jQuery.XDomainRequest.js

// jQuery.XDomainRequest.js
// Author: Jason Moon - @JSONMOON
// IE8+
(function($){

if (!$.support.cors && $.ajaxTransport && window.XDomainRequest) {
  var httpRegEx = /^https?:\/\//i;
  var getOrPostRegEx = /^get|post$/i;
  var sameSchemeRegEx = new RegExp('^'+location.protocol, 'i');
  var htmlRegEx = /text\/html/i;
  var jsonRegEx = /\/json/i;
  var xmlRegEx = /\/xml/i;
  
  // ajaxTransport exists in jQuery 1.5+
  $.ajaxTransport('* text html xml json', function(options, userOptions, jqXHR){
    // XDomainRequests must be: asynchronous, GET or POST methods, HTTP or HTTPS protocol, and same scheme as calling page
    if (options.crossDomain && options.async && getOrPostRegEx.test(options.type) && httpRegEx.test(options.url) && sameSchemeRegEx.test(options.url)) {
      var xdr = null;
      var userType = (userOptions.dataType||'').toLowerCase();
      return {
        send: function(headers, complete){
          xdr = new XDomainRequest();
          if (/^\d+$/.test(userOptions.timeout)) {
            xdr.timeout = userOptions.timeout;
          }
          xdr.ontimeout = function(){
            complete(500, 'timeout');
          };
          xdr.onload = function(){
            var allResponseHeaders = 'Content-Length: ' + xdr.responseText.length + '\r\nContent-Type: ' + xdr.contentType;
            var status = {
              code: 200,
              message: 'success'
            };
            var responses = {
              text: xdr.responseText
            };
            try {
              if (userType === 'html' || htmlRegEx.test(xdr.contentType)) {
                responses.html = xdr.responseText;
              } else if (userType === 'json' || (userType !== 'text' && jsonRegEx.test(xdr.contentType))) {
                try {
                  responses.json = $.parseJSON(xdr.responseText);
                } catch(e) {
                  status.code = 500;
                  status.message = 'parseerror';
                  //throw 'Invalid JSON: ' + xdr.responseText;
                }
              } else if (userType === 'xml' || (userType !== 'text' && xmlRegEx.test(xdr.contentType))) {
                var doc = new ActiveXObject('Microsoft.XMLDOM');
                doc.async = false;
                try {
                  doc.loadXML(xdr.responseText);
                } catch(e) {
                  doc = undefined;
                }
                if (!doc || !doc.documentElement || doc.getElementsByTagName('parsererror').length) {
                  status.code = 500;
                  status.message = 'parseerror';
                  throw 'Invalid XML: ' + xdr.responseText;
                }
                responses.xml = doc;
              }
            } catch(parseMessage) {
              throw parseMessage;
            } finally {
              complete(status.code, status.message, responses, allResponseHeaders);
            }
          };
          // set an empty handler for 'onprogress' so requests don't get aborted
          xdr.onprogress = function(){};
          xdr.onerror = function(){
            complete(500, 'error', {
              text: xdr.responseText
            });
          };
          var postData = '';
          if (userOptions.data) {
            postData = ($.type(userOptions.data) === 'string') ? userOptions.data : $.param(userOptions.data);
          }
          xdr.open(options.type, options.url);
          xdr.send(postData);
        },
        abort: function(){
          if (xdr) {
            xdr.abort();
          }
        }
      };
    }
  });
}

})(jQuery);