</h3>
+    <div *ngFor="let msg of logger.logs" class="log">{{msg}}</div>
   </div>
-  <!-- #enddocregion template -->
-  <h4>-- Spy Lifecycle Hook Log --</h4>
-  <div *ngFor="let msg of logger.logs">{{msg}}</div>
 </div>

aio/content/examples/lifecycle-hooks/src/app/spy.component.ts

@@ -6,10 +6,6 @@ import { LoggerService } from './logger.service';
 @Component({
   selector: 'spy-parent',
   templateUrl: './spy.component.html',
-  styles: [
-     '.parent {background: khaki;}',
-     '.heroes {background: LightYellow; padding: 0 8px}'
-  ],
   providers:  [LoggerService]
 })
 export class SpyParentComponent {
@@ -31,7 +27,7 @@ export class SpyParentComponent {
     this.logger.tick();
   }
   reset() {
-    this.logger.log('-- reset --');
+    this.logger.log('reset');
     this.heroes = [];
     this.logger.tick();
   }

aio/content/examples/lifecycle-hooks/src/assets/sample.css

@@ -1,13 +1,61 @@
 .parent {
-  color: #666;
+  padding: 2rem 0;
-  margin: 14px 0;
-  padding: 8px;
 }
-input {
+
-  margin: 4px;
+h2 {
-  padding: 4px;
+  text-align: center;
 }
+
 .comment {
-  color: red;
+  color: #890000;
   font-style: italic;
 }
+
+.log {
+  background-color: #e4e4e4;
+  padding: .25rem;
+}
+
+.info {
+  background: #fff4f4;
+  padding: .75rem;
+  margin-top: 1rem;
+}
+
+p {
+  padding: .25rem;
+}
+
+a {
+  display: block;
+  padding-bottom: .5rem;
+  font-size: 1.1rem;
+  color: #264d73
+}
+
+a:hover {
+  text-decoration: none;
+}
+
+a[href="#top"] {
+  margin: 1rem 0;
+  padding: .5rem;
+  background-color: #264d73;
+  color: #fff;
+}
+
+a[href="#top"]:hover {
+  background-color:#eaeaea;
+  color: black;
+}
+
+a[href="#top"]:active {
+  background-color: black;
+  color: #eaeaea;
+}
+
+input {
+  margin-bottom: 1rem;
+  margin-top: .5rem;
+  font-size: 1rem;
+}