angular-cn/public/docs/_examples/template-syntax/dart/lib/app_component.html

<!-- #docregion my-first-app -->
<h3>My First Angular Application</h3>
<!-- #enddocregion my-first-app -->

<!-- Interpolation and expressions -->
<hr><h2>Interpolation</h2>

<!-- #docregion first-interpolation -->
<p>My current hero is {{currentHero.firstName}}</p>
<!-- #enddocregion first-interpolation -->

<!-- #docregion title+image -->
<h3>
  {{title}}
  <img src="{{heroImageUrl}}" style="height:30px">
</h3>
<!-- #enddocregion title+image -->

<!-- #docregion sum-1 -->
<!-- "The sum of 1 + 1 is 2" -->
<p>The sum of 1 + 1 is {{1 + 1}}</p>
<!-- #enddocregion sum-1 -->

<!-- #docregion sum-2 -->
<!-- "The sum of 1 + 1 is not 4" -->
<p>The sum of 1 + 1 is not {{1 + 1 + getVal}}</p>
<!-- #enddocregion sum-2 -->


<!-- New Mental Model -->
<hr><h2>New Mental Model</h2>

<!--<img src="http://www.wpclipart.com/cartoon/people/hero/hero_silhoutte_T.png">-->
<!-- Public Domain terms of use: http://www.wpclipart.com/terms.html -->
<!-- #docregion img+button -->
<div class="special">Mental Model</div>
<div><b>{{currentHero.fullName}}</b></div>
<img src="assets/images/hero.png">
<button disabled>Save</button>
<!-- #enddocregion img+button -->
<br><br>

<div>
  <!-- #docregion hero-detail-1 -->
  <div class="special">Mental Model</div>
  <hero-detail></hero-detail>
  <!-- #enddocregion hero-detail-1 -->
</div>
<br><br>

<div>
  <!-- #docregion disabled-button-1 -->
  <!-- Bind button disabled state to `isUnchanged` property -->
  <button [disabled]="isUnchanged">Save</button>
  <!-- #enddocregion disabled-button-1 -->
</div>
<br><br>

<div>
  <!-- #docregion property-binding-syntax-1 -->
  <img [src] = "heroImageUrl">
  <hero-detail [hero]="currentHero"></hero-detail>
  <div [ngClass] = "{selected: isSelected}"></div>
  <!-- #enddocregion property-binding-syntax-1 -->
</div>
<br><br>

<!-- See https://github.com/angular/angular/issues/5707 about "myClick (myClick)" -->
<!-- #docregion event-binding-syntax-1 -->
<button (click) = "onSave()">Save</button>
<hero-detail (deleted)="onHeroDeleted()"></hero-detail>
<div myClick (myClick)="clicked=$event">click me</div>
<!-- #enddocregion event-binding-syntax-1 -->
<!-- {{clicked}} --> <!-- causes exception in Dart version -->
<br><br>

<div>
  <!-- #docregion 2-way-binding-syntax-1 -->
  <input [(ngModel)]="heroName">
  <!-- #enddocregion 2-way-binding-syntax-1 -->
  Hero Name: {{heroName}}
</div>
<br><br>

<!-- #docregion attribute-binding-syntax-1 -->
<button [attr.aria-label]="help">help</button>
<!-- #enddocregion attribute-binding-syntax-1 -->
<br><br>

<!-- #docregion class-binding-syntax-1 -->
<div [class.special]="isSpecial">Special</div>
<!-- #enddocregion class-binding-syntax-1 -->
<br><br>

<!-- #docregion style-binding-syntax-1 -->
<button [style.color] = "isSpecial ? 'red' : 'green'">
<!-- #enddocregion style-binding-syntax-1 -->
button</button>

<!-- property vs. attribute -->
<hr><h2>Property vs. Attribute (img examples)</h2>
<!-- examine the following <img> tag in the browser tools -->
<img src="assets/images/ng-logo.png"
     [src]="heroImageUrl">

<br><br>

<img [src]="iconUrl"/>
<img bind-src="heroImageUrl"/>
<img [attr.src]="villainImageUrl"/>



<!-- buttons -->
<hr><h2>Buttons</h2>

<button>Enabled (but does nothing)</button>
<button disabled>Disabled</button>
<button disabled=false>Still disabled</button>
<br><br>
<button disabled>disabled by attribute</button>
<button [disabled]="isUnchanged">disabled by property binding</button>
<br><br>
<button bind-disabled="isUnchanged" on-click="onSave($event)">Disabled Cancel</button>
<button [disabled]="!canSave" (click)="onSave($event)">Enabled Save</button>


<!-- property binding -->
<hr><h2>Property Binding</h2>

<!-- #docregion property-binding-1 -->
<img [src]="heroImageUrl">
<!-- #enddocregion property-binding-1 -->
<!-- #docregion property-binding-2 -->
<button [disabled]="isUnchanged">Cancel</button>
<!-- #enddocregion property-binding-2 -->
<!-- #docregion property-binding-3 -->
<div [ngClass]="'special'">NgClass is special</div>
<!-- #enddocregion property-binding-3 -->
<!-- #docregion property-binding-4 -->
<hero-detail [hero]="selectedHero"></hero-detail>
<!-- #enddocregion property-binding-4 -->
<!-- #docregion property-binding-5 -->
<img bind-src="heroImageUrl">
<!-- #enddocregion property-binding-5 -->

<!-- #docregion property-binding-6 -->
<!-- Doesn't work! HeroDetailComponent expects a Hero, not a string -->
<!--<hero-detail hero="…what do we do here??? …"></hero-detail>--> <!--THROWS ERROR IN DART-->
<!-- #enddocregion property-binding-6 -->

<!-- #docregion property-binding-vs-interpolation -->
<img src="{{heroImageUrl}}">
<img [src]="'' + heroImageUrl">

<div>The title is {{title}}</div>
<div [textContent]="'The title is '+title"></div>
<!-- #enddocregion property-binding-vs-interpolation -->

<!-- attribute binding -->
<hr><h2>Attribute Binding</h2>

<!--  create and set a colspan attribute -->
<!-- #docregion attrib-binding-colspan -->
<table border=1>
  <!--  expression calculates colspan=2 -->
  <tr><td [attr.colspan]="1 + 1">One-Two</td></tr>

  <!-- ERROR: There is no `colspan` property to set!
    <tr><td colspan="{{1 + 1}}">Three-Four</td></tr>
  -->

  <tr><td>Five</td><td>Six</td></tr>
</table>
<!-- #enddocregion attrib-binding-colspan -->

<br>
<!-- #docregion attrib-binding-aria -->
<!-- create and set an aria attribute for assistive technology -->
<button [attr.aria-label]="actionName">{{actionName}} with Aria</button>
<!-- #enddocregion attrib-binding-aria -->
<br><br>

<!-- The following effects are not discussed in the chapter -->
<div>
  <!-- any use of [attr.disabled] creates the disabled attribute -->
  <button [attr.disabled]="isUnchanged">Disabled</button>

  <button [attr.disabled]="!isUnchanged">Disabled as well</button>

  <!-- can't remove it with [attr.disabled] either -->
  <button disabled [attr.disabled]>Still disabled</button>

  <!-- we'd have to remove it with property binding -->
  <button disabled [disabled]="false">Enabled (but inert)</button>
</div>





<!-- class binding -->
<hr><h2>Class Binding</h2>

<!-- #docregion class-binding-1 -->
<!-- standard class attribute setting  -->
<div class="bad curly special">Bad curly special</div>
<!-- #enddocregion class-binding-1 -->

<!-- #docregion class-binding-2 -->
<!-- reset all class names with a string binding  -->
<div class="bad curly special"
     [class]="'bad curly'">Bad curly</div>
<!-- #enddocregion class-binding-2 -->

<!-- #docregion class-binding-3 -->
<!-- #docregion class-binding-3a -->
<!-- toggle the "special" class on/off with a property -->
<div [class.special]="isSpecial">The class binding is special</div>
<!-- #enddocregion class-binding-3a -->

<!-- binding to `class.special` trumps the class attribute -->
<div class="special"
     [class.special]="!isSpecial">This one is not so special</div>
<!-- #enddocregion class-binding-3 -->

<div bind-class.special="isSpecial">This class binding is special too</div>



<!--style binding -->
<hr><h2>Style Binding</h2>

<!-- #docregion style-binding-1 -->
<button [style.color] = "isSpecial ? 'red': 'green'">Red</button>
<button [style.background-color]="canSave ? 'cyan': 'grey'" >Save</button>
<!-- #enddocregion style-binding-1 -->

<!-- #docregion style-binding-2 -->
<button [style.font-size.em]="isSpecial ? 3 : 1" >Big</button>
<button [style.font-size.%]="!isSpecial ? 150 : 50" >Small</button>
<!-- #enddocregion style-binding-2 -->

<!-- event binding -->
<hr><h2>Event Binding</h2>

<!-- #docregion event-binding-1 -->
<button (click)="onSave()">Save</button>
<!-- #enddocregion event-binding-1 -->

<!-- #docregion event-binding-2 -->
<button on-click="onSave()">On Save</button>
<!-- #enddocregion event-binding-2 -->

<div>
<!-- #docregion event-binding-3 -->
<!-- `myClick` is an event on the custom `MyClickDirective` -->

<!-- #docregion my-click -->
<div myClick (myClick)="clickity=$event">click with myClick</div>
<!-- #enddocregion my-click -->
<!-- #enddocregion event-binding-3 -->
{{clickity}}
</div>


<!-- binding to a nested component -->
<!-- #docregion event-binding-to-component -->
<hero-detail (deleted)="onHeroDeleted($event)" [hero]="currentHero">
</hero-detail>
<!-- #enddocregion event-binding-to-component -->
<br>

<big-hero-detail
    (deleted)="onHeroDeleted($event)"
    [hero]="currentHero">
</big-hero-detail>

<!-- #docregion event-binding-bubbling -->
<div class="parent-div" (click)="onClickMe($event)">Click me
  <div class="child-div">Click me too!</div>
</div>
<!-- #enddocregion event-binding-bubbling -->
<br><br>

<!-- #docregion event-binding-no-propagation -->
<!-- Will save only once -->
<div (click)="onSave()">
  <button (click)="onSave()">Save, no propagation</button>
</div>
<!-- #enddocregion event-binding-no-propagation -->
<br><br>
<!-- #docregion event-binding-propagation -->
<!-- Will save twice -->
<div (click)="onSave()">
  <button (click)="onSave() || true">Save w/ propagation</button>
</div>
<!-- #enddocregion event-binding-propagation -->
<br><br>


<!-- Two way data binding unwound;
    passing the changed display value to the event handler via `$event` -->
<hr><h2>NgModel Binding</h2>

<h3>Result: {{currentHero.firstName}}</h3>

<!-- #docregion without-NgModel -->
<input [value]="currentHero.firstName"
       (input)="currentHero.firstName=$event.target.value" >
<!-- #enddocregion without-NgModel -->
without NgModel
<br>
<!-- #docregion NgModel-1 -->
<input [(ngModel)]="currentHero.firstName">
<!-- #enddocregion NgModel-1 -->
[(ngModel)]
<br>
<!-- #docregion NgModel-2 -->
<input bindon-ngModel="currentHero.firstName">
<!-- #enddocregion NgModel-2 -->
bindon-ngModel
<br>
<!-- #docregion NgModel-3 -->
<input
    [ngModel]="currentHero.firstName"
    (ngModelChange)="currentHero.firstName=$event">
<!-- #enddocregion NgModel-3 -->
(ngModelChange) = "...firstName=$event"
<br>
<!-- #docregion NgModel-4 -->
<input
    [ngModel]="currentHero.firstName"
    (ngModelChange)="setUpperCaseFirstName($event)">
<!-- #enddocregion NgModel-4 -->
(ngModelChange) = "setUpperCaseFirstName($event)"
<br>



<!-- NgClass binding -->
<hr><h2>NgClass Binding</h2>

<p>setClasses returns {{setClasses() | json}}</p>
<!-- #docregion NgClass-1 -->
<div [ngClass]="setClasses()">This div is saveable and special</div>
<!-- #enddocregion NgClass-1 -->
<div [ngClass]="setClasses()" #classDiv>
  After setClasses(), the classes are "{{classDiv.className}}"
</div>

<!-- not used in chapter -->

<div [ngClass]="isSpecial ? 'special' : ''">This div is special</div>

<div class="bad curly special">Bad curly special</div>
<div [ngClass]="{bad:false, curly:true, special:true}">Curly special</div>


<!-- NgStyle binding -->
<hr><h2>NgStyle Binding</h2>

<!-- #docregion NgStyle-1 -->
<div [style.font-size]="isSpecial ? 'x-large' : 'smaller'" >
  This div is x-large
</div>
<!-- #enddocregion NgStyle-1 -->

<h3>Use setStyles() - CSS property names</h3>
<p>setStyles returns {{setStyles() | json}}</p>
<!-- #docregion NgStyle-2 -->
<div [ngStyle]="setStyles()">
  This div is italic, normal weight, and x-large
</div>
<!-- #enddocregion NgStyle-2 -->
<div [ngStyle]="setStyles()" #styleDiv>
  After setStyles(), the styles are "{{getStyles(styleDiv)}}"
</div>


<h3>Use setStyles2() - camelCase style property names</h3>
<p>setStyles2 returns {{setStyles2() | json}}</p>
<!-- #docregion NgStyle-3 -->
<div [ngStyle]="setStyles2()">
  This div is italic, normal weight, and x-large
</div>
<!-- #enddocregion NgStyle-3 -->
<div [ngStyle]="setStyles2()" #styleDiv2>
  After setStyles2(), the styles are "{{getStyles(styleDiv2)}}"
</div>

<!-- not used in chapter -->



<!-- NgIf binding -->
<hr><h2>NgIf Binding</h2>

<!-- #docregion NgIf-1 -->
<div *ngIf="currentHero != null">Hello, {{currentHero.firstName}}</div>
<!-- #enddocregion NgIf-1 -->

<!-- #docregion NgIf-2 -->
<!-- not displayed because nullHero is falsey.
    `nullHero.firstName` never has a chance to fail -->
<div *ngIf="nullHero != null">Hello, {{nullHero.firstName}}</div>

<!-- Hero Detail is not in the DOM because isActive is false-->
<hero-detail *ngIf="isActive"></hero-detail>
<!-- #enddocregion NgIf-2 -->


<!-- NgIf binding with template (no *) -->

<template [ngIf]="currentHero != null">Add {{currentHero.firstName}} with template</template>

<!-- Does not show because isActive is false! -->
<div>Hero Detail removed from DOM (via template) because isActive is false</div>
<template [ngIf]="isActive">
  <hero-detail></hero-detail>
</template>

<!-- #docregion NgIf-3 -->
<!-- isSpecial is true -->
<div [class.hidden]="!isSpecial">Show with class</div>
<div [class.hidden]="isSpecial">Hide with class</div>

<!-- HeroDetail is in the DOM but hidden -->
<hero-detail [class.hidden]="isSpecial"></hero-detail>

<div [style.display]="isSpecial ? 'block' : 'none'">Show with style</div>
<div [style.display]="isSpecial ? 'none'  : 'block'">Hide with style</div>
<!-- #enddocregion NgIf-3 -->



<!-- NgSwitch binding -->
<hr><h2>NgSwitch Binding</h2>

<fieldset #toePicker (click)="toeChooser(toePicker)" >
  <input type="radio" name="toes" value="Eenie">Eenie
  <input type="radio" name="toes" value="Meanie">Meanie
  <input type="radio" name="toes" value="Miney">Miney
  <input type="radio" name="toes" value="Moe">Moe
  <input type="radio" name="toes" value="???">???
</fieldset>

<div class="toe">
  <div *ngIf="chosenToe == null">Pick a toe</div>
  <div *ngIf="chosenToe != null">You picked
	  <!-- #docregion NgSwitch -->
	  <span [ngSwitch]="chosenToe">
	    <template [ngSwitchWhen]="'Eenie'">Eenie</template>
	    <template [ngSwitchWhen]="'Meanie'">Meanie</template>
	    <template [ngSwitchWhen]="'Miney'">Miney</template>
	    <template [ngSwitchWhen]="'Moe'">Moe</template>
	    <template ngSwitchDefault>Other</template>
	  </span>
	  <!-- #enddocregion NgSwitch -->
  </div>

</div>

<!-- NgFor binding -->
<hr><h2>NgFor Binding</h2>

<div class="box">
  <!-- #docregion NgFor-1 -->
  <div *ngFor="#hero of heroes">{{hero.fullName}}</div>
  <!-- #enddocregion NgFor-1 -->
</div>
<br>

<div class="box">
  <!-- *ngFor w/ hero-detail Component -->
  <!-- #docregion NgFor-2 -->
  <hero-detail *ngFor="#hero of heroes" [hero]="hero"></hero-detail>
  <!-- #enddocregion NgFor-2 -->
</div>
<br>

<div class="box">
  <!-- #docregion NgFor-3 -->
  <!-- Ex: 1 - Hercules Son of Zeus -->
  <div *ngFor="#hero of heroes, #i=index">{{i + 1}} - {{hero.fullName}}</div>
  <!-- #enddocregion NgFor-3 -->
</div>
<br>

<!-- * and template -->
<hr><h2>* and Template</h2>

<h3>NgIf expansion</h3>
<!-- #docregion Template-1 -->
<hero-detail *ngIf="currentHero != null" [hero]="currentHero"></hero-detail>
<!-- #enddocregion Template-1 -->

<!-- #docregion Template-2 -->
<template [ngIf]="currentHero != null">
    <hero-detail [hero]="currentHero"></hero-detail>
</template>
<!-- #enddocregion Template-2 -->

<h3>NgFor expansion</h3>
<div class="box">
  <!-- ngFor w/ hero-detail Component and a template "attribute" directive -->
  <!-- #docregion Template-3 -->
  <hero-detail template="ngFor #hero of heroes" [hero]="hero"></hero-detail>
  <!-- #enddocregion Template-3 -->
</div>
<br>

<div class="box">
  <!-- ngFor w/ hero-detail Component inside a template element -->
  <!-- #docregion Template-4 -->
  <template ngFor #hero [ngForOf]="heroes">
      <hero-detail [hero]="hero"></hero-detail>
  </template>
  <!-- #enddocregion Template-4 -->
</div>



<!-- template local variable -->
<hr><h2>Template local variables</h2>

<!-- #docregion var-phone -->
<!-- phone refers to the input element; pass its `value` to an event handler -->
<input #phone placeholder="phone number">
<button (click)="callPhone(phone.value)">Call</button>

<!-- fax refers to the input element; pass its `value` to an event handler -->
<input var-fax placeholder="phone number">
<button (click)="callFax(fax.value)">Fax</button>
<!-- #enddocregion var-phone -->

<h4>Example Form</h4>
<!-- #docregion var-form -->
<!-- #docregion var-form-a -->
<form (ngSubmit)="onSubmit(theForm)" #theForm="ngForm">
<!-- #enddocregion var-form-a -->
  <div class="form-group">
    <label for="name">Name</label>
    <input id="name" class="form-control" required ngControl="firstName"
        [(ngModel)]="currentHero.firstName">
  </div>
  <!-- #docregion var-form-a -->
  <button type="submit" [disabled]="!theForm.form.valid">Submit</button>
</form>
<!-- #enddocregion var-form-a -->
<!-- #enddocregion var-form -->
<br><br>

<!-- btn refers to the button element; show its disabled state -->
<button #btn disabled [textContent]="'disabled by attribute: ' + btn.disabled.toString()"></button>

<!-- inputs and output -->
<hr><h2>Inputs and Outputs</h2>

<!-- #docregion io-1 -->
<img [src]="iconUrl"/>
<button (click)="onSave()">Save</button>
<!-- #enddocregion io-1 -->

<!-- #docregion io-2 -->
<hero-detail [hero]="currentHero" (deleted)="onHeroDeleted($event)">
</hero-detail>
<!-- #enddocregion io-2 -->

<!-- <div myClick2 (myClick)="clicked2=$event">myClick2</div>
{{clicked2}}
PENDING: I don't see clicked2 defined anywhere in the TS example
-->

<!-- Pipes -->
<hr><h2>Pipes</h2>

<!-- #docregion pipes-1 -->
<!-- Force title to uppercase -->
<div>{{ title | uppercase }}</div>
<!-- #enddocregion pipes-1 -->

<!-- #docregion pipes-2 -->
<!-- Pipe chaining: force title to uppercase, then to lowercase -->
<div>{{ title | uppercase | lowercase }}</div>
<!-- #enddocregion pipes-2 -->

<!-- #docregion pipes-3 -->
<!-- pipe with configuration argument => "February 25, 1970" -->
<div>Birthdate: {{currentHero?.birthdate | date:'longDate'}}</div>
<!-- #enddocregion pipes-3 -->

<!-- #docregion pipes-json -->
<!--<div>{{currentHero | json}}</div>--> <!-- PENDING: uncomment? -->

<!-- Output:
  { "firstName": "Hercules", "lastName": "Son of Zeus",
    "birthdate": "1970-02-25T08:00:00.000Z",
    "url": "http://www.imdb.com/title/tt0065832/",
    "rate": 325, "id": 1 }
-->
<!-- #enddocregion pipes-json -->


<div>Birthdate: {{(currentHero?.birthdate | date:'longDate') | uppercase}}</div>

<div>
  <!-- pipe price to USD and display the $ symbol -->
  <!--<label>Price: </label>{{product.price | currency:'USD':true}}--> <!-- PENDING: uncomment? -->
</div>


<!-- Null values and the Elvis operator -->
<hr><h2>Elvis</h2>

<div>
  <!-- #docregion elvis-1 -->
  The title is {{ title }}
  <!-- #enddocregion elvis-1 -->
</div>

<div>
  <!-- #docregion elvis-2 -->
  The current hero's name is {{currentHero?.firstName}}
  <!-- #enddocregion elvis-2 -->
</div>

<div>
  <!-- #docregion elvis-3 -->
  The current hero's name is {{currentHero.firstName}}
  <!-- #enddocregion elvis-3 -->
</div>


<!--
The null hero's name is {{nullHero.firstName}}

See console log
          TypeError: Cannot read property 'firstName' of null in [null]
-->

<!-- #docregion elvis-4 -->
<!--No hero, div not displayed, no error -->
<div *ngIf="nullHero != null">The null hero's name is {{nullHero.firstName}}</div>
<!-- #enddocregion elvis-4 -->

<div>
  <!-- #docregion elvis-5 -->
  The null hero's name is {{nullHero != null && nullHero.firstName != null}} <!-- PENDING: ??? -->
  <!-- #enddocregion elvis-5 -->
</div>

<div>
  <!-- #docregion elvis-6 -->
  <!-- No hero, no problem! -->
  The null hero's name is {{nullHero?.firstName}}
  <!-- #enddocregion elvis-6 -->
</div>


<!-- Todo: discuss this in the Style binding section -->
<!-- enums in bindings -->
<hr><h2>Enums in binding</h2>

<p>The name of the Color.Red enum is {{color}}</p> <!-- PENDING: Color[Color.Red]?? -->
<p>The current color number is {{color}}</p>
<p><button [style.color]="color" (click)="colorToggle()">Enum Toggle</button> <!-- PENDING: color -> Color[color]? -->