@cheatsheetSection Built-in directives @cheatsheetIndex 2 @description {@target js ts}`import {NgIf, ...} from 'angular2/angular2';`{@endtarget} {@target dart}`import 'package:angular2/angular2.dart';`{@endtarget} @cheatsheetItem syntax: `<section *ngIf="showSection">`|`*ngIf` description: Removes or recreates a portion of the DOM tree based on the showSection expression. @cheatsheetItem syntax: `<li *ngFor="#item of list">`|`*ngFor` description: Turns the li element and its contents into a template, and uses that to instantiate a view for each item in list. @cheatsheetItem syntax: `<div [ngSwitch]="conditionExpression"> <template [ngSwitchWhen]="case1Exp">...</template> <template ngSwitchWhen="case2LiteralString">...</template> <template ngSwitchDefault>...</template> </div>`|`[ngSwitch]`|`[ngSwitchWhen]`|`ngSwitchWhen`|`ngSwitchDefault` description: Conditionally swaps the contents of the div by selecting one of the embedded templates based on the current value of conditionExpression. @cheatsheetItem syntax: `<div [ngClass]="{active: isActive, disabled: isDisabled}">`|`[ngClass]` description: Binds the presence of css classes on the element to the truthiness of the associated map values. The right-hand side expression should return {class-name: true/false} map.