ReferenceError: GM_xmlhttpRequest is not defined

Question

I get a ReferenceError in the following userscript code:

// ==UserScript==
// @name          ...
// @namespace     ...
// @description   ...
// @include       ...
// @grant         GM_xmlhttpRequest
// ==/UserScript==

console.log(GM_info);
try
{
    console.log(GM_xmlhttpRequest({ method: "GET", url: "http://google.ca/", synchronous: true }).readyState);
}
catch (e)
{
    console.log(e);
}
...

It first logs GM_info successfully, then logs the ReferenceError. (I'm using Firefox/Firebug.)

ReferenceError: GM_xmlhttpRequest is not defined

Why do I get this error?

Solution 1

Reinstalling the script fixed the problem. I didn't need to restart Firefox, but it may be helpful for other people. Brock's answer has helpful debugging tips for problems like this.

Solution 2

Since the news version (GM 4.0) this error happened when you use GM_xmlhttpRequest because GM_xmlhttpRequest was replaced by : GM.xmlHttpRequest.

The new code is :

// ==UserScript==
// @name          ...
// @namespace     ...
// @description   ...
// @include       ...
// @grant         GM.xmlHttpRequest
// ==/UserScript==

console.log(GM_info);
try
{
    console.log(GM.xmlHttpRequest({ method: "GET", url: "http://google.ca/", synchronous: true }).readyState);
}
catch (e)
{
    console.log(e);
}
//...

Greasemonkey: "GM_xmlhttpRequest is not defined" with the new update

Comments

[neverMind9]

Should have kept backwards compatibility. Absolutely moronic changes.

[papo]

GM object's methods are async (as opposed to functions containing "_"). They will not slow down the page. Sometimes there is no progress without breaking something else. Do your new scripts the new way, for old scripts GM offered fast-fix. Just add: // @require https://greasemonkey.github.io/gm4-polyfill/gm4-polyfill.js reference