doc(example): adds comments to the hello world app.

Explains the basic concepts as seen in the demo app, but it is not a
substitute for proper documentation which will come later.
This commit is contained in:
Rado Kirov 2014-11-20 12:14:02 -08:00
parent 2980eb5b0b
commit 70c38e6260
1 changed files with 32 additions and 0 deletions

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@ -1,10 +1,30 @@
import {bootstrap, Component, Decorator, TemplateConfig, NgElement} from 'core/core';
// Angular 2.0 supports 3 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/)
// - Decorator - add behavior to existing elements.
// - Template - allow for stamping out of a html template (not in this demo).
// @Component is AtScript syntax to annotate the HelloCmp class as an Angular
// 2.0 component.
@Component({
// The Selector prop tells Angular on which elements to instantiate this
// class. The syntax supported is a basic subset of CSS selectors, for example
// 'element', '[attr]', [attr=foo]', etc.
selector: 'hello-app',
// These are services that would be created if a class in the component's
// template tries to inject them.
componentServices: [GreetingService],
template: new TemplateConfig({
// The template for the component.
// Expressions in the template (like {{greeting}}) are evaluated in the
// context of the HelloCmp class below.
inline: `{{greeting}} <span red>world</foo>!`,
// All directives used in the template need to be specified. This allows for
// modularity (RedDec can only be used in this template)
// and better tooling (the template can be invalidated if the attribute is
// misspelled).
directives: [RedDec]
})
})
@ -14,15 +34,20 @@ class HelloCmp {
}
}
// Decorators are light-weight. They don't allow for templates, or new
// expression contexts (use @Component or @Template for those needs).
@Decorator({
selector: '[red]'
})
class RedDec {
// NgElement is always injectable and it wraps the element on which the
// directive was found by the compiler.
constructor(el: NgElement) {
el.domElement.style.color = 'red';
}
}
// A service used by the HelloCmp component.
class GreetingService {
constructor() {
this.greeting = 'hello';
@ -30,5 +55,12 @@ class GreetingService {
}
export function 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);
}