title: Disactivating RouterLinkActive attribute conditionally to some value
body: <p>In this simple menu item component:</p>
  
  <pre><code>import { Component, Input } from '@angular/core';
  
  @Component({
    selector: 'nav-item',
    template: `
      &lt;a [routerLink]="routeUrl" 
      routerLinkActive="active-link" 
      &gt;
      &lt;/a&gt;
    `
  })
  
  export class NavItemComponent {
    @Input() routerLinkActiveIsDisabled: boolean;
  }
  </code></pre>
  
  <p>I would like <code>routerLinkActive</code> to be used on only certain items not all.</p>
  
  <p>How can I make it so that the <code>routerLinkActive</code> attribute is removed  if <code>routerLinkActiveIsDisabled</code> is <code>true</code></p>