54 lines
2.1 KiB
TypeScript
54 lines
2.1 KiB
TypeScript
import {ElementRef, Component, Directive, View, Injectable, Renderer} from 'angular2/angular2';
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// A service available to the Injector, used by the HelloCmp component.
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@Injectable()
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class GreetingService {
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greeting: string = 'hello';
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}
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// Directives are light-weight. They don't allow new
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// expression contexts (use @Component for those needs).
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@Directive({selector: '[red]'})
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class RedDec {
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// ElementRef is always injectable and it wraps the element on which the
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// directive was found by the compiler.
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constructor(el: ElementRef, renderer: Renderer) { renderer.setElementStyle(el, 'color', 'red'); }
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// constructor(renderer: Renderer) {}
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}
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// Angular 2.0 supports 2 basic types of directives:
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// - Component - the basic building blocks of Angular 2.0 apps. Backed by
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// ShadowDom.(http://www.html5rocks.com/en/tutorials/webcomponents/shadowdom/)
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// - Directive - add behavior to existing elements.
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// @Component is AtScript syntax to annotate the HelloCmp class as an Angular
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// 2.0 component.
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@Component({
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// The Selector prop tells Angular on which elements to instantiate this
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// class. The syntax supported is a basic subset of CSS selectors, for example
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// 'element', '[attr]', [attr=foo]', etc.
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selector: 'hello-app',
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// These are services that would be created if a class in the component's
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// template tries to inject them.
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viewInjector: [GreetingService]
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})
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// The template for the component.
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@View({
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// Expressions in the template (like {{greeting}}) are evaluated in the
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// context of the HelloCmp class below.
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template: `<div class="greeting">{{greeting}} <span red>world</span>!</div>
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<button class="changeButton">change greeting</button>`,
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// All directives used in the template need to be specified. This allows for
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// modularity (RedDec can only be used in this template)
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// and better tooling (the template can be invalidated if the attribute is
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// misspelled).
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directives: [RedDec]
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})
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export class HelloCmp {
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greeting: string;
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constructor(service: GreetingService) { this.greeting = service.greeting; }
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changeGreeting(): void { this.greeting = 'howdy'; }
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}
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