utftools.js

// url encoding
utfTools.prototype.encode = function (string) {
	return escape(this._utf8_encode(string));
}
 
// url decoding
utfTools.prototype.decode = function (string) {
	return this._utf8_decode(unescape(string));
}
 
// private method UTF-8 encoding
utfTools.prototype._utf8_encode = function (string) {
	string = string.replace(/\r\n/g,"\n");
	var utftext = "";

	for (var n = 0; n < string.length; n++) {

		var c = string.charCodeAt(n);

		if (c < 128) {
			utftext += String.fromCharCode(c);
		}
		else if((c > 127) && (c < 2048)) {
			utftext += String.fromCharCode((c >> 6) | 192);
			utftext += String.fromCharCode((c & 63) | 128);
		}
		else {
			utftext += String.fromCharCode((c >> 12) | 224);
			utftext += String.fromCharCode(((c >> 6) & 63) | 128);
			utftext += String.fromCharCode((c & 63) | 128);
		}

	}

	return utftext;
}
 
// private method UTF-8 decoding
utfTools.prototype._utf8_decode = function (utftext) {
	var string = "";
	var i = 0;
	var c = c1 = c2 = 0;

	while ( i < utftext.length ) {

		c = utftext.charCodeAt(i);

		if (c < 128) {
			string += String.fromCharCode(c);
			i++;
		}
		else if((c > 191) && (c < 224)) {
			c2 = utftext.charCodeAt(i+1);
			string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
			i += 2;
		}
		else {
			c2 = utftext.charCodeAt(i+1);
			c3 = utftext.charCodeAt(i+2);
			string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
			i += 3;
		}

	}

	return string;
}