import { Directive , ElementRef , HostListener , Input } from "@angular/core" ; @ Directive ( { selector : "[appFallbackSrc]" , } ) export class FallbackSrcDirective { @ Input ( "appFallbackSrc" ) appFallbackSrc : string ; constructor ( private el ) { } @ HostListener ( "error" ) onError ( ) { this . el . nativeElement . src = this . appFallbackSrc ; } }