title: load css stylesheet in twig
body: <p>I'm trying to load a css file depending on who's connected.
  So I've concateneted my url path with the variable, I don't seem to et any erros but the css doesnt show.
  If you've got any advice.</p>
  
  <p>cheers</p>
  
  <p>My code:</p>
  
  <pre><code>&lt;head&gt;
          &lt;meta charset="UTF-8" /&gt;
          &lt;title&gt;{% block title %}{% endblock %}-S...&lt;/title&gt;
          {% block stylesheets %}
              {% stylesheets
                  "@xxxMainBundle/Resources/css/general/*"
              %}
  
              &lt;link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css"&gt;
  
              &lt;!--link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" integrity="sha256-MfvZlkHCEqatNoGiOXveE8FIwMzZg4W85qfrfIFBfYc= sha512-dTfge/zgoMYpP7QbHy4gWMEGsbsdZeCXz7irItjcC3sPUFtf0kuFbDz/ixG7ArTxmDjLXDmezHubeNikyKGVyQ==" crossorigin="anonymous"--&gt;
              {% if (app.session.get('courtierStyle') is defined) and (app.session.get('courtierStyle') is not null) %}
                  {% set varStyle = "Sygedel/MainBundle/Resources/css/courtier/"~ app.session.get('courtierStyle') %} /*I set the var here*/
  
                      &lt;link rel="stylesheet" type="text/css" href="{{ varStyle }}"/&gt; /* and pass it in th elink tag here"
  
              {% endif %}
          {% endblock %}
          &lt;link rel="icon" type="image/x-icon" href="{{ asset('favicon.ico') }}" /&gt;
      &lt;/head&gt;
  </code></pre>