How to get Firefox Greasemonkey script to use a local cascading stylesheet?

Question

What's the correct syntax to link to a CSS file in the same directory as a Greasemonkey JavaScript? I've tried the following but it doesn't work:

var cssNode = document.createElement('link');
cssNode.type = 'text/css';
cssNode.rel = 'stylesheet';
cssNode.href = 'example.css';
cssNode.media = 'screen';
cssNode.title = 'dynamicLoadedSheet';
document.getElementsByTagName("head")[0].appendChild(cssNode);

If I can get this to work, it would be a lot easier than encasing CSS changes in JavaScript.

Brock Adams · Answer 1 · 2015-01-06T13:32:28.270

This is easy with the @resource directive. Like so:

// ==UserScript==
// @name            _Use external CSS file
// @resource        YOUR_CSS  YOUR_CSS_File.css
// @grant           GM_addStyle
// @grant           GM_getResourceText
// ==/UserScript==

var cssTxt  = GM_getResourceText ("YOUR_CSS");

GM_addStyle (cssTxt);

With no path/url information, @resource looks for "YOUR_CSS_File.css" in the same directory.

score 1 · Answer 2 · answered Nov 16 '12 at 11:09

I'm still unable to get a local CSS file working. However, I came across this tip (which works) and is a lot closer to what I was after:

GM_addStyle((<><![CDATA[

body { color: white; background-color: black }
img { border: 0 }
.footer {width:875px;}

]]></>).toString());

Thanks to Erik Vold.

score 1 · Answer 3 · edited May 31 '16 at 17:42

Try this!

function addStyleSheet(style){
  var getHead = document.getElementsByTagName("HEAD")[0];
  var cssNode = window.document.createElement( 'style' );
  var elementStyle= getHead.appendChild(cssNode)
  elementStyle.innerHTML = style;
  return elementStyle;
}


addStyleSheet('@import "example.css";');

Note: example.css must live in the same directory as your user script for this example to work.

Reference - > DiveIntoGreaseMonkey

score 0 · Answer 4 · edited Jan 06 '15 at 13:24

You need to pass the style sheet to the addStyleSheet function or it will not work.

function addStyleSheet(style){
  var getHead = document.getElementsByTagName("HEAD")[0];
  var cssNode = window.document.createElement( 'style' );
  var elementStyle= getHead.appendChild(cssNode);
  elementStyle.innerHTML = style;
  return elementStyle;
}

addStyleSheet('@import "http://wherever.com/style.css";');

To use a local file, change the last line to:

addStyleSheet('@import "style.css";');

This would load style.css in the same directory as the script.

How to get Firefox Greasemonkey script to use a local cascading stylesheet?

4 Answers4