XMLHttpRequest

ใช้วัตถุ (XHR) เพื่อโต้ตอบกับเซิร์ฟเวอร์ คุณสามารถดึงข้อมูลจาก URL โดยไม่ต้องทำการฟื้นฟูเต็มหน้า เว็บเพจการปรับปรุงเพียงบางส่วนของหน้าโดยไม่กระทบกับสิ่งที่ผู้ใช้จะทำได้XMLHttpRequest XMLHttpRequest ใช้มากใน AJAX เขียนโปรแกรม

แม้จะชื่อ สามารถใช้ในการดึงข้อมูลทุกประเภทของข้อมูล XML ไม่เพียงXMLHttpRequest

ถ้าจำเป็นต้องเกี่ยวข้องกับการได้รับข้อมูลเหตุการณ์หรือข้อความจากเซิร์ฟเวอร์สื่อสารของคุณ ลองใช้กิจกรรมเซิร์ฟเวอร์ส่งผ่านอินเทอร์เฟซ EventSource (en-US) สำหรับเพล็กซ์การสื่อสารWebSocketsอาจเป็นทางเลือกที่ดี

Constructor

XMLHttpRequest() (en-US)
The constructor initializes an XMLHttpRequest. It must be called before any other method calls.

Properties

This interface also inherits properties of XMLHttpRequestEventTarget (en-US) and of EventTarget (en-US).

XMLHttpRequest.onreadystatechange (en-US)
An EventHandler (en-US) that is called whenever the attribute changes.readyState
XMLHttpRequest.readyState (en-US) Read only
Returns an , the state of the request.unsigned short
XMLHttpRequest.response (en-US) Read only
Returns an ArrayBuffer, Blob (en-US), Document (en-US), JavaScript object, or a DOMString (en-US), depending on the value of XMLHttpRequest.responseType (en-US), that contains the response entity body.
XMLHttpRequest.responseText (en-US) Read only
Returns a DOMString (en-US) that contains the response to the request as text, or if the request was unsuccessful or has not yet been sent.null
XMLHttpRequest.responseType (en-US)
Is an enumerated value that defines the response type.
XMLHttpRequest.responseURL (en-US) Read only
Returns the serialized URL of the response or the empty string if the URL is null.
XMLHttpRequest.responseXML (en-US) Read only
Returns a Document (en-US) containing the response to the request, or if the request was unsuccessful, has not yet been sent, or cannot be parsed as XML or HTML. Not available in workers.null
XMLHttpRequest.status (en-US) Read only
Returns an with the status of the response of the request.unsigned short
XMLHttpRequest.statusText (en-US) Read only
Returns a DOMString (en-US) containing the response string returned by the HTTP server. Unlike XMLHttpRequest.status (en-US), this includes the entire text of the response message ("", for example).200 OK

Note: According to the HTTP/2 specification (8.1.2.4 Response Pseudo-Header Fields), HTTP/2 does not define a way to carry the version or reason phrase that is included in an HTTP/1.1 status line.

XMLHttpRequest.timeout (en-US)
Is an representing the number of milliseconds a request can take before automatically being terminated.unsigned long
XMLHttpRequestEventTarget.ontimeout
Is an EventHandler (en-US) that is called whenever the request times out.
XMLHttpRequest.upload (en-US) Read only
Is an XMLHttpRequestUpload, representing the upload process.
XMLHttpRequest.withCredentials (en-US)
Is a Boolean (en-US) that indicates whether or not cross-site requests should be made using credentials such as cookies or authorization headers.Access-Control

Non-standard properties

XMLHttpRequest.channel (en-US)Read only
Is a nsIChannel. The channel used by the object when performing the request.
XMLHttpRequest.mozAnon (en-US)Read only
Is a boolean. If true, the request will be sent without cookie and authentication headers.
XMLHttpRequest.mozSystem (en-US)Read only
Is a boolean. If true, the same origin policy will not be enforced on the request.
XMLHttpRequest.mozBackgroundRequest (en-US)
Is a boolean. It indicates whether or not the object represents a background service request.
XMLHttpRequest.mozResponseArrayBuffer (en-US) Obsolete since Gecko 6 Read only
ArrayBuffer. The response to the request, as a JavaScript typed array.
XMLHttpRequest.multipart (en-US)Obsolete since Gecko 22
This Gecko-only feature, a boolean, was removed in Firefox/Gecko 22. Please use Server-Sent Events, Web Sockets, or from progress events instead.responseText

Event handlers

onreadystatechange as a property of the instance is supported in all browsers.XMLHttpRequest

Since then, a number of additional event handlers have been implemented in various browsers (, , , etc.). See Using XMLHttpRequest.onloadonerroronprogress

More recent browsers, including Firefox, also support listening to the events via standard addEventListener() (en-US) APIs in addition to setting properties to a handler function.XMLHttpRequeston*

Methods

XMLHttpRequest.abort() (en-US)
Aborts the request if it has already been sent.
XMLHttpRequest.getAllResponseHeaders() (en-US)
Returns all the response headers, separated by CRLF, as a string, or if no response has been received.null
XMLHttpRequest.getResponseHeader() (en-US)
Returns the string containing the text of the specified header, or if either the response has not yet been received or the header doesn't exist in the response.null
XMLHttpRequest.open() (en-US)
Initializes a request. This method is to be used from JavaScript code; to initialize a request from native code, use openRequest() instead.
XMLHttpRequest.overrideMimeType() (en-US)
Overrides the MIME type returned by the server.
XMLHttpRequest.send() (en-US)
Sends the request. If the request is asynchronous (which is the default), this method returns as soon as the request is sent.
XMLHttpRequest.setRequestHeader() (en-US)
Sets the value of an HTTP request header. You must call after open(), but before .setRequestHeader()send()

Non-standard methods

XMLHttpRequest.init()
Initializes the object for use from C++ code.
Warning: This method must not be called from JavaScript.
XMLHttpRequest.openRequest()
Initializes a request. This method is to be used from native code; to initialize a request from JavaScript code, use open() instead. See the documentation for .open()
XMLHttpRequest.sendAsBinary() This deprecated API should no longer be used, but will probably still work.
A variant of the method that sends binary data.send()

Events

abort (en-US)
Fired when a request has been aborted, for example because the program called XMLHttpRequest.abort() (en-US).
Also available via the onabort (en-US) property.
error (en-US)
Fired when the request encountered an error.
Also available via the onerror (en-US) property.
load (en-US)
Fired when an XMLHttpRequest transaction completes successfully.
Also available via the onload (en-US) property.
loadend (en-US)
Fired when a request has completed, whether successfully (after load (en-US)) or unsuccessfully (after abort (en-US) or error (en-US)).
Also available via the onloadend property.
loadstart (en-US)
Fired when a request has started to load data.
Also available via the onloadstart (en-US) property.
progress (en-US)
Fired periodically when a request receives more data.
Also available via the onprogress (en-US) property.
timeout (en-US)
Fired when progress is terminated due to preset time expiring.
Also available via the ontimeout property.

Specifications

Specification Status Comment
XMLHttpRequest Living Standard Live standard, latest version

Browser compatibility

BCD tables only load in the browser

See also