import { HostBinding , Input } from "@angular/core" ; export abstract class MultipleClassesBaseDirective { protected _elementClass : string [ ] = [ ] ; @ Input ( 'class' ) @ HostBinding ( 'class' ) get elementClass ( ) : string { return this . _elementClass . join ( ' ' ) ; } set ( val ) { this . _elementClass = val . split ( ' ' ) ; } }