title: angularjs : @mention in textarea
body: <p>I want to display an autocomplete form triggered by the word <code>@</code> in my textarea like this library <a href="http://ichord.github.io/At.js/">http://ichord.github.io/At.js/</a> but only using angularjs &amp; css</p>
  
  <p>What kind of directive should I write ? Also, is there a way to implement this with the angular bootstrap UI typehead directive ?</p>