Greasemonkey (and most userscript engines) has no built-in way to target a page by its elements. Your script needs to poll or use mechanisms like Mutation Observers to check for the desired elements.
A handy way to do this is to use the waitForKeyElements() utility, and you still want to use the @include
, @exclude
, and/or @match
directives to narrow down the page firings as much as possible.
Here is a complete Greasemonkey/Tampermonkey script illustrating the process:
// ==UserScript==
// @name _Do something after select posts
// @include http://www.example.com/cgi-bin/foo.pl*
// @require http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js
// @require https://gist.github.com/raw/2625891/waitForKeyElements.js
// @grant GM_addStyle
// ==/UserScript==
/*- The @grant directive is needed to work around a design change
introduced in GM 1.0. It restores the sandbox.
*/
function processTargetElement (jNode) {
//***** YOUR CODE HERE *****
jNode.css ("background", "pink");
}
waitForKeyElements ("#someIdentifier", processTargetElement);