title: Aurelia Binding Click Trigger in Nav Bar
body: <p>Given the following layout for app.html:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;template&gt;
    &lt;require from="nav-bar.html"&gt;&lt;/require&gt;
    &lt;require from="bootstrap/css/bootstrap.css"&gt;&lt;/require&gt;
  
    &lt;nav-bar router.bind="router"&gt;&lt;/nav-bar&gt;
    &lt;div id="sidebar"&gt;&lt;h3&gt;This is the sidebar.&lt;/h3&gt;&lt;/div&gt;
  
    &lt;div id="page-host" class="page-host"&gt;
      &lt;router-view&gt;&lt;/router-view&gt;
    &lt;/div&gt;
  &lt;/template&gt;
  </code></pre>
  
  <p>How do I bind to the toggleSidebar function (which is exported from app.js) in nav-bar.html?</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;template bindable="router"&gt;
    &lt;nav class="navbar navbar-default navbar-fixed-top" role="navigation"&gt;
      &lt;div class="navbar-header"&gt;
        ....
  
        &lt;a class="navbar-brand" href="#" click.trigger="toggleSidebar()"&gt;
          &lt;i class="fa fa-bars"&gt;&lt;/i&gt;
          &lt;span&gt;${router.title}&lt;/span&gt;
        &lt;/a&gt;
      &lt;/div&gt;
  
      ....
    &lt;/nav&gt;
  &lt;/template&gt;
  </code></pre>
  
  <p>Currently I get the following error when I click on the toggleSidebar link:</p>
  
  <p>"toggleSidebar is not a function". </p>