Appendix E: VoiceXML Variables

The information contained in the following appendix covers the intricaies of using the different types of VoiceXML variables within your code. Content includes data on variable scoping rules, session variables, shadow variables, and other useful information that will allow you to make the most of your application by utilizing variables to their fullest extent.

Overview

Variable Syntax: Covering variable declaration and proper syntax, this section stands as a good primer for using variables within the VoiceXML language.

Variable Scoping: If you want to specify a particular variable scope rather than relying on a server side language to handle variables, then you will want to check out this scetion which covers declaration, syntax, and the available types of scoped variables.

Session Variables: Covering the application and session shadow variables, this subsection will let you hit the ground running when you want to utilize these internal, 'core' call and recognition values.

ANNOTATIONS: EXISTING POSTS

moshe

4/18/2006 9:16 AM (EDT)

Variables that are passed to VoiceXML scripts can't be accessed using the script alone. For example, if a CCXML calls a VoiceXML script using <dialogstart namelist="foo"/>, the VoiceXML script simply will not see "foo." That's because "foo" is part of the URL and is not passed into the script.

To access a variable passed to a VoiceXML script via a CCXML <dialogstart>, a VoiceXML <submit>, or some other method, you have to use server-side tricks. That is, you have to use some server-side interpreter that alters the VoiceXML script, such as PHP or CGI. See http://www.voicexmlguide.com/qs_vars.htm for details.

mikethompson

4/18/2006 12:18 PM (EDT)

Hey Moshe,

You will undoubtedly be glad to hear this...

There is a way to get access to the CCXML dialogstart ("namelist") variables. They are made available in the VoiceXML 'session.connection.ccxml' name space, as defined in 'http://www.w3.org/TR/2005/WD-ccxml-20050629/#VoiceXMLIntegration'.

In other words, we can now access CCXML namelist vars passed to a VoiceXML dialog without server-side scripting.

An example application demonstrating how to accesses all values in the 'session.connection.ccxml' object is:
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<?xml version="1.0" encoding="UTF-8" ?>
<vxml version="2.1" xmlns:voxeo="http://community.voxeo.com/xmlns/ vxml">
<form id="CCXMLVars">
<block>
<log expr="'session.connection.ccxml == ' + session.connection.ccxml"/>
<log expr="'session.connection.ccxml.sessionid == ' + session.connection.ccxml.sessionid"/>
<log expr="'session.connection.ccxml.dialogid == ' + session.connection.ccxml.dialogid"/>
<log expr="'session.connection.ccxml._ioprocessors == ' + session.connection.ccxml._ioprocessors"/>
<log expr="'session.connection.ccxml._ioprocessors.basichttp == ' + session.connection.ccxml._ioprocessors.basichttp"/>
<log expr="'session.connection.ccxml._url == ' + session.connection.ccxml._url"/>
<log expr="'session.connection.ccxml.namelist == ' + session.connection.ccxml.namelist"/>
<log expr="'session.connection.ccxml.namelist.length == ' + session.connection.ccxml.namelist.length"/>
<foreach item="value" array="session.connection.ccxml.namelist">
<log expr="'foreach keys == ' + value"/>
</foreach>

<log expr="'session.connection.ccxml.values == ' + session.connection.ccxml.values"/>
<log expr="'session.connection.ccxml.values.a == ' + session.connection.ccxml.values.a"/>
<log expr="'session.connection.ccxml.values.b == ' + session.connection.ccxml.values.b"/>
<log expr="'session.connection.ccxml.values.c == ' + session.connection.ccxml.values.c"/>
<log expr="'session.connection.ccxml.values.d == ' + session.connection.ccxml.values.d"/>
</block>
</form>
</vxml>
__________________________________

Hope this helps,
Mike Thompson
Voxeo Extreme Support

moshe

4/18/2006 12:48 PM (EDT)

Excellent improvement!

Now, for a bonus comment -- this doesn't seem to be documented Appendix H under the W3C properties.

MattHenry

4/18/2006 1:18 PM (EDT)

Hiya Moshe,

I'm not sure what it is that you are saying here...are you referring to the session variables not being listed in the VXML docs? Assuming that I am interpreting you correctly, I'd think that I can add this to our "VoiceXML variables" section of the documentation, or perhaps even include this code sample as part of a full-blown tutorial in both the VXML and CCXML docsets.

~Matt

Prophecy VXML Porting Guide

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