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XMLHttpRequestEventTarget.onloadstart

The XMLHttpRequestEventTarget.onloadstart is the function called when an XMLHttpRequest transaction starts transferring data.

Syntax

XMLHttpRequest.onloadstart = callback;

Values

  • callback is the function to be called when the transaction begins to transfer data.

Example

var xmlhttp = new XMLHttpRequest(),
  method = 'GET',
  url = 'https://developer.mozilla.org/';

xmlhttp.open(method, url, true);
xmlhttp.onloadstart = function () {
  console.log("Download underway");
};
xmlhttp.send();

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
onloadstart
1
12
3.5
10
≤12.1
4
1
18
4
≤12.1
3
1.0

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https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequestEventTarget/onloadstart