1 Minute Greasemonkey Guide#

Thu, 17 Jul 2008 15:13:31 +0000

I am a late but fervent convert to Greasemonkey, based on an hour playing with it last night.

1. install firebug and learn how to use it. This takes longer than a minute, but we assume you've done it already
2. write a javascript file with some funny comments at the top, and call it something.user.js
3. In Firefox 3, browse to the file and a popup will, er, pop up allowing you to install the script. In FF2, according to instructions I read there is an extra step here (you need to go to Tools -> Greasemonkey and do something that will probably be fairly obvious)
4. Installation will copy the script into your firefox profile directory somewhere (look in the gm_scripts subdir). You can edit the file in place thereafter instead of continually reinstalling
5. to print stuff to the firebug console, use unsafeWindow.console.log(stuff) - but be careful, the "unsafe" in the name is not just for show

A few words about the content of the script seem appropriate: it is executed when web pages are loaded (the special comments contain include and exclude directives for you to specify exactly which pages) and references to document do roughly what you'd expect - so, you can rewrite bits of the DOM tree of other people's websites in nasty brutal "if it breaks you can keep both pieces" hacky ways

Habitable Firefox. Yay

// This is a Greasemonkey user script.
//
// To install, you need Greasemonkey: http://greasemonkey.mozdev.org/
// Then restart Firefox and revisit this script.
//
// ==UserScript==
// name          phpbb killfile
// namespace     http://www.telent.net/
// description   brutal script to hide phpbb posts
// include       http://www.example.com/forum/*
// ==/UserScript==
var posts=document.evaluate("//span[@class='name']",document,null,
			    XPathResult.UNORDEREDNODESNAPSHOT_TYPE,null);
    
for(var i=0;i<posts.snapshotLength;i++) {
    var p=posts.snapshotItem(i);
    var name=p.firstChild.nextSibling.firstChild.nodeValue;
    var tr=p.parentNode.parentNode;
    if(name=='Moron') {
        while(tr.firstChild) tr.removeChild(tr.firstChild);
	var span=document.createElement("span");
	span.className="postbody";
        var replace=document.createElement("td");
	replace.setAttribute("COLSPAN","2");
	replace.setAttribute("ALIGN","CENTER");
	span.appendChild(document.createTextNode("post hidden"));
	replace.appendChild(span);
	tr.appendChild(replace);
    }
}

Probably I should confine the Include directive to viewtopic.php. Yes, I know a robust solution would include some kind of configuration options to change the list of ignored users, cope with multiple forums etc etc, but that's not the point. Quick and dirty.