Remove part of title of website via userscript

Question

I try to code a userscript that removes everything from the title of a website (flash browsergame) but the countdown that appears when starting an action.

I'm new to Javascript and need some help.

UPDATE

The regexp problem is solved but I still need some help getting this script to "monitor" the title so everytime it's changes by the game the script runs again.

The main title looks like this:

Shakes & Fidget - The Game (buffed buffed)

As soon as an action is started a countdown is added to the beginning so the title changes to

02:26 - Shakes & Fidget - The Game (buffed buffed)

I want the title to show the countdown only.

I searched the net and found different ways to do this but none of them works for me.

Here is what I currently have:

// ==UserScript==
// @name       Shakes & Fidget Buffed title shortener
// @namespace  http://släcker.de
// @version    0.1
// @description  Removes the page title of Shakes & Fidget to only display left time if it exists
// @include        *.sfgame.*
// @exclude        www.sfgame.*
// @exclude        sfgame.*
// @copyright  2013+, slaecker
// ==/UserScript==

var regex = [^0-9:]

function cleanTitle() { 
    var oldTitle = document.title; 
    var oldTitleRX = oldTitle.match(regex);
    document.title = oldTitle.replace(oldTitleRX,""); 
    return oldTitle; 
} 


cleanTitle()

The Javascript console shows errors concerning the regex. I tried to escape the characters but the errors are the same:

env: ERROR: Syntax error @ 'Shakes & Fidget Buffed title shortener'!
Unexpected token ^
SyntaxError: Unexpected token ^
    at Window.Function (<anonymous>)
    at L (eval at <anonymous> (eval at <anonymous> (chrome-extension://dhdgffkkebhmkfjojejmpbldmpobfkfo/content.js:51:21)), <anonymous>:156:21)
    at n (eval at <anonymous> (eval at <anonymous> (chrome-extension://dhdgffkkebhmkfjojejmpbldmpobfkfo/content.js:51:21)), <anonymous>:384:2)
    at R (eval at <anonymous> (eval at <anonymous> (chrome-extension://dhdgffkkebhmkfjojejmpbldmpobfkfo/content.js:51:21)), <anonymous>:388:86)
    at Q (eval at <anonymous> (eval at <anonymous> (chrome-extension://dhdgffkkebhmkfjojejmpbldmpobfkfo/content.js:51:21)), <anonymous>:194:40)
Uncaught SyntaxError: Unexpected token ^
L
n
R
Q

It has to be a regex match because the containing string "(buffed buffed)" changes (it shows the server name).

Another problem is that the script should "monitor" the title because it changes everytime a new action is started or finished but my script only runs once (tested it without regex).

Thanks in advance for your help,

slaecker

Answer 1

For the regex, use:

document.title = document.title.replace (/[^0-9:]/g, "");

To detect title changes, use MutationObservers, a new HTML5 feature that is implemented in both Google Chrome and Firefox (The two main userscripts browsers).

This complete script will work:

// ==UserScript==
// @name        Shakes & Fidget Buffed title shortener
// @namespace   http://släcker.de
// @version     0.1
// @description  Removes the page title of Shakes & Fidget to only display left time if it exists
// @include     *.sfgame.*
// @exclude     www.sfgame.*
// @exclude     sfgame.*
// @copyright   2013+, slaecker, Stack Overflow
// @grant       GM_addStyle
// ==/UserScript==
/*- The @grant directive is needed to work around a design change
    introduced in GM 1.0.   It restores the sandbox.
*/

var MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
var myObserver       = new MutationObserver (titleChangeDetector);
var obsConfig        = {
    //-- Subtree needed.
    childList: true, characterData: true, subtree: true
};

myObserver.observe (document, obsConfig);

function titleChangeHandler () {
    this.weInitiatedChange      = this.weInitiatedChange || false;
    if (this.weInitiatedChange) {
        this.weInitiatedChange  = false;
        //-- No further action needed
    }
    else {
        this.weInitiatedChange  = true;
        document.title = document.title.replace (/[^0-9:]/g, "");
    }
}

function titleChangeDetector (mutationRecords) {

    mutationRecords.forEach ( function (mutation) {
        //-- Sensible, Firefox
        if (    mutation.type                       == "childList"
            &&  mutation.target.nodeName            == "TITLE"
        ) {
            titleChangeHandler ();
        }
        //-- WTF, Chrome
        else if (mutation.type                      == "characterData"
            &&  mutation.target.parentNode.nodeName == "TITLE"
        ) {
            titleChangeHandler ();
        }
    } );
}

//-- Probably best to wait for first title change, but uncomment the next line if desired.
//titleChangeHandler ();

---

If you are using some other browser (state that in the question), then fallback to using setInterval().