introduction to angular js 2.0
TRANSCRIPT
AngularJS 2.0
Nagaraju SangamAngular Buff @
ADP
Speaker at various Front End Meetups
Me?
Problems with Angular 1.X
Verbose, steep learning curve Different ways to create different things Not an elegant dependency injection Route: No built-in partial view support using ng-route Issues with Scope & child scopes Dirty checking Issues with digest cycles: $scope.apply(); Two way data binding: Max of 2000 bindings. Errors are ignored in templates. jqLite: No direct modification of dom??? dropped in 2.0 Directives supports “EACM” only no way to use selectors. modules : No built-in module loading No inheritance supported for angular modules
Why re-write?
To knock off many old components. i.e. $scope, $rootScope, services, controllers, modules, jqLite etc. To leverage latest ECMA Script standards To leverage modern browser capabilities. Improve many areas with different approaches with past expirience.
What’s new?
Routing
Services
DI
Directives
ES5 & ES6+
Server Side Angular
Change Detection
Web workers
PromisesTesting
Material design
RxJsTypes
Annotations
What’s new?
Angular JS 1.x Angular JS 2.0
Controllervs
$scopeecives
Component Class
Service Simple Class
Angular Modules ES6 Modules
Directive
Transpilers
Converts source code from one programming language to other. ES6 to ES5 Transpilers
Traceur Typescript Flow Babel Dart
Angular2 apps should be written in ES6. since the browsers doesn’t support ES6 you can use any of the above transpiler to convert it to ES5.
Google and Microsoft are working together to make type script as a standard for developing angular2.0 apps.
http://www.2ality.com/2014/10/typed-javascript.html
AtScript vs Type script
ES6
ES5
Type s
Annotations
AtScript Type script
Change Detection
Angular 1.X
Angular 2.0
Change detection happens at DOM node level onlyChange in one node triggers dirty checking at all other nodes.
Change detection can happen at component level as well.Change in one component triggers dirty checking in other nodes below the current node…Change detection strategy can be configured at component level
Change Detection
@Component({ selector: <string>‘,
changeDetection: ‘<string>’
})
@View({ template: ‘<string>’})
export class <className>{ constructor() { }}
The changeDetection property defines, whether the change detection will be checked every time or only when the component tells it to do so.
Watchtower.js is used for change detection.
Routing
Routing happens at component level, for each different route different component can be loaded into RouterOutlet directive, it is similar to ui-view in angular 1.X.
@RouteConfig([ { path: '/', redirectTo: '/sponsers' }, { path: '/sponsers', component: Sponsers, as: 'sponsers'}, //sponsers & attendees are components { path: '/attendees', component: Attendees, as: 'attendees'}])
<router-outlet></router-outlet>
Router-Link is similar to hg-href in 1.X.
<a [router-link]="[\'/attendees\']" router-params="">attendees</a>
JSON based route config 404 support QueryString support Lyfecycle events routeResolver
Directives
Component Directives Decorative Directives Template Directives
Following annotations are used to create directives. @Directive @Component
http://www.2ality.com/2014/10/typed-javascript.html
Services
Service is a simple ES6 class in Angular2, these services should be injected into components via Dependency Injection.
Sponsers-Service.ts
export class SponsersService{ constructor() { } getData(){ return ['cisco','intel','flipkart']; }}
http://www.2ality.com/2014/10/typed-javascript.html
Http
http://www.2ality.com/2014/10/typed-javascript.html
Http is available as a separate module in alpha 35: https://code.angularjs.org/2.0.0-alpha.35
Eg:
import {Http, httpInjectables} from 'angular2/http';@Component({selector: 'http-app', viewBindings: [httpInjectables]})@View({templateUrl: 'people.html'})class PeopleComponent { constructor(http: Http) { http.get('people.json') .toRx() .map(res => res.json()) .subscribe(people => this.people = people); }}
DI
Dependencies can be specifies as parameters: eg: function(@Inject(<svcName>) s) Component dependencies should be listed in bindings property of @Component
annotation. Template dependencies should be listed in directives property of @View annotation.
http://www.2ality.com/2014/10/typed-javascript.html
import {Component, View, Injector} from 'angular2/angular2';import { NgFor } from 'angular2/angular2';import {SponsersService} from 'services/sponsers-service';
@Component({ selector: 'sponsers', bindings:[SponsersService]})
@View({ template: '<ul><li *ng-for="#item of data">{{item}}</li></ul>', directives:[NgFor]})
export class Sponsers { data; constructor(@Inject(SponsersService) s) { this.data = s.getData(); }}
Webworkers…Main-thread
(Browser+App+Angular Dom renderer)
messages
Child thread(Angular stuff – house keeping etc)
References… http://angular.io www.victorsavkin.com www.tryangular2.com http://www.syntaxsuccess.com/viewarticle/routing-in-angular-2.0 http://blog.thoughtram.io/angular/2015/06/16/routing-in-angular-2.html
Thank you…