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url encoding function that can't cope with euro signs

Posted: Thu Mar 23, 2006 5:55 am
by Skittlewidth
I've used this javascript function for encoding strings I want to pass via a query string with Ajax as escape() is not adequate. Problem is, (and this is why I try to avoid using other people's code), I haven't got a clue how it does what its doing.

I've just realised that this function can't cope with converting the euro symbol from unicode to hex, but I don't know why, and whether there is anyway to fix it. The function just throws up its standard alert "Unicode character '€' cannot be encoded using standard URL encoding.(URL encoding only supports 8-bit characters.) A space (+) will be substituted."

How can I adapt this code so that it can cope with more than 8-bit chars (and also why is € more than 8-bit?)

Code: Select all

function URLEncode(text )
{
	// The Javascript escape and unescape functions do not correspond
	// with what browsers actually do...
	var SAFECHARS = "0123456789" +					// Numeric
					"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +	// Alphabetic
					"abcdefghijklmnopqrstuvwxyz" +
					"-_.!~*'()";					// RFC2396 Mark characters
	var HEX = "0123456789ABCDEF";

	var plaintext = text;
	var encoded = "";
	for (var i = 0; i < plaintext.length; i++ ) {
		var ch = plaintext.charAt(i);
	    if (ch == " ") {
		    encoded += "+";				// x-www-urlencoded, rather than %20
		} else if (SAFECHARS.indexOf(ch) != -1) {
		    encoded += ch;
		} else {
		    var charCode = ch.charCodeAt(0);
			if (charCode > 255) {
			    alert( "Unicode Character '" 
                        + ch 
                        + "' cannot be encoded using standard URL encoding.\n" +
				          "(URL encoding only supports 8-bit characters.)\n" +
						  "A space (+) will be substituted." );
				encoded += "+";
			} else {
				encoded += "%";
				encoded += HEX.charAt((charCode >> 4) & 0xF);
				encoded += HEX.charAt(charCode & 0xF);
			}
		}
	} // for

	//document.URLForm.F2.value = encoded;
	return encoded;
};
8O

Posted: Thu Mar 23, 2006 6:08 am
by Benjamin
Add it to the var SAFECHARS array and go from there.

EDIT: That will only fix it if it doesn't need to be url encoded.

Posted: Thu Mar 23, 2006 6:38 am
by Skittlewidth
Yep, quite right.

It had half occured to me that that might be the solution, but being a special character I thought it might cause problems.

Anyway, thanks.