VXML 2.0 "expr" attribute of <audio>

The latest publically available version of the VXML 2.0 Working
Draft describes the "expr" attribute of <audio> as

 Dynamically determine the URI to fetch by evaluating this
 ECMAScript expression.

However, multiple examples in the text of the draft (including one
right at the start of 4.1.3) seem to indicate that if "expr" is a
variable containing recorded audio, the recorded audio is supposed
to be played at the point where the <audio> tag is, rather than trying
to treat the recorded audio as a (no doubt ill-formed) URL.

What are the exact rules for when the value of an <audio>'s "expr" is
treated as a dynamically determined URL, and when it's treated as
recorded audio?  What if, for example, "expr" has a value that's a
function call output?  Is it possible to "construct" recorded audio
using ECMAScript functions, and if so, would this be played?  What if
you have some other form input variable as the value of "expr", but
it wasn't filled in with recorded audio?  Will <audio> try to play it or
treat is as a URL?  I hope the way a value is treated is not dependent
on the syntactic form of the "expr" value.

-- 
Ian Sutherland

Voice Laboratory                    E-mail: ian.sutherland@oracle.com
Oracle Corporation                  Work:   312-704-4723
45th Floor, Sears Tower
233 S. Wacker Drive
Chicago, IL  60606  USA

Received on Thursday, 22 August 2002 15:22:33 UTC