Angular2 tutorial学习笔记

import {Component} from 'angular2/core';

interface Hero {
  id: number;
  name: string;
}

@Component({
  selector: 'my-app',
  template: `
    
{{title}}
    
My Heroes
    

      

        {{hero.id}} {{hero.name}}
      
    
    `,
  styles:[`
    .selected {
      background-color: #CFD8DC !important;
      color: white;
    }
    .heroes {
      margin: 0 0 2em 0;
      list-style-type: none;
      padding: 0;
      width: 10em;
    }
    .heroes li {
      cursor: pointer;
      position: relative;
      left: 0;
      background-color: #EEE;
      margin: .5em;
      padding: .3em 0em;
      height: 1.6em;
      border-radius: 4px;
    }
    .heroes li.selected:hover {
      color: white;
    }
    .heroes li:hover {
      color: #607D8B;
      background-color: #EEE;
      left: .1em;
    }
    .heroes .text {
      position: relative;
      top: -3px;
    }
    .heroes .badge {
      display: inline-block;
      font-size: small;
      color: white;
      padding: 0.8em 0.7em 0em 0.7em;
      background-color: #607D8B;
      line-height: 1em;
      position: relative;
      left: -1px;
      top: -4px;
      height: 1.8em;
      margin-right: .8em;
      border-radius: 4px 0px 0px 4px;
    }
  `]
})

export class AppComponent {
  public title = 'Tour of Heroes';
  public heroes = HEROES;
}

var HEROES: Hero[] = [
  { "id": 11, "name": "Mr. Nice" },
  { "id": 12, "name": "Narco" },
  { "id": 13, "name": "Bombasto" },
  { "id": 14, "name": "Celeritas" },
  { "id": 15, "name": "Magneta" },
  { "id": 16, "name": "RubberMan" },
  { "id": 17, "name": "Dynama" },
  { "id": 18, "name": "Dr IQ" },
  { "id": 19, "name": "Magma" },
  { "id": 20, "name": "Tornado" }
];

Interface or Class?

Why a Hero interface and not a Hero class? We want a strongly typed Hero. We get strong typing with either option. Our choice depends on how we intend to use the Hero.

If we need a Hero that goes beyond simple properties, a Hero with logic and behavior, we must define a class. If we only need type checking, the interface is sufficient and lighter weight.

Lighter weight? Transpiling a class to JavaScript produces code. Transpiling an interface produces — nothing. If the class does nothing (and there is nothing for a Hero class to do right now), we prefer an interface.

one-way binding

two-way binding

Listing heroes with ngFor

The (*) prefix to ngFor indicates that the

element and its children constitute a master template.

The ngFor directive iterates over the heroes array returned by the AppComponent.heroes property and stamps out instances of this template.

The quoted text assigned to ngFor means “take each hero in the heroes array, store it in the local hero variable, and make it available to the corresponding template instance”.

The # prefix before "hero" identifies the hero as a local template variable. We can reference this variable within the template to access a hero’s properties.

The Hero Editor
Master/Detail