title: wordpress call to undefine function
body: <p>On event I am loading a file in a page which should include a shortcode for a chat. The issue is that it says call to an undefined function. The shortcode is working fine on the same page, but when is loaded from a different file (same directory) it doesn't work. </p>
  
  <p>I tried this:</p>
  
  <pre><code>&lt;?php 
  $file="/web/htdocs/.../home/wp-content/plugins/quick-chat";
  plugin_dir_url($file); ?&gt;
  </code></pre>
  
  <p>But it doesn't work...</p>