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dart:html›Classes›HttpRequest

HttpRequest ​

class HttpRequest extends HttpRequestEventTarget

Annotations: @Native.new("XMLHttpRequest")

A client-side XHR request for getting data from a URL, formally known as XMLHttpRequest.

Note: You should avoid directly using HttpRequest to make HTTP requests. You can use HttpRequest indirectly through the BrowserClient adapter in package:http.

Using a higher-level library, like package:http, allows you to switch implementations with minimal changes to your code. For example, package:httpClient has implementations for the browser and implementations that use platform native HTTP clients on Android and iOS.

HttpRequest can be used to obtain data from HTTP and FTP protocols, and is useful for AJAX-style page updates.

The simplest way to get the contents of a text file, such as a JSON-formatted file, is with getString. For example, the following code gets the contents of a JSON file and prints its length:

dart
var path = 'myData.json';
HttpRequest.getString(path).then((String fileContents) {
  print(fileContents.length);
}).catchError((error) {
  print(error.toString());
});

Fetching data from other servers ​

For security reasons, browsers impose restrictions on requests made by embedded apps. With the default behavior of this class, the code making the request must be served from the same origin (domain name, port, and application layer protocol) as the requested resource. In the example above, the myData.json file must be co-located with the app that uses it.

Other resources ​

Inheritance

Object → EventTarget → HttpRequestEventTarget → HttpRequest

Constructors ​

HttpRequest() factory ​

factory HttpRequest()

General constructor for any type of request (GET, POST, etc).

This call is used in conjunction with open:

dart
var request = new HttpRequest();
request.open('GET', 'http://dartlang.org');
request.onLoad.listen((event) => print(
    'Request complete ${event.target.reponseText}'));
request.send();

is the (more verbose) equivalent of

dart
HttpRequest.getString('http://dartlang.org').then(
    (result) => print('Request complete: $result'));
Implementation
dart
factory HttpRequest() {
  return HttpRequest._create_1();
}

Properties ​

hashCode no setter inherited ​

int get hashCode

Inherited from Interceptor.

Implementation
dart
int get hashCode => Primitives.objectHashCode(this);

on no setter inherited ​

Events get on

This is an ease-of-use accessor for event streams which should only be used when an explicit accessor is not available.

Inherited from EventTarget.

Implementation
dart
Events get on => new Events(this);

onAbort no setter inherited ​

Stream<ProgressEvent> get onAbort

Stream of abort events handled by this HttpRequestEventTarget.

Inherited from HttpRequestEventTarget.

Implementation
dart
Stream<ProgressEvent> get onAbort => abortEvent.forTarget(this);

onError no setter inherited ​

Stream<ProgressEvent> get onError

Stream of error events handled by this HttpRequestEventTarget.

Inherited from HttpRequestEventTarget.

Implementation
dart
Stream<ProgressEvent> get onError => errorEvent.forTarget(this);

onLoad no setter inherited ​

Stream<ProgressEvent> get onLoad

Stream of load events handled by this HttpRequestEventTarget.

Inherited from HttpRequestEventTarget.

Implementation
dart
Stream<ProgressEvent> get onLoad => loadEvent.forTarget(this);

onLoadEnd no setter inherited ​

Stream<ProgressEvent> get onLoadEnd

Stream of loadend events handled by this HttpRequestEventTarget.

Inherited from HttpRequestEventTarget.

Implementation
dart
@SupportedBrowser(SupportedBrowser.CHROME)
@SupportedBrowser(SupportedBrowser.FIREFOX)
@SupportedBrowser(SupportedBrowser.IE, '10')
@SupportedBrowser(SupportedBrowser.SAFARI)
Stream<ProgressEvent> get onLoadEnd => loadEndEvent.forTarget(this);

onLoadStart no setter inherited ​

Stream<ProgressEvent> get onLoadStart

Stream of loadstart events handled by this HttpRequestEventTarget.

Inherited from HttpRequestEventTarget.

Implementation
dart
Stream<ProgressEvent> get onLoadStart => loadStartEvent.forTarget(this);

onProgress no setter inherited ​

Stream<ProgressEvent> get onProgress

Stream of progress events handled by this HttpRequestEventTarget.

Inherited from HttpRequestEventTarget.

Implementation
dart
@SupportedBrowser(SupportedBrowser.CHROME)
@SupportedBrowser(SupportedBrowser.FIREFOX)
@SupportedBrowser(SupportedBrowser.IE, '10')
@SupportedBrowser(SupportedBrowser.SAFARI)
Stream<ProgressEvent> get onProgress => progressEvent.forTarget(this);

onReadyStateChange no setter ​

Stream<Event> get onReadyStateChange

Event listeners to be notified every time the HttpRequest object's readyState changes values.

Implementation
dart
Stream<Event> get onReadyStateChange => readyStateChangeEvent.forTarget(this);

onTimeout no setter inherited ​

Stream<ProgressEvent> get onTimeout

Stream of timeout events handled by this HttpRequestEventTarget.

Inherited from HttpRequestEventTarget.

Implementation
dart
Stream<ProgressEvent> get onTimeout => timeoutEvent.forTarget(this);

readyState no setter ​

int get readyState

Indicator of the current state of the request:

ValueStateMeaning
0unsentopen() has not yet been called
1openedsend() has not yet been called
2headers receivedsent() has been called; response headers and status are available
3 loading responseText holds some data
4 done request is complete
Implementation
dart
int get readyState native;

response no setter ​

dynamic get response

The data received as a reponse from the request.

The data could be in the form of a String, ByteBuffer, Document, Blob, or json (also a String). null indicates request failure.

Implementation
dart
@SupportedBrowser(SupportedBrowser.CHROME)
@SupportedBrowser(SupportedBrowser.FIREFOX)
@SupportedBrowser(SupportedBrowser.IE, '10')
@SupportedBrowser(SupportedBrowser.SAFARI)
dynamic get response => _convertNativeToDart_XHR_Response(this._get_response);

responseHeaders no setter ​

Map<String, String> get responseHeaders

Returns all response headers as a key-value map.

Multiple values for the same header key can be combined into one, separated by a comma and a space.

See: http://www.w3.org/TR/XMLHttpRequest/#the-getresponseheader()-method

Implementation
dart
Map<String, String> get responseHeaders {
  &#47;&#47; from Closure's goog.net.Xhrio.getResponseHeaders.
  var headers = <String, String>{};
  var headersString = this.getAllResponseHeaders();
  if (headersString == null) {
    return headers;
  }
  var headersList = headersString.split('\r\n');
  for (var header in headersList) {
    if (header.isEmpty) {
      continue;
    }

    var splitIdx = header.indexOf(': ');
    if (splitIdx == -1) {
      continue;
    }
    var key = header.substring(0, splitIdx).toLowerCase();
    var value = header.substring(splitIdx + 2);
    if (headers.containsKey(key)) {
      headers[key] = '${headers[key]}, $value';
    } else {
      headers[key] = value;
    }
  }
  return headers;
}

responseText no setter ​

String? get responseText

The response in String form or empty String on failure.

Implementation
dart
String? get responseText native;

responseType read / write ​

String get responseType

String telling the server the desired response format.

Default is String. Other options are one of 'arraybuffer', 'blob', 'document', 'json', 'text'. Some newer browsers will throw NS_ERROR_DOM_INVALID_ACCESS_ERR if responseType is set while performing a synchronous request.

See also: MDN responseType

Implementation
dart
String get responseType native;

set responseType(String value) native;

responseUrl no setter ​

String? get responseUrl
Implementation
dart
@JSName('responseURL')
String? get responseUrl native;

responseXml no setter ​

Document? get responseXml

The request response, or null on failure.

The response is processed as text/xml stream, unless responseType = 'document' and the request is synchronous.

Implementation
dart
@JSName('responseXML')
&#47;**
 * The request response, or null on failure.
 *
 * The response is processed as
 * `text&#47;xml` stream, unless responseType = 'document' and the request is
 * synchronous.
 *&#47;
Document? get responseXml native;

runtimeType no setter inherited ​

Type get runtimeType

Inherited from Interceptor.

Implementation
dart
Type get runtimeType =>
    getRuntimeTypeOfInterceptorNotArray(getInterceptor(this), this);

status no setter ​

int? get status

The HTTP result code from the request (200, 404, etc). See also: HTTP Status Codes

Implementation
dart
int? get status native;

statusText no setter ​

String? get statusText

The request response string (such as "OK"). See also: HTTP Status Codes

Implementation
dart
String? get statusText native;

timeout read / write ​

int? get timeout

Length of time in milliseconds before a request is automatically terminated.

When the time has passed, an HttpRequestEventTarget.timeoutEvent is dispatched.

If timeout is set to 0, then the request will not time out.

Other resources ​

Implementation
dart
int? get timeout native;

set timeout(int? value) native;

upload no setter ​

HttpRequestUpload get upload

EventTarget that can hold listeners to track the progress of the request.

Implementation
dart
@Unstable()
HttpRequestUpload get upload native;

withCredentials read / write ​

bool? get withCredentials

True if cross-site requests should use credentials such as cookies or authorization headers; false otherwise.

This value is ignored for same-site requests.

Implementation
dart
bool? get withCredentials native;

set withCredentials(bool? value) native;

Methods ​

abort() ​

void abort()

Stop the current request.

The request can only be stopped if readyState is HEADERS_RECEIVED or LOADING. If this method is not in the process of being sent, the method has no effect.

Implementation
dart
void abort() native;

addEventListener() inherited ​

void addEventListener(
  String type,
  (dynamic Function(Event event))? listener, [
  bool? useCapture,
])

Inherited from EventTarget.

Implementation
dart
void addEventListener(
  String type,
  EventListener? listener, [
  bool? useCapture,
]) {
  &#47;&#47; TODO(leafp): This check is avoid a bug in our dispatch code when
  &#47;&#47; listener is null.  The browser treats this call as a no-op in this
  &#47;&#47; case, so it's fine to short-circuit it, but we should not have to.
  if (listener != null) {
    _addEventListener(type, listener, useCapture);
  }
}

dispatchEvent() inherited ​

bool dispatchEvent(Event event)

Inherited from EventTarget.

Implementation
dart
bool dispatchEvent(Event event) native;

getAllResponseHeaders() ​

String getAllResponseHeaders()

Retrieve all the response headers from a request.

null if no headers have been received. For multipart requests, getAllResponseHeaders will return the response headers for the current part of the request.

See also HTTP response headers for a list of common response headers.

Implementation
dart
@Unstable()
String getAllResponseHeaders() native;

getResponseHeader() ​

String? getResponseHeader(String name)

Return the response header named header, or null if not found.

See also HTTP response headers for a list of common response headers.

Implementation
dart
@Unstable()
String? getResponseHeader(String name) native;

noSuchMethod() inherited ​

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dart
dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

dart
class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Interceptor.

Implementation
dart
dynamic noSuchMethod(Invocation invocation) {
  throw NoSuchMethodError.withInvocation(this, invocation);
}

open() ​

void open(
  String method,
  String url, {
  bool? async,
  String? user,
  String? password,
})

Specify the desired url, and method to use in making the request.

By default the request is done asynchronously, with no user or password authentication information. If async is false, the request will be sent synchronously.

Calling open again on a currently active request is equivalent to calling abort.

Note: Most simple HTTP requests can be accomplished using the getString, request, requestCrossOrigin, or postFormData methods. Use of this open method is intended only for more complex HTTP requests where finer-grained control is needed.

Implementation
dart
void open(
  String method,
  String url, {
  bool? async,
  String? user,
  String? password,
}) native;

overrideMimeType() ​

void overrideMimeType(String mime)

Specify a particular MIME type (such as text/xml) desired for the response.

This value must be set before the request has been sent. See also the list of IANA Official MIME types.

Implementation
dart
@SupportedBrowser(SupportedBrowser.CHROME)
@SupportedBrowser(SupportedBrowser.FIREFOX)
@SupportedBrowser(SupportedBrowser.SAFARI)
void overrideMimeType(String mime) native;

removeEventListener() inherited ​

void removeEventListener(
  String type,
  (dynamic Function(Event event))? listener, [
  bool? useCapture,
])

Inherited from EventTarget.

Implementation
dart
void removeEventListener(
  String type,
  EventListener? listener, [
  bool? useCapture,
]) {
  &#47;&#47; TODO(leafp): This check is avoid a bug in our dispatch code when
  &#47;&#47; listener is null.  The browser treats this call as a no-op in this
  &#47;&#47; case, so it's fine to short-circuit it, but we should not have to.
  if (listener != null) {
    _removeEventListener(type, listener, useCapture);
  }
}

send() ​

void send([dynamic body_OR_data])

Send the request with any given data.

Note: Most simple HTTP requests can be accomplished using the getString, request, requestCrossOrigin, or postFormData methods. Use of this send method is intended only for more complex HTTP requests where finer-grained control is needed.

Other resources ​

Implementation
dart
void send([body_OR_data]) native;

setRequestHeader() ​

void setRequestHeader(String name, String value)

Sets the value of an HTTP request header.

This method should be called after the request is opened, but before the request is sent.

Multiple calls with the same header will combine all their values into a single header.

Other resources ​

Implementation
dart
void setRequestHeader(String name, String value) native;

toString() inherited ​

String toString()

A string representation of this object.

Some classes have a default textual representation, often paired with a static parse function (like int.parse). These classes will provide the textual representation as their string representation.

Other classes have no meaningful textual representation that a program will care about. Such classes will typically override toString to provide useful information when inspecting the object, mainly for debugging or logging.

Inherited from Interceptor.

Implementation
dart
String toString() => Primitives.objectToHumanReadableString(this);

Operators ​

operator ==() inherited ​

bool operator ==(Object other)

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

  • Total: It must return a boolean for all arguments. It should never throw.

  • Reflexive: For all objects o, o == o must be true.

  • Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.

  • Transitive: For all objects o1, o2, and o3, if o1 == o2 and o2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Inherited from Interceptor.

Implementation
dart
bool operator ==(Object other) => identical(this, other);

Static Properties ​

supportsCrossOrigin no setter ​

bool get supportsCrossOrigin

Checks to see if the current platform supports making cross origin requests.

Note that even if cross origin requests are supported, they still may fail if the destination server does not support CORS requests.

Implementation
dart
static bool get supportsCrossOrigin {
  var xhr = new HttpRequest();
  return JS('bool', '("withCredentials" in #)', xhr);
}

supportsLoadEndEvent no setter ​

bool get supportsLoadEndEvent

Checks to see if the LoadEnd event is supported on the current platform.

Implementation
dart
static bool get supportsLoadEndEvent {
  var xhr = new HttpRequest();
  return JS('bool', '("onloadend" in #)', xhr);
}

supportsOverrideMimeType no setter ​

bool get supportsOverrideMimeType

Checks to see if the overrideMimeType method is supported on the current platform.

Implementation
dart
static bool get supportsOverrideMimeType {
  var xhr = new HttpRequest();
  return JS('bool', '("overrideMimeType" in #)', xhr);
}

supportsProgressEvent no setter ​

bool get supportsProgressEvent

Checks to see if the Progress event is supported on the current platform.

Implementation
dart
static bool get supportsProgressEvent {
  var xhr = new HttpRequest();
  return JS('bool', '("onprogress" in #)', xhr);
}

Static Methods ​

getString() ​

Future<String> getString(
  String url, {
  bool? withCredentials,
  (void Function(ProgressEvent e))? onProgress,
})

Creates a GET request for the specified url.

This is similar to request but specialized for HTTP GET requests which return text content.

To add query parameters, append them to the url following a ?, joining each key to its value with = and separating key-value pairs with &.

dart
var name = Uri.encodeQueryComponent('John');
var id = Uri.encodeQueryComponent('42');
HttpRequest.getString('users.json?name=$name&id=$id')
  .then((String resp) {
    // Do something with the response.
});

See also:

Implementation
dart
static Future<String> getString(
  String url, {
  bool? withCredentials,
  void onProgress(ProgressEvent e)?,
}) {
  return request(
    url,
    withCredentials: withCredentials,
    onProgress: onProgress,
  ).then((HttpRequest xhr) => xhr.responseText!);
}

postFormData() ​

Future<HttpRequest> postFormData(
  String url,
  Map<String, String> data, {
  bool? withCredentials,
  String? responseType,
  Map<String, String>? requestHeaders,
  (void Function(ProgressEvent e))? onProgress,
})

Makes a server POST request with the specified data encoded as form data.

This is roughly the POST equivalent of getString. This method is similar to sending a FormData object with broader browser support but limited to String values.

If data is supplied, the key/value pairs are URI encoded with Uri.encodeQueryComponent and converted into an HTTP query string.

Unless otherwise specified, this method appends the following header:

dart
Content-Type: application/x-www-form-urlencoded; charset=UTF-8

Here's an example of using this method:

dart
var data = { 'firstName' : 'John', 'lastName' : 'Doe' };
HttpRequest.postFormData('/send', data).then((HttpRequest resp) {
  // Do something with the response.
});

See also:

Implementation
dart
static Future<HttpRequest> postFormData(
  String url,
  Map<String, String> data, {
  bool? withCredentials,
  String? responseType,
  Map<String, String>? requestHeaders,
  void onProgress(ProgressEvent e)?,
}) {
  var parts = [];
  data.forEach((key, value) {
    parts.add(
      '${Uri.encodeQueryComponent(key)}='
      '${Uri.encodeQueryComponent(value)}',
    );
  });
  var formData = parts.join('&');

  if (requestHeaders == null) {
    requestHeaders = <String, String>{};
  }
  requestHeaders.putIfAbsent(
    'Content-Type',
    () => 'application&#47;x-www-form-urlencoded; charset=UTF-8',
  );

  return request(
    url,
    method: 'POST',
    withCredentials: withCredentials,
    responseType: responseType,
    requestHeaders: requestHeaders,
    sendData: formData,
    onProgress: onProgress,
  );
}

request() ​

Future<HttpRequest> request(
  String url, {
  String? method,
  bool? withCredentials,
  String? responseType,
  String? mimeType,
  Map<String, String>? requestHeaders,
  dynamic sendData,
  (void Function(ProgressEvent e))? onProgress,
})

Creates and sends a URL request for the specified url.

By default request will perform an HTTP GET request, but a different method (POST, PUT, DELETE, etc) can be used by specifying the method parameter. (See also HttpRequest.postFormData for POST requests only.

The Future is completed when the response is available.

If specified, sendData will send data in the form of a ByteBuffer, Blob, Document, String, or FormData along with the HttpRequest.

If specified, responseType sets the desired response format for the request. By default it is String, but can also be 'arraybuffer', 'blob', 'document', 'json', or 'text'. See also HttpRequest.responseType for more information.

The withCredentials parameter specified that credentials such as a cookie (already) set in the header or authorization headers should be specified for the request. Details to keep in mind when using credentials:

  • Using credentials is only useful for cross-origin requests.
  • The Access-Control-Allow-Origin header of url cannot contain a wildcard (*).
  • The Access-Control-Allow-Credentials header of url must be set to true.
  • If Access-Control-Expose-Headers has not been set to true, only a subset of all the response headers will be returned when calling getAllResponseHeaders.

The following is equivalent to the getString sample above:

dart
var name = Uri.encodeQueryComponent('John');
var id = Uri.encodeQueryComponent('42');
HttpRequest.request('users.json?name=$name&id=$id')
  .then((HttpRequest resp) {
    // Do something with the response.
});

Here's an example of submitting an entire form with FormData.

dart
var myForm = querySelector('form#myForm');
var data = new FormData(myForm);
HttpRequest.request('/submit', method: 'POST', sendData: data)
  .then((HttpRequest resp) {
    // Do something with the response.
});

Note that requests for file:// URIs are only supported by Chrome extensions with appropriate permissions in their manifest. Requests to file:// URIs will also never fail- the Future will always complete successfully, even when the file cannot be found.

See also: authorization headers.

Implementation
dart
static Future<HttpRequest> request(
  String url, {
  String? method,
  bool? withCredentials,
  String? responseType,
  String? mimeType,
  Map<String, String>? requestHeaders,
  sendData,
  void onProgress(ProgressEvent e)?,
}) {
  var completer = new Completer<HttpRequest>();

  var xhr = new HttpRequest();
  if (method == null) {
    method = 'GET';
  }
  xhr.open(method, url, async: true);

  if (withCredentials != null) {
    xhr.withCredentials = withCredentials;
  }

  if (responseType != null) {
    xhr.responseType = responseType;
  }

  if (mimeType != null) {
    xhr.overrideMimeType(mimeType);
  }

  if (requestHeaders != null) {
    requestHeaders.forEach((header, value) {
      xhr.setRequestHeader(header, value);
    });
  }

  if (onProgress != null) {
    xhr.onProgress.listen(onProgress);
  }

  xhr.onLoad.listen((e) {
    var status = xhr.status!;
    var accepted = status >= 200 && status < 300;
    var fileUri = status == 0; &#47;&#47; file:&#47;&#47; URIs have status of 0.
    var notModified = status == 304;
    &#47;&#47; Redirect status is specified up to 307, but others have been used in
    &#47;&#47; practice. Notably Google Drive uses 308 Resume Incomplete for
    &#47;&#47; resumable uploads, and it's also been used as a redirect. The
    &#47;&#47; redirect case will be handled by the browser before it gets to us,
    &#47;&#47; so if we see it we should pass it through to the user.
    var unknownRedirect = status > 307 && status < 400;

    if (accepted || fileUri || notModified || unknownRedirect) {
      completer.complete(xhr);
    } else {
      completer.completeError(e);
    }
  });

  xhr.onError.listen(completer.completeError);

  if (sendData != null) {
    xhr.send(sendData);
  } else {
    xhr.send();
  }

  return completer.future;
}

requestCrossOrigin() ​

Future<String> requestCrossOrigin(
  String url, {
  String? method,
  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
dart
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),
  );

  &#47;&#47; IE9 RTM - XDomainRequest issued requests may abort if all event handlers
  &#47;&#47; not specified
  &#47;&#47; http:&#47;&#47;social.msdn.microsoft.com&#47;Forums&#47;ie&#47;en-US&#47;30ef3add-767c-4436-b8a9-f1ca19b4812e&#47;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;
}

Constants ​

DONE ​

const int DONE
Implementation
dart
static const int DONE = 4;

HEADERS_RECEIVED ​

const int HEADERS_RECEIVED
Implementation
dart
static const int HEADERS_RECEIVED = 2;

LOADING ​

const int LOADING
Implementation
dart
static const int LOADING = 3;

OPENED ​

const int OPENED
Implementation
dart
static const int OPENED = 1;

readyStateChangeEvent ​

const EventStreamProvider<Event> readyStateChangeEvent

Static factory designed to expose readystatechange events to event handlers that are not necessarily instances of HttpRequest.

See EventStreamProvider for usage information.

Implementation
dart
static const EventStreamProvider<Event> readyStateChangeEvent =
    const EventStreamProvider<Event>('readystatechange');

UNSENT ​

const int UNSENT
Implementation
dart
static const int UNSENT = 0;