global.html

<!DOCTYPE html>
<html>
  <head>
    <title>Polr Link Shortener</title>
    <script type="text/javascript">
      function performCommand(event) {
        if (event.command != 'shortenlink') return false;
        
        var url = safari.application.activeBrowserWindow.activeTab.url;
        
        var requestURL = safari.extension.settings.endpoint;
        requestURL += '/api/v2/action/shorten?';
        requestURL += 'key=' + safari.extension.secureSettings.apikey;
        requestURL += '&url=' + encodeURIComponent(url);
        requestURL += '&is_secret=false';
        
        var request = new XMLHttpRequest();
        request.open("GET", requestURL, true);
        request.onreadystatechange = function() {
          if (request.readyState == 4) {
            if (request.status == 200) {
              alert(request.responseText);
            } else {
              alert('Failed to shorten link.');
            }
          }
        }

        request.send();
      }
      
      safari.application.addEventListener('command', performCommand, true);
    </script>
  </head>
  <body>
  </body>
</html>