如何在angular 6中使用自定义指令渲染动态生成的嵌入式SVG

@Directive({
  selector: '[appRxnToImage]'
})
export class RxnToImageDirective implements OnInit {
  @Input()
  set appRxnToImage(rxnString: any) {
    this.generateImageFromRxn(rxnString);
  }

  constructor(
    private templateRef: TemplateRef<any>,
    private viewContainerRef: ViewContainerRef,
    private renderer: Renderer2,
    private el: ElementRef
  ) {}
  ngOnInit() {

  }
  private generateImageFromRxn(rxn) {
    // custom method that generated inline svg dynamicaaly 
    MarvinJSUtil.getPackage('#marvinjs-iframe').then(marvinNameSpace => {
      marvin = marvinNameSpace;
      const exporter = customMethodThatCreatesExporter;
      exporter.render(rxn).then(
        svg => {
          // once svg generated i will call applySvg method to render svg
          this.applySvg(svg);
        },
        error => {
          alert(error);
        }
      );
    });
  }
  private applySvg(svg) {
    this.templateRef.elementRef.nativeElement.innerHTML = svg;
    this.viewContainerRef.createEmbeddedView(this.templateRef);
  }

}