title: Angular2 attribute directive Hostbinding to host attribute
body: <p>I have a &quot;bootstrapModal&quot; attribute directive that adds bootstrap attributes to the host element:</p>
  <pre><code>data-placement=&quot;top&quot; data-toggle=&quot;modal&quot; data-target=&quot;#DefaultModalWindow&quot;
  </code></pre>
  <p>Is it possible to <code>HostBinding</code> to an attribute like this?</p>
  <pre><code>&lt;htmltag ... bootstrapModal placement=&quot;left&quot;&gt;
  </code></pre>
  <p>And in the directive have something like that:</p>
  <pre><code> @HostBinding('attributes.data-placement') // &lt;== this don't work
   @Input() placement:string='top';
  </code></pre>
  <p>So the result should be:</p>
  <pre><code>&lt;htmltag ... data-placement=&quot;left&quot; data-toggle=&quot;modal&quot; data-target=&quot;#DefaultModalWindow&quot;&gt;
  </code></pre>