I am using the Radius Tag System (from the RadiantCMS) for a content engine in my current applciation. Everything has worked really well, but now I am experiencing issues when using FBML inside my content.
When I supply a tags like the following to my template:
<fb:profile-pic uid="loggedinuser" size="square"></fb:profile-pic>
Radiant gets confused, incorrectly parsing the close tag and outputting:
<fb:profile-pic uid="loggedinuser" size="square"> /fb:profile-pic>
… which in turn breaks the FBML parsing engine.
I am not using the fb prefix for Radius, so there is no clash, and indeed, I can get many of the tags to work by using the self-closing format:
<fb:profile-pic uid="loggedinuser" size="square"/>
Self-closing is fine in many cases, but being able to provide content for a tag means that there is content visible while the Facebook connect engine loads.
A quick analysis showed, that Radius has a problem with closing tags that contain namespaces. This is in no way a Facebook only problem.