Tampermonkey script: Different Trello background every day Raw

script.js

// ==UserScript==
// @name         Trello
// @namespace    http://namekdev.net
// @version      0.2
// @description  different Trello background every day
// @author       Namek
// @include      /^https?://trello\.com/?.*$/
// @grant        none
// ==/UserScript==

function createStyle(css) {
    var style = document.createElement('style');
    style.type = 'text/css';
    style.innerHTML = css;
    return style;
}

// got it from here: https://gist.github.com/BrockA/2625891
function waitForKeyElements (
    selectorTxt,    /* Required: The jQuery selector string that
                        specifies the desired element(s).
                    */
    actionFunction, /* Required: The code to run when elements are
                        found. It is passed a jNode to the matched
                        element.
                    */
    bWaitOnce,      /* Optional: If false, will continue to scan for
                        new elements even after the first match is
                        found.
                    */
    iframeSelector  /* Optional: If set, identifies the iframe to
                        search.
                    */
) {
    var targetNodes, btargetsFound;

    if (typeof iframeSelector == "undefined")
        targetNodes     = $(selectorTxt);
    else
        targetNodes     = $(iframeSelector).contents ()
                                           .find (selectorTxt);

    if (targetNodes  &&  targetNodes.length > 0) {
        btargetsFound   = true;
        /*--- Found target node(s).  Go through each and act if they
            are new.
        */
        targetNodes.each ( function () {
            var jThis        = $(this);
            var alreadyFound = jThis.data ('alreadyFound')  ||  false;

            if (!alreadyFound) {
                //--- Call the payload function.
                var cancelFound     = actionFunction (jThis);
                if (cancelFound)
                    btargetsFound   = false;
                else
                    jThis.data ('alreadyFound', true);
            }
        } );
    }
    else {
        btargetsFound   = false;
    }

    //--- Get the timer-control variable for this selector.
    var controlObj      = waitForKeyElements.controlObj  ||  {};
    var controlKey      = selectorTxt.replace (/[^\w]/g, "_");
    var timeControl     = controlObj [controlKey];

    //--- Now set or clear the timer as appropriate.
    if (btargetsFound  &&  bWaitOnce  &&  timeControl) {
        //--- The only condition where we need to clear the timer.
        clearInterval (timeControl);
        delete controlObj [controlKey]
    }
    else {
        //--- Set a timer, if needed.
        if ( ! timeControl) {
            timeControl = setInterval ( function () {
                    waitForKeyElements (    selectorTxt,
                                            actionFunction,
                                            bWaitOnce,
                                            iframeSelector
                                        );
                },
                300
            );
            controlObj [controlKey] = timeControl;
        }
    }
    waitForKeyElements.controlObj   = controlObj;
}



var colors = ["673ab7","3f51b5","2196f3","03a9f4","0288d1","01579b","006064","26c6da","0091ea","4caf50","2e7d32","00695c","64ffda","00c853","8bc34a","ffc107","ffb300","ff9800","f4511e","bf360c","795548","9e9e9e","fafafa","9e9e9e","757575","6d4c41","607d8b","b0bec5","78909c","455a64","212121"];

var oneDayInMs = 1000*60*60*24;
var currentTimeInMs = new Date().getTime(); // UTC time
var timeInDays = Math.floor(currentTimeInMs / oneDayInMs);
var numberForToday = timeInDays % 9999;
var index = numberForToday % colors.length;
var color = '#' + colors[index];


var style = createStyle('body{background-color:' + color + ' !important;}');
var alreadyAdded = false;

// add style on board page
waitForKeyElements(".board-wrapper", function() {
    if (!alreadyAdded) {
        document.body.appendChild(style);
        alreadyAdded = true;
    }
});

// remove style on board list page
waitForKeyElements('.member-boards-view', function() {
    if (style.parentNode) {
        style.parentNode.removeChild(style);
    }
    alreadyAdded = false;
});