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Request for clarification over VXML 2.0 w.r.t. handling of undefined variables

From: Guillaume Berche <guillaume.berche@eloquant.com>
Date: Tue, 13 Jul 2004 10:12:23 +0200
To: <www-voice@w3.org>
Message-ID: <ELEGLIHGLLIBFPCIGAKGIEGLEBAA.guillaume.berche@eloquant.com>


I would like to request a clarification of the VXML 2.0 specification with
respect to handling of declared but unassigned variables which therefore
have the ECMAScript undefined value:

What is the expected behavior of elements such as <value> or <log>
referencing an expression resolving into a declared but undefined value in
their expr attribute?

Similarly, what is the expected behavior of elements such as <submit>,
<subdialog> referencing a declared but undefined variable in their namelist

Should the ECMAScript default conversion to the "undefined" string apply, or
should an error.semantic event be thrown?

The VBWG rejected one suggestion (CR5-3) to silently ignore value with
undefined expr (in a similar way that audio with undefined expr are
ignored), but did not explicitly precise the expected behavior.

I would suggest to precise the default ECMAScript conversion applies, and
therefore to add the following fragment to the end of section "5.1.1
Declaring Variables":

"When a variable with an undefined value is used within an expression, the
default ECMAScript promotion to the String format 'undefined' is used unless
specified otherwise (such as in the audio element). For instance, when the
<value> element is used with an undefined value, the 'undefined' string is
then synthetized. Similar behavior is applied onto the submit and subdialog
elements specifying undefined variables in their namelist."

In addition, section "5.2.6 Event Types" states" should be corrected from

A run-time error was found in the VoiceXML document, e.g. substring bounds
error, or an undefined variable was referenced."


A run-time error was found in the VoiceXML document, e.g. substring bounds
error, or an **undeclared** variable was referenced."

Could this type of requests be handled through the errata page at
http://www.w3.org/2004/03/voicexml20-errata.html ?

Thanks in advance for your help and best regards,

Guillaume Berche.

Guillaume Berche
Eloquant, ZA Le malvaisin
38240 Le Versoud, France
Received on Tuesday, 13 July 2004 04:36:56 UTC

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