HTML Encode & Decode

encodedecode.js

var js = {}
js.lang = {}
js.lang.String = function () {

    this.REGX_HTML_ENCODE = /"|&|'|<|>|[\x00-\x20]|[\x7F-\xFF]|[\u0100-\u2700]/g;

    this.REGX_HTML_DECODE = /&\w+;|&#(\d+);/g;

    this.REGX_TRIM = /(^\s*)|(\s*$)/g;

    this.HTML_DECODE = {
        "&lt;": "<", 
        "&gt;": ">", 
        "&amp;": "&", 
        "&nbsp;": " ", 
        "&quot;": "\"", 
        "©": ""

        // Add more
    };

    this.encodeHtml = function (s) {
        s = (s != undefined) ? s : this.toString();
        return (typeof s != "string") ? s :
            s.replace(this.REGX_HTML_ENCODE, function ($0) {
                var c = $0.charCodeAt(0),
                    r = ["&#"];
                c = (c == 0x20) ? 0xA0 : c;
                r.push(c);
                r.push(";");
                return r.join("");
            });
    };

    this.decodeHtml = function (s) {
        var HTML_DECODE = this.HTML_DECODE;

        s = (s != undefined) ? s : this.toString();
        return (typeof s != "string") ? s :
            s.replace(this.REGX_HTML_DECODE, function ($0, $1) {
                var c = HTML_DECODE[$0];
                if(c == undefined){
                    // Maybe is Entity Number
                    if (!isNaN($1)) {
                            c = String.fromCharCode(($1 == 160) ? 32 : $1);
                    } else {
                            c = $0;
                    }
                }
                return c;
            });
    };

    this.trim = function (s) {
        s = (s != undefined) ? s : this.toString();
        return (typeof s != "string") ? s :
            s.replace(this.REGX_TRIM, "");
    };


    this.hashCode = function () {
        var hash = this.__hash__,
            _char;
        if (hash == undefined || hash == 0) {
            hash = 0;
            for (var i = 0, len = this.length; i < len; i++) {
                _char = this.charCodeAt(i);
                hash = 31*hash + _char;
                hash = hash & hash; // Convert to 32bit integer
            }
            hash = hash & 0x7fffffff;
        }
        this.__hash__ = hash;

        return this.__hash__;
    };
};

js.lang.String.call(js.lang.String);