Contains utility functions commonly-used in my Greasemonkey scripts

common_greasemonkey_utils.js

/*
 * Commonly used utility functions for Greasemonkey scripts
 *
 * Copyright © 2010, Yuri Sakhno
 */
// version 1.1
if (!Array.prototype.indexOf) {
    Array.prototype.indexOf = function(elt, from) {
        var len = this.length >>> 0;

        from = Number(from) || 0;
        from = (from < 0) ? Math.ceil(from) : Math.floor(from);

        if (from < 0) {
            from = Math.max(0, from + len);
        }

        for (; from < len; ++from) {
            if (from in this && this[from] === elt) return from;
        }

        return -1;
    };
}
if (!Array.prototype.lastIndexOf) {
    Array.prototype.lastIndexOf = function(elt, from) {
        var len = this.length;

        from = Number(from) || len-1;
        from = (from < 0) ? Math.ceil(from) : Math.floor(from);

        if (from < 0) {
            from += len;
        } else if (from >= len) {
            from = len - 1;
        }

        for (; from > -1; --from) {
            if (from in this && this[from] === elt) return from;
        }

        return -1;
    };
}
Date.prototype.daysInMonth=function(){var n=31;switch(this.getMonth()){case 1:n=this.isLeapYear()?29:28;break;case 3:
case 5:case 8:case 10:--n}return n};Array.prototype.chop=function(s){var i=0,c=-1,a=[];for(;i<this.length;++i)i%s?a[c].
push(this[i]):a[++c]=[this[i]];return a};Date.prototype.isLeapYear=function(){var y=this.getFullYear();return!(y%400)||(
y%100!=0&&y%4==0)};Number.prototype.clamp=function(l,u){return Math.max(l,Math.min(this,u))};Number.prototype.
toHexString=function(w){if(w==undefined)w=1;var s=this.toString(16).upper();while(s.length<w)s="0"+s;return s};String.
prototype._split=String.prototype.split;String.prototype.contains=function(s){return-1<this.indexOf(s)};String.prototype
.endsWith=function(s){var i=this.lastIndexOf(s);return i+1&&i==this.length-s.length};String.prototype.startsWith=
function(s){return!this.indexOf(s)};String.prototype.replaceFast=function(t,r,f){return this.split(t,f?f+1:null).join(r)
};String.prototype.lower=function(){return this.toLowerCase()};String.prototype.upper=function(){return this.toUpperCase
()};String.prototype.lowerL=function(){return this.toLocaleLowerCase()};String.prototype.upperL=function(){return this.
toLocaleUpperCase()};String.prototype.reverse=function(){return this._split("").reverse().join("")};String.prototype.
split=function(d,l){var s=this._split(d);if(l&&s.length>l)s.push(s.splice(l-1).join(d));return s};String.prototype.trim=
function(){var s=0,e=this.length-1;for(;e+1;--e)if(this[e]>' ')break;for(;s<=e;++s)if(this[s]>' ')break;return s>e?"":s
||e+1!=this.length?this.substr(s,e+1-s):this}
function byId(i){return document.getElementById(i)}function removeChildNode(n){if(n)n.parentNode.removeChild(n)}function
removeAllChildren(e){for(var c=e.childNodes,i=c.length;i;--i)e.removeChild(c[i-1])}function selectSingleNode(p,c,d){d=d
||document;var n=d.evaluate(p,c||d,null,XPathResult.ANY_TYPE,null).iterateNext();return n}function insertNodeAfter(n,r){
var s=r.nextSibling,p=r.parentNode;if(s)p.insertBefore(n,s);else p.appendChild(n);return n}function setCookie(n,v,e,p,d,
s){var t=new Date;t.setTime(t.getTime()+(e?e*72e5:0));document.cookie=n+"="+escape(v)+(e?";expires="+t.toGMTString():"")
+(p?";path="+p:"")+(d?";domain="+d:"")+(s?";s":"")}function selectNodes(p,c){return document.evaluate(p,c||document,null
,XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,null)}function getParamFromStr(s,n,i,j){var b=0,c='a',e;n+="=";while(c>' '&&c
!=i&&c!=j){b=s.indexOf(n,b);if(b<0)return null;c=b?s[b-1]:j;b+=n.length}e=s.indexOf(i,b);return unescape(s.slice(b,e<0?s
.length:e))}function deleteCookie(n,p,d){if(getCookie(n))document.cookie=n+"="+";expires=Thu, 01 Jan 1970 00:00:01 GMT"+
(p?";path="+p:"")+(d?";domain="+d:"")}function getCookie(n){return getParamFromStr(document.cookie,n,';',' ')}function
getNextElementByTagName(c,t,i){if(!c)return null;if(i==null)i=true;if(t)t=t.lower();for(c=c.nextSibling;c&&(c.nodeType!=
1||c.tagName.lower()!=t);c=c.nextSibling)if((!t||i)&&c.nodeType==1)return!t?c:null;return c}function getElementByTagName
(p,t,x){if(!p)return null;if(!x)x=0;t=t.lower();for(var i=0,c=p.childNodes;i<c.length;++i){p=c[i];if(p.nodeType==1&&p.
tagName.lower()==t&&!x--)return p}return null}function getPreviousElementByTagName(c,t,i){if(!c)return null;if(i==null)i
=true;if(t)t=t.lower();for(c=c.previousSibling;c&&(c.nodeType!=1||c.tagName.lower()!=t);c=c.previousSibling)if((!t||i)&&
c.nodeType==1)return!t?c:null;return c}function getAllElementsByTagName(p,t){if(!p)return[];t=t.lower();var e=[],c=p.
childNodes,i;for(i=0;i<c.length;++i){p=c[i];if(p.nodeType==1&&p.tagName.lower()==t)e.push(p)}return e}function
addGlobalStyle(c){var n=selectNodes("//style|//link[@type='text/css'][@rel='stylesheet']"),s=document.createElement(
"style");if(n.snapshotLength>0)insertNodeAfter(s,n.snapshotItem(n.snapshotLength-1));else document.body.appendChild(s);s
.type="text/css";s.textContent=c}function getParameterValueFromURL(u,n){return getParamFromStr(u,n,'&','?')}

function UrlParameter(/*String*/ name, /*String*/ value) {

    this.setValue = function(/*String*/ value) {
        this.value = value ? unescape(value) : "";
    };

    this.toString = function() {
        return this.name + "=" + escape(this.value);
    };

    this.name = name;
    this.setValue(value);
}

function UrlParameters() {

    this.add = function(/*String*/ name, /*String*/ value) {
        var i = this.p.length;

        this.p[i] = new UrlParameter(name, value);
        if (this.contains(name)) {
            ++this.c[name];
        } else {
            this.c[name] = 1;
            this.i[name] = i;
        }
    };

    this.addQuery = function(/*String*/ query) {
        this.clear();

        var params = query.split("&");

        for (var i = 0; i < params.length; ++i) {
            var pair = params[i].split("=", 2);

            if (pair.length == 2) this.add(pair[0], pair[1]);
        }
    };

    this.clear = function() {
        this.p = [];
        this.i = [];
        this.c = [];
    };

    this.contains = function(/*String*/ name) {
        return this.c[name];
    };

    this.get = function(/*String*/ name) {
        return this.c[name]?this.p[this.i[name]].value:null;
    };

    this.getAll = function(/*String*/ name) {
        if (!this.c[name]) return [];
        if (this.c[name] == 1) return[this.get(name)];

        var arr = [], i;

        for (i = 0; i < this.p.length; ++i) {
            if (this.p[i].name == name) arr.push(this.p[i].value);
        }

        return arr;
    };

    this.isEmpty = function() {
        return !this.p.length;
    };

    this.remove = function(/*String*/ name) {
        if (this.c[name]) {
            this.p.splice(this.i[name], 1);

            if (--this.c[name]) {
                for (var i = this.i[name]; i < this.p.length && this.p[i].name != name; this.i[name] = ++i);
            }
        }
    }

    this.removeAll = function(/*String*/ name) {
        if (this.c[name]) {
            for (var i = this.p.length-1; i+1; --i) {
                if (this.p[i].name == name) this.p.splice(i, 1);
            }

            this.c[name] = 0;
        }
    };

    this.set = function(/*String*/ name, /*String*/ value) {
        if (this.c[name]) {
            this.p[this.i[name]].setValue(value);
        } else {
            this.add(name, value);
        }
    };

    this.toString = function() {
        var s = "";

        for (var i = 0; i < this.p.length; ++i) {
            s += (i ? "&" : "?") + this.p[i];
        }

        return s;
    };

    this.clear();
}

function Url(/*String*/ url) {

    this.setUrl = function(/*String*/ url) {
        this.scheme = null;
        this.host = null;
        this.port = null;
        this.path = null;
        this.search = new UrlParameters();
        this.anchor = null;

        var start = 0,
            end = url.indexOf("#");

        if (end+1) {
            this.anchor = url.substr(end+1);
            url = slice(0, end);
        }

        end = url.indexOf("://");

        if (end+1) {
            this.scheme = (end > 0) ? url.slice(start, end) : null;
            start = end + 3;
        }

        if (this.scheme) {
            end = url.indexOf("/", start);

            if (start < end) {
                var end2 = url.indexOf(":", start);

                if (start < end2 && end2 < end) {
                    this.host = url.slice(start, end2++);
                    this.port = (end2 < end) ? url.slice(end2, end) : null;
                } else {
                    this.host = url.slice(start, end);
                }

                start = end;
            }
        }

        end = url.indexOf("?");

        if (start <= end) {
            this.path = (start<end) ? url.slice(start, end++) : null;
            this.search.addQuery(url.substr(end));
        } else {
            this.path = url.substr(start);
        }
    }

    this.toString = function() {
        return (this.scheme ? this.scheme + "://" : "") +
                (this.host ? this.host + (this.port ? ":" + this.port : "") : "") +
                (this.path || "") +
                this.search +
                (this.anchor ? "#" + this.anchor : "");
    }

    this.setUrl(url);
}