Catch outbound links in Google Analytics

outbound_links.js

/** 
 * Safely track outbound links in Google Analytics using jQuery
 */
(function($) {
  "use strict";
  // Wait till the dom has loaded
  $(document).ready(function(){
    
    // Current page host
    var host = window.location.host;
    
    // Click event on <a> tags within the body
    $('body a').click(function(e){
      var link = $(this),
        href = link.attr('href'),
        target = link.attr('target'),
        text = link.text().substring(140);
        
      if (
        e.isDefaultPrevented()      // Link already aborted
        || typeof ga !== 'function' // Google Analytics not (yet) loaded
        || link.length != 1         // Invalid link reference
        || href.length == 0         // Invalid href
        || host == link[0].host     // Internal href
        || target == '_blank'       // Target a new window, not truly outbound
      ) {
        // Abandon course and follow usual click behaviour
        // console.log('Abandoning outbound event for: ' + href);
        return;
      } else {
        // Function to redirect to outbound page
        function redirect() {
          // console.log('Logging event for outbound link to: ' + href);
          window.document.location = href;
        }
  
        // Cancel event and record outbound link
        e.preventDefault();
        ga('send', {
          'hitType': 'event',
          'eventCategory': 'outbound',
          'eventAction': 'link',
          'eventLabel': href + ' - ' + text,
          'hitCallback': redirect
        });
    
        // Redirect after one second if recording takes too long
        setTimeout(redirect, 1000);
      }
    });
  });
})(jQuery);