title: bootstrap collapse panel giving strange output in angular2
body: <p>I just want simple collapse panel for search filter in angular2.
  It is pretty simple.but i am not getting what I am missing here...
  It haven't show panel body  on button click but glyphicon changes its behaviour.
  I have set boolean value in code behind so that on click of search button that inside panel body,results in collapse too.
  Please correct me where I am going wrong... 
  thanq in advanced</p>
  
  <pre><code>&lt;div class="panel panel-default"&gt;
      &lt;div class="panel-heading"&gt;
          &lt;h4 class="panel-title"&gt;
              &lt;!--&lt;a data-toggle="collapse" data-target="#collapse1"&gt;
              Collapsible panel&lt;/a&gt;--&gt;
              &lt;button type="button" class="glyphicon"
                      [ngClass]="{'glyphicon-chevron-up': isCollapsedContent , 'glyphicon-chevron-down': !isCollapsedContent }"
                      style="float: right;" data-toggle="collapse" data-target="#collapse1"
                      (click)="isCollapsedContent = !isCollapsedContent"&gt;&lt;/button&gt;
          &lt;/h4&gt;
      &lt;/div&gt;
      &lt;div id="collapse1" class="panel-collapse collapse"&gt;
          &lt;div class="panel-body"&gt;Panel Body&lt;/div&gt;
          &lt;div class="panel-footer"&gt;Panel Footer&lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>