Function createHttpBackend

tools/ngui/static/js/lib/angular.js:9246–9361

($browser, XHR, $browserDefer, callbacks, rawDocument, locationProtocol)

}

function createHttpBackend($browser, XHR, $browserDefer, callbacks, rawDocument, locationProtocol) {
  // TODO(vojta): fix the signature
  return function(method, url, post, callback, headers, timeout, withCredentials) {
    $browser.$$incOutstandingRequestCount();
    url = url || $browser.url();

    if (lowercase(method) == 'jsonp') {
      var callbackId = '_' + (callbacks.counter++).toString(36);
      callbacks[callbackId] = function(data) {
        callbacks[callbackId].data = data;
      };

      jsonpReq(url.replace('JSON_CALLBACK', 'angular.callbacks.' + callbackId),
          function() {
        if (callbacks[callbackId].data) {
          completeRequest(callback, 200, callbacks[callbackId].data);
        } else {
          completeRequest(callback, -2);
        }
        delete callbacks[callbackId];
      });
    } else {
      var xhr = new XHR();
      xhr.open(method, url, true);
      forEach(headers, function(value, key) {
        if (value) xhr.setRequestHeader(key, value);
      });

      var status;

      // In IE6 and 7, this might be called synchronously when xhr.send below is called and the
      // response is in the cache. the promise api will ensure that to the app code the api is
      // always async
      xhr.onreadystatechange = function() {
        if (xhr.readyState == 4) {
          var responseHeaders = xhr.getAllResponseHeaders();

          // TODO(vojta): remove once Firefox 21 gets released.
          // begin: workaround to overcome Firefox CORS http response headers bug
          // https://bugzilla.mozilla.org/show_bug.cgi?id=608735
          // Firefox already patched in nightly. Should land in Firefox 21.

          // CORS "simple response headers" http://www.w3.org/TR/cors/
          var value,
              simpleHeaders = ["Cache-Control", "Content-Language", "Content-Type",
                                  "Expires", "Last-Modified", "Pragma"];
          if (!responseHeaders) {
            responseHeaders = "";
            forEach(simpleHeaders, function (header) {
              var value = xhr.getResponseHeader(header);
              if (value) {
                  responseHeaders += header + ": " + value + "\n";
              }
            });
          }
          // end of the workaround.

          completeRequest(callback, status || xhr.status, xhr.responseText,