Simple JS object to encode text to its unicode character references for URLs and HTML. Makes displaying text and passing data to a server super safe.

Encoder.js

/////////////////
// HTML EXAMPLES
/////////////////
// Encoder.html_entities("常用國字標準字體表");    "常用國字標準字體表"
// Encoder.html_entities("%");                  "%"
// Encoder.html_entities("Pig: €3.99 (£6.77)"); "Pig: €3.99 (£6.77)"
/////////////////
// URL EXAMPLES
/////////////////
// Encoder.url_encode("常用國字標準字體表");      "%u5E38%u7528%u570B%u5B57%u6A19%u6E96%u5B57%u9AD4%u8868"
// Encoder.url_encode("%");                    "%u0025"
// Encoder.url_encode("Pig: €3.99 (£6.77)");   "Pig%u003A%u0020%u20AC3%u002E99%u0020%u0028%u00A36%u002E77%u0029"
/////////////////
// Encodes all characters that don't match [A-Za-z0-9_-] (change the regex below to allow other safe entities like .' etc)

var Encoder =
{
	url_encode: function(str)
	{
		return this._hexify_string(str, '%u', '');
	},
	html_entities: function(str)
	{
		return this._hexify_string(str, '&#x', ';');
	},
	_zero_pad: function(input, zeros)
	{
		input = input.toString();
		if(input.length < zeros)
		{
			return new Array((zeros - input.length) + 1).join(0) + input;
		} else return input;
	},
	_hexify_string: function(str, prepend, append)
	{
		var string = str.toString().split("");
		var result = '';
		for(var i = 0;i < string.length;i++)
		{
			if(string[i].match(/[A-Za-z0-9_-]/)) result += string[i];
			else
			{
				result += prepend;
				result += this._zero_pad(string[i].charCodeAt(0).toString(16), 4).toUpperCase();
				result += append;
			}
		}
		return result;
	},
};