cssrefresh.js

/*  
 *  CSSrefresh v1.0.3
 *  
 *  Copyright (c) 2012 Fred Heusschen
 *  www.frebsite.nl
 *
 *  Dual licensed under the MIT and GPL licenses.
 *  http://en.wikipedia.org/wiki/MIT_License
 *  http://en.wikipedia.org/wiki/GNU_General_Public_License
 */
(function() {

    var blockDomains = ["google.com","fonts.com"];

    function createCookie(name, value, days) {
        if (days) {
            var date = new Date();
            date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
            var expires = "; expires=" + date.toGMTString();
        } else var expires = "";
        document.cookie = name + "=" + value + expires + "; path=/";
    }

    function readCookie(name) {
        var nameEQ = name + "=";
        var ca = document.cookie.split(';');
        for (var i = 0; i < ca.length; i++) {
            var c = ca[i];
            while (c.charAt(0) == ' ') c = c.substring(1, c.length);
            if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
        }
        return null;
    }

    function eraseCookie(name) {
        createCookie(name, "", -1);
    }


    var phpjs = {

        array_filter: function(arr, func) {
            var retObj = {};
            for (var k in arr) {
                if (func(arr[k])) {
                    retObj[k] = arr[k];
                }
            }
            return retObj;
        },
        filemtime: function(file) {
            var headers = this.get_headers(file, 1);
            return (headers && headers['Last-Modified'] && Date.parse(headers['Last-Modified']) / 1000) || false;
        },
        get_headers: function(url, format) {
            var req = window.ActiveXObject ? new ActiveXObject('Microsoft.XMLHTTP') : new XMLHttpRequest();
            if (!req) {
                throw new Error('XMLHttpRequest not supported.');
            }

            var tmp, headers, pair, i, j = 0;

            try {
                req.open('HEAD', url, false);
                req.send(null);
                if (req.readyState < 3) {
                    return false;
                }
                tmp = req.getAllResponseHeaders();
                tmp = tmp.split('\n');
                tmp = this.array_filter(tmp, function(value) {
                    return value.toString().substring(1) !== '';
                });
                headers = format ? {} : [];

                for (i in tmp) {
                    if (format) {
                        pair = tmp[i].toString().split(':');
                        headers[pair.splice(0, 1)] = pair.join(':').substring(1);
                    } else {
                        headers[j++] = tmp[i];
                    }
                }

                return headers;
            } catch (err) {
                return false;
            }
        }
    };

    var cssRefresh = function(links) {

        this.reloadFile = function(links) {
            for (var a = 0, l = links.length; a < l; a++) {
                var link = links[a],
                    newTime = phpjs.filemtime(this.getRandom(link.href));

                //  has been checked before
                if (link.last) {
                    //  has been changed
                    if (link.last != newTime) {
                        //  reload

                        link.elem.setAttribute('href', this.getRandom(link.href));
                    }
                }

                //  set last time checked
                link.last = newTime;
            }
            setTimeout(function() {
                this.reloadFile(links);
            }, 1000);
        };

        this.getRandom = function(f) {
            return f + '?x=' + Math.random();
        };


        this.reloadFile(links);
    };

    var getLinks = function() {
        var files = document.getElementsByTagName('link'),
            links = [];

        for (var a = 0, l = files.length; a < l; a++) {
            var elem = files[a],
                rel = elem.rel,
                href = elem.getAttribute('href').split('?')[0],
                blockReg = "(" + blockDomains.join("|") + ")";

            if (href.match(new RegExp(/^https*:\/\/([^\.]+\.)*google.com.*/)));

            if (typeof rel != 'string' || rel.length == 0 || rel == 'stylesheet') {
                links.push({
                    'elem': elem,
                    'href': href,
                    'last': false
                });
            }
        }
        return links;
    };

    var links = getLinks(),
    cssRefresh(links);

})();