An event handler that is called whenever the readyState
attribute changes. The callback is called from the user interface thread. The XMLHttpRequest.onreadystatechange
property contains the event handler to be called when the readystatechange
event is fired, that is every time the readyState
property of the XMLHttpRequest
changes.
Warning: This should not be used with synchronous requests and must not be used from native code.
XMLHttpRequest.onreadystatechange = callback;
callback
is the function to be executed when the readyState
changes. const xhr = new XMLHttpRequest(), method = "GET", url = "https://developer.mozilla.org/"; xhr.open(method, url, true); xhr.onreadystatechange = function () { // In local files, status is 0 upon success in Mozilla Firefox if(xhr.readyState === XMLHttpRequest.DONE) { var status = xhr.status; if (status === 0 || (status >= 200 && status < 400)) { // The request has been completed successfully console.log(xhr.responseText); } else { // Oh no! There has been an error with the request! } } }; xhr.send();
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
onreadystatechange |
1 |
12 |
1 |
5 |
9 |
1.2 |
1 |
18 |
4 |
10.1 |
1 |
1.0 |
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https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/onreadystatechange