abort

Summary

Stops an asynchronous XMLHttpRequest in progress.

Method of apis/xhr/XMLHttpRequestapis/xhr/XMLHttpRequest

Syntax

 .abort();

Return Value

No return value

Examples

function request() {
    var xhr = new XMLHttpRequest();
    xhr.open("GET", "http://localhost/test.xml", true);
    xhr.send();
    return xhr;
}

document.getElementById('submit').addEventListener('click', function () {
    var xhr = request(),
        submit = this,
        cancel = document.getElementById('cancel');

    function detach() {
        submit.removeEventListener('click', canceling, false);
        cancel.removeEventListener('click', canceling, false);
    }

    function canceling() {
        detach();
        xhr.abort();
    }

    // detach any remaining handlers after XHR finishes
    xhr.addEventListener('load', detach, false);

    // cancel if "Submit" is clicked again before XHR finishes
    submit.addEventListener('click', canceling, false);

    // cancel if "Cancel" is clicked
    cancel.addEventListener('click', canceling, false);
}, false);

Notes

Calling abort resets the object; the readyState is changed to 0 (uninitialized). Calling it on an already aborted request throws an exception.

Related specifications

W3C XMLHttpRequest Specification

W3C Working Draft

Attributions

• Microsoft Developer Network: Windows Internet Explorer API reference Article