Actionscript problems with social share encoding

Question

Hi,

I'm trying to make some "social share" buttons at my site, but the urls I generate just don't get decoded by this services.

One example, for twitter:

private function twitter(e:Event):void {
  var message:String = "Message with special chars âõáà";
  var url:String = "http://www.twitter.com/home?status=";
  var link:URLRequest = new URLRequest( url + escape(message) );
}

But when twitter opens up, the message is:

Message with special chars %E2%F5%E1%E0

Something similar is happening with Facebook and Orkut (but these two hide the special chars).

Someone know why is this happening?

Answer 1

The problem is that the escape() function doesn't take UTF-8 enconding into account. The function you want for encoding the querystring using UTF-8 is encodeURIComponent().

So, let's say you have an "ñ" (eñe in Spanish, or n plus tilde). I'm using "ñ", because I remember both its code point and its UTF-8 representation, since I always use it for debugging, but the same applies for other non-ASCII, non-alphanumeric number.

Say you have the string "Año" ("year" in Spanish, by the way).

The code points (both in Unicode and iso-8859-1) are:

A: 0x41
ñ: 0xf1
o: 0x6f

If you call escape(), you'll get this:

A: A
ñ: %F1
o: o

"A" and "o" don't need to be encoded. The "ñ" is encoded as "%" plus its code point, which is 0xf1.

But, twitter, facebook, etc, expect UTF-8. 0xf1 is not a valid UTF-8 sequence and should be represented with a 2 bytes sequence. Meaning, "ñ" should be encoded as:

0xC3
0xB1

This is what encodeURIComponent does. It will encode "año" this way:

A: A
ñ: %C3
   %B1
o: o

So, to sum up, instead of this:

 var link:URLRequest = new URLRequest( url + escape(message) );

try this

 var link:URLRequest = new URLRequest( url + encodeURIComponent(message) );

And it should work fine.