import { Directive , ElementRef , Optional , Renderer } from '@angular/core' ; import { Config } from '../../config/config' ; import { Ion } from '../ion' ; import { Footer as IFooter } from '../../navigation/nav-interfaces' ; import { ViewController } from '../../navigation/view-controller' ; name description usage @ Directive ( { selector : 'ion-footer' } ) export class Footer extends Ion implements IFooter { constructor ( config , elementRef , renderer , @ Optional ( ) viewCtrl ) { super ( config , elementRef , renderer , 'footer' ) ; viewCtrl && viewCtrl . _setFooter ( this ) ; } }