highlight directive added

app/shared/directives/highlight.directive.ts

@@ -0,0 +1,22 @@
+import { Directive, ElementRef, HostListener, Input, Renderer } from '@angular/core';
+
+@Directive({
+  selector: '[feedHighlight]'
+})
+export class HighlightDirective {
+  constructor(private el: ElementRef, private renderer: Renderer) {
+      this.renderer.setElementClass(this.el.nativeElement, 'feed-highlight', true);
+   }
+
+  @HostListener('mouseenter') onMouseEnter() {
+    this.highlight('white');
+  }
+
+  @HostListener('mouseleave') onMouseLeave() {
+    this.highlight(null);
+  }
+
+  private highlight(color: string) {
+    this.renderer.setElementStyle(this.el.nativeElement, 'backgroundColor', color);
+  }
+}