<!DOCTYPE html>
<html>
<head>
<base href="." />
<title>angular2 playground</title>
<link rel="stylesheet" href="style.css" />
<script src="https://unpkg.com/zone.js/dist/zone.js"></script>
<script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
<script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
<script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
<script src="config.js"></script>
<script>
System.import('app')
.catch(console.error.bind(console));
</script>
</head>
<body>
<my-app>
loading...
</my-app>
</body>
</html>
/* Styles go here */
### Fine Grained Change Detection - Demo 3
Check out the according blog post:
[http://juristr.com/blog/2016/04/angular2-change-detection/](http://juristr.com/blog/2016/04/angular2-change-detection/)
System.config({
//use typescript for compilation
transpiler: 'typescript',
//typescript compiler options
typescriptOptions: {
emitDecoratorMetadata: true
},
paths: {
'npm:': 'https://unpkg.com/'
},
//map tells the System loader where to look for things
map: {
'app': './src',
'@angular/core': 'npm:@angular/core/bundles/core.umd.js',
'@angular/common': 'npm:@angular/common/bundles/common.umd.js',
'@angular/compiler': 'npm:@angular/compiler/bundles/compiler.umd.js',
'@angular/platform-browser': 'npm:@angular/platform-browser/bundles/platform-browser.umd.js',
'@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic.umd.js',
'@angular/http': 'npm:@angular/http/bundles/http.umd.js',
'@angular/router': 'npm:@angular/router/bundles/router.umd.js',
'@angular/forms': 'npm:@angular/forms/bundles/forms.umd.js',
'@angular/core/testing': 'npm:@angular/core/bundles/core-testing.umd.js',
'@angular/common/testing': 'npm:@angular/common/bundles/common-testing.umd.js',
'@angular/compiler/testing': 'npm:@angular/compiler/bundles/compiler-testing.umd.js',
'@angular/platform-browser/testing': 'npm:@angular/platform-browser/bundles/platform-browser-testing.umd.js',
'@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
'@angular/http/testing': 'npm:@angular/http/bundles/http-testing.umd.js',
'@angular/router/testing': 'npm:@angular/router/bundles/router-testing.umd.js',
'rxjs': 'npm:rxjs',
'typescript': 'npm:typescript@2.0.2/lib/typescript.js'
},
//packages defines our app package
packages: {
app: {
main: './main.ts',
defaultExtension: 'ts'
},
rxjs: {
defaultExtension: 'js'
}
}
});
//main entry point
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {AppModule} from './app';
platformBrowserDynamic().bootstrapModule(AppModule)
//our root app component
import {NgModule} from '@angular/core'
import {BrowserModule} from '@angular/platform-browser'
import {Component, Input, DoCheck, KeyValueDiffers } from '@angular/core'
@Component({
selector: 'child',
template:`
<h2>Child component</h2>
{{ person.name }}
`
})
class ChildComponent implements DoCheck {
@Input() person: any;
differ: any;
constructor(private differs: KeyValueDiffers){
this.differ = differs.find({}).create(null);
}
ngOnChanges(changes: {[propName: string]: SimpleChange}) {
console.log('onChanges - person = ', changes['person'].currentValue);
}
ngDoCheck() {
var changes = this.differ.diff(this.person);
if(changes) {
console.log('changes detected');
changes.forEachChangedItem(r => console.log('changed ', r.currentValue));
changes.forEachAddedItem(r => console.log('added ' + r.currentValue));
changes.forEachRemovedItem(r => console.log('removed ' + r.currentValue));
} else {
console.log('nothing changed');
}
}
}
@Component({
selector: 'my-app',
providers: [],
template: `
<div>
<h1>Parent</h1>
<button (click)="changePerson()">change name</button>
<child [person]="person"></child>
</div>
`
})
class App {
private person: any;
constructor() {
this.person = {
name: 'Juri'
}
}
changePerson() {
// ngOnChanges doesn't fire on child components when
// changing mutable objects...only when the obj ref changes..
this.person.name = 'Thomas';
this.person.age = 26;
// this.person = { name: 'Thomas' };
}
}
@NgModule({
imports: [ BrowserModule ],
declarations: [ App, ChildComponent ],
bootstrap: [ App ]
})
export class AppModule {}