description

# requestCrossOrigin method Null safety

Future<String> requestCrossOrigin (

1. String url,
2. {String? method,
3. String? sendData}

)

Makes a cross-origin request to the specified URL.

This API provides a subset of request which works on IE9. If IE9 cross-origin support is not required then request should be used instead.

## Implementation

    static Future<String> requestCrossOrigin(String url,
        {String? method, String? sendData}) {
      if (supportsCrossOrigin) {
        return request(url, method: method, sendData: sendData).then((xhr) {
          return xhr.responseText!;
        });
      }
      var completer = new Completer<String>();
      if (method == null) {
        method = 'GET';
      }
      var xhr = JS('var', 'new XDomainRequest()');
      JS('', '#.open(#, #)', xhr, method, url);
      JS(
          '',
          '#.onload = #',
          xhr,
          convertDartClosureToJS((e) {
            var response = JS('String', '#.responseText', xhr);
            completer.complete(response as FutureOr<String>?);
          }, 1));
      JS(
          '',
          '#.onerror = #',
          xhr,
          convertDartClosureToJS((e) {
            completer.completeError(e);
          }, 1));

      // IE9 RTM - XDomainRequest issued requests may abort if all event handlers
      // not specified
      // http://social.msdn.microsoft.com/Forums/ie/en-US/30ef3add-767c-4436-b8a9-f1ca19b4812e/ie9-rtm-xdomainrequest-issued-requests-may-abort-if-all-event-handlers-not-specified
      JS('', '#.onprogress = {}', xhr);
      JS('', '#.ontimeout = {}', xhr);
      JS('', '#.timeout = Number.MAX_VALUE', xhr);

      if (sendData != null) {
        JS('', '#.send(#)', xhr, sendData);
      } else {
        JS('', '#.send()', xhr);
      }

      return completer.future;
    }