browser/src/app/directives/fallback-src.directive.ts

import {
    Directive,
    ElementRef,
    HostListener,
    Input,
} from '@angular/core';

@Directive({
    selector: '[appFallbackSrc]',
})
export class FallbackSrcDirective {
    @Input('appFallbackSrc') appFallbackSrc: string;

    constructor(private el: ElementRef) {
    }

    @HostListener('error') onError() {
        this.el.nativeElement.src = this.appFallbackSrc;
    }
}