Using a directive to add class to host element
<p>I am currently learning Angular 2. I understood how to use the Angular <code>Renderer</code> to set an <code>ElementStyle</code>, but now I would like to use the <code>Renderer</code> method: </p>

<pre><code>setElementClass(renderElement: any, className: string, isAdd: boolean) : void
</code></pre>

<p>My question is how can I import a CSS class to my attribute directive? 
Do I have to convert my CSS class to JSON?</p>