VoiceXML 2.1 Development Guide

<help> element

The help element provides a syntactic shorthand for <catch event=”help”>. This element is used as an error handler for the help event which is contained in the Universal Grammar of any voiceXML application. Transitioning elements and prompts to assist the caller are usually nested within the help tags.

usage

attributes

cond	Data Type: CDATA	Default: Optional (true)
	The cond attribute specifies a Boolean expression, which must equate to ‘true’ in order for the content to be visited and executed. Any standard ECMAScript Boolean value is valid for this attribute.
count	Data Type: CDATA	Default: Optional
	The count attribute allows the developer fine grained control over event handling upon multiple event occurrences. When an event is thrown for the first time, the catch element with a count of 1 will be executed. Upon the second instance of the same event, the FIA will look for a catch handler with a count value of 2, if one exists, otherwise, it will simply execute the catch handler with the count of 1 again.

shadow variables

_event

The _event shadow variable equates to a string specifying the event name that caused the exception, thereby making it available for the developer to log or submit the resultant exception/error to a database, or to save it to another local variable to get an application ‘error report’.

parents

children

code samples

<Help count-cond> sample

<?xml version="1.0" encoding="UTF-8"?>

<vxml version = "2.1">

<meta name="author" content="Matthew Henry"/>
<meta name="copyright" content="2005 voxeo corporation"/>
<meta name="maintainer" content="YOUR_EMAIL@HERE.COM"/>

<property name="universals" value="help"/>

<form id="F1">


<property name="universals" value="help"/>

<field name="F_1">
<grammar type="text/gsl"> [(slappy white)]</grammar>
<prompt> say help here.</prompt>

<help count="1" cond="false">
<prompt> since the condition is set to false, this handler will be skipped</prompt>
</help>

<help count="1" cond="true">
<prompt> this is the first occurance of the help event. say help again.</prompt>
</help>

<help count="2" cond="true">
<prompt> this is the second occurance of the help event. goodbye.</prompt>
<disconnect/>
</help>

</field>

<filled>
<prompt>why did you fill the field, you dummy?</prompt>
</filled>

</form>

</vxml>

<Help-shadowvariables> sample

<?xml version="1.0" encoding="UTF-8"?>

<vxml version = "2.1">

<meta name="author" content="Matthew Henry"/>
<meta name="copyright" content="2005 voxeo corporation"/>
<meta name="maintainer" content="YOUR_EMAIL@HERE.COM"/>


<property name="universals" value="help"/>

<help>
<prompt>

The message is <value expr="_message"/>.

The event is <value expr="_event"/>.
</prompt>
</help>

<form id="F1">

<field name="F_1">
<grammar type="text/gsl"> [dummy]</grammar>

<prompt>
Say help to check out the shadow variable values.
</prompt>

<filled>
<prompt>
You really shouldnt have said dummy, you dummy.
</prompt>
</filled>

</field>

</form>

</vxml>

additional links

W3C 2.0 Specification

ANNOTATIONS: EXISTING POSTS

punkin

6/15/2009 7:04 PM (EDT)

<property name="universals" value="help"/>

Do I really need to enable "help"? It works as expected without this <property> tag.

VoxeoDante

6/15/2009 7:23 PM (EDT)

Hello Punkin,

While the universal may be turned on by default on the Prophecy platform at this time, this is a platform dependent feature and is not required by the spec. In order to best comply with the specification and to help ensure a platform change does not affect the operation of the application I would recommend turning it on.

Please let us know if there are any further questions.

Cheers,
Dante Vitulano
Voxeo Corporation