ajaxListener.js

<script id="gtm-jq-ajax-listen" type="text/javascript">
  (function() {
 
    'use strict';
	var $;
    var n = 0;
    init();
 
    function init(n) {
 
      // Ensure jQuery is available before anything
      if (typeof jQuery !== 'undefined') {
		
        // Define our $ shortcut locally
        $ = jQuery;
        bindToAjax();
 
      // Check for up to 10 seconds
      } else if (n < 20) {
	
        n++;
        setTimeout(init, 500);
 
      }
 
    }
 
    
    function bindToAjax() {
 
      $(document).bind('ajaxSuccess', function(evt, jqXhr, opts) {
 
        var entries = mapEntries(opts.data);
        window.imbaFormData = entries;
        // Create a fake a element for magically simple URL parsing
        var fullUrl = document.createElement('a');
        fullUrl.href = opts.url;
 
        // IE9+ strips the leading slash from a.pathname because who wants to get home on time Friday anyways
        var pathname = fullUrl.pathname[0] === '/' ? fullUrl.pathname : '/' + fullUrl.pathname;
        // Manually remove the leading question mark, if there is one
        var queryString = fullUrl.search[0] === '?' ? fullUrl.search.slice(1) : fullUrl.search;
        // Turn our params and headers into objects for easier reference
        var queryParameters = objMap(queryString, '&', '=', true);
        var headers = objMap(jqXhr.getAllResponseHeaders(), '\n', ':');
 
        // Blindly push to the dataLayer because this fires within GTM
        dataLayer.push({
          'event': 'ajaxSuccess',
          'attributes': {
            // Return empty strings to prevent accidental inheritance of old data
            'type': opts.type || '',
            'url': fullUrl.href || '',
            'queryParameters': queryParameters,
            'entries': entries,
            'pathname': pathname || '',
            'hostname': fullUrl.hostname || '',
            'protocol': fullUrl.protocol || '',
            'fragment': fullUrl.hash || '',
            'statusCode': jqXhr.status || '',
            'statusText': jqXhr.statusText || '',
            'headers': headers,
            'timestamp': evt.timeStamp || '',
            'contentType': opts.contentType || '',
            // Defer to jQuery's handling of the response
            'response': (jqXhr.responseJSON || jqXhr.responseXML || jqXhr.responseText || '')
          }
        });
 
      });
 
    }
 
    function mapEntries(d) {
      var obj = {};
      d.forEach(function(value, key){
        obj[key] = value;
      });

      return obj;
    }
    function objMap(data, delim, spl, decode) {
 
      var obj = {};
 
      // If one of our parameters is missing, return an empty object
      if (!data || !delim || !spl) {
 
        return {};
 
      }
 
      var arr = data.split(delim);
      var i;
 
      if (arr) {
 
        for (i = 0; i < arr.length; i++) {
 
          // If the decode flag is present, URL decode the set
          var item = decode ? decodeURIComponent(arr[i]) : arr[i];
          var pair = item.split(spl);
 
          var key = trim_(pair[0]);
          var value = trim_(pair[1]);
 
          if (key && value) {
 
            obj[key] = value;
 
          }
 
        }
 
      }
 
      return obj;
 
    }
 
    // Basic .trim() polyfill
    function trim_(str) {
 
      if (str) {
 
        return str.replace(/^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g, '');
 
      }
 
    }
 
 
  })();
  /*
   * v0.1.0
   * Created by the Google Analytics consultants at http://lunametrics15.staging.wpengine.com
   * Written by @notdanwilkerson
   * Documentation: http://lunametrics15.staging.wpengine.com/blog/2015/08/27/ajax-event-listener-google-tag-manager/
   * Licensed under the Creative Commons 4.0 Attribution Public License
   */
</script>