Robust solution to illegal XML characters PHP/AS

[brutfood]

It's a common question how to encode illegal XML characters such as <, > inside XML. And the experts always tell us to enclose them inside CDATA...

<mytag>
<![CDATA[
some illegal < > characters.
]]>
</mytag>

But is that the whole story? What if the string enclosed by CDATA contained the ]]> characters? What if I inserted some XML of my own? This would confuse the E4X parser, wouldn't it?

My particular situation is generating XML in PHP, and parsing it in actionscript. Is there a convention to encoding the sting contained within CDATA... and if so, why don't we just encode and decode to replace illegal XML characters... why do we use CDATA at all?

Or have I got it wrong?

[FlashProfessor]

If you wanted to use the string "]]>" inside of CDATA then you should write the characters in HTML code.

Here is a list of some of these special HTML characters: http://www.tedmontgomery.com/tutorial/htmlchrc.html

If you used XML tags inside of CDATA it will just be rendered out as a string.