angular-docs-cn/modules_dart/payload/hello_world/web/index.dart

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library hello_world.index;
import "package:angular2/bootstrap.dart" show bootstrap;
import "package:angular2/core.dart"
show ElementRef, Component, Directive, Injectable;
import "package:angular2/render.dart" show Renderer;
main() {
// Bootstrapping only requires specifying a root component.
// The boundary between the Angular application and the rest of the page is
// the shadowDom of this root component.
// The selector of the component passed in is used to find where to insert the
// application.
// You can use the light dom of the <hello-app> tag as temporary content (for
// example 'Loading...') before the application is ready.
bootstrap(HelloCmp);
}
// A service available to the Injector, used by the HelloCmp component.
@Injectable()
class GreetingService {
String greeting = "hello";
}
// Directives are light-weight. They don't allow new
// expression contexts (use @Component for those needs).
@Directive(selector: "[red]")
class RedDec {
// ElementRef is always injectable and it wraps the element on which the
// directive was found by the compiler.
RedDec(ElementRef el, Renderer renderer) {
renderer.setElementStyle(el, "color", "red");
}
}
// Angular 2.0 supports 2 basic types of directives:
// - Component - the basic building blocks of Angular 2.0 apps. Backed by
// ShadowDom.(http://www.html5rocks.com/en/tutorials/webcomponents/shadowdom/)
// - Directive - add behavior to existing elements.
// @Component is AtScript syntax to annotate the HelloCmp class as an Angular
// 2.0 component.
@Component(
selector: "hello-app",
viewProviders: const [GreetingService],
template:
'''<div class="greeting">{{greeting}} <span red>world</span>!</div>
<button class="changeButton" (click)="changeGreeting()">change greeting</button>''',
directives: const [RedDec])
class HelloCmp {
String greeting;
HelloCmp(GreetingService service) {
this.greeting = service.greeting;
}
void changeGreeting() {
this.greeting = "howdy";
}
}