W3C

Voice Extensible Markup Language (VoiceXML) 2.1

W3C Candidate Recommendation 13 June 2005

This version:
http://www.w3.org/TR/2005/CR-voicexml21-20050613/
Latest version:
http://www.w3.org/TR/voicexml21/
Previous version:
http://www.w3.org/TR/2004/WD-voicexml21-20040728/
Editors:
Matt Oshry, Tellme Networks (Editor-in-Chief)
RJ Auburn, Voxeo Corporation
Paolo Baggia, Loquendo
Michael Bodell, Tellme Networks
David Burke, Voxpilot Ltd.
Daniel C. Burnett, Invited Expert
Emily Candell, Comverse
Hakan Kilic, Scansoft
Scott McGlashan, Hewlett-Packard
Alex Lee, VoiceGenie
Brad Porter, Tellme Networks
Ken Rehor, Vocalocity

A non-normative version of this document showing changes made since the previous draft is also available.


Abstract

VoiceXML 2.1 specifies a set of features commonly implemented by Voice Extensible Markup Language platforms. This specification is designed to be fully backwards-compatible with VoiceXML 2.0 [VXML2]. This specification describes only the set of additional features.

Status of this Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This is the 13 June 2005 W3C Candidate Recommendation of "VoiceXML Version 2.1". W3C publishes a technical report as a Candidate Recommendation to indicate that the document is believed to be stable and to encourage implementation by the developer community. Candidate Recommendation status is described in section 7.1.1 of the Process Document. Comments can be sent until 11 July 2005.

Publication as a Candidate Recommendation does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document has been produced as part of the Voice Browser Activity (activity statement), following the procedures set out for the W3C Process. The authors of this document are members of the Voice Browser Working Group (W3C Members only).

This document was produced under the 5 February 2004 W3C Patent Policy. The Working Group maintains a public list of patent disclosures relevant to this document; that page also includes instructions for disclosing [and excluding] a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) with respect to this specification should disclose the information in accordance with section 6 of the W3C Patent Policy.

This document is for public review, and comments and discussion are welcomed on the (archived) public mailing list <www-voice@w3.org>.

This document is based upon the VoiceXML Version 2.1 Last Call Working Draft of 28 July 2004 and feedback received during the review period (see the Disposition of Comments document). The Voice Browser Working Group (member-only link) believes that this specification addresses its requirements and all Last Call issues.

The entrance criteria to the Proposed Recommendation phase require at least two independently developed interoperable implementations of each required feature, and at least one or two implementations of each optional feature depending on whether the feature's conformance requirements have an impact on interoperability. Detailed implementation requirements and the invitation for participation in the Implementation Report are provided in the Implementation Report Plan. Note, this specification already has significant implementation experience that will soon be reflected in its Implementation Report. We expect to meet all requirements of that report within the Candidate Recommendation period closing 11 July 2005.

In this document, the key words "must", "must not", "required", "shall", "shall not", "should", "should not", "recommended", "may", and "optional" are to be interpreted as described in [RFC2119] and indicate requirement levels for compliant VoiceXML implementations. The sections in the main body of this document are normative unless otherwise specified. The appendices in this document are informative unless otherwise indicated explicitly.

Table of Contents

1 Introduction
    1.1 Elements Introduced or Enhanced in VoiceXML 2.1
2 Referencing Grammars Dynamically
3 Referencing Scripts Dynamically
4 Using <mark> to Detect Barge-in During Prompt Playback
5 Using <data> to Fetch XML Without Requiring a Dialog Transition
    5.1 <data> Fetching Properties
6 Concatenating Prompts Dynamically Using <foreach>
7 Recording User Utterances While Attempting Recognition
    7.1 Specifying the Media Format of Utterance Recordings
8 Adding namelist to <disconnect>
9 Adding type to <transfer>
    9.1 Consultation Transfer
    9.2 Consultation Transfer Errors and Events
    9.3 Example of a Consultation Transfer

Appendices

A VoiceXML Document Type Definition
B VoiceXML Schema
C Conformance
    C.1 Conforming VoiceXML 2.1 Document
    C.2 Using VoiceXML with other namespaces
    C.3 Conforming VoiceXML 2.1 Processors
D ECMAScript Language Binding for DOM
E References
    E.1 Normative References
    E.2 Other References
    E.3 Acknowledgements
F Summary of changes since the Last Call Working Draft


1 Introduction

The popularity of VoiceXML 2.0 [VXML2] spurred the development of numerous voice browser implementations early in the specification process. [VXML2] has been phenomenally successful in enabling the rapid deployment of voice applications that handle millions of phone calls every day. This success has led to the development of additional, innovative features that help developers build even more powerful voice-activated services. While it was too late to incorporate these additional features into [VXML2], the purpose of VoiceXML 2.1 is to formally specify the most common features to ensure their portability between platforms and at the same time maintain complete backwards-compatibility with [VXML2].

This document defines a set of 8 commonly implemented additional features to VoiceXML 2.0 [VXML2].

1.1 Elements Introduced or Enhanced in VoiceXML 2.1

The following table lists the elements that have been introduced or enhanced in VoiceXML 2.1.

Table 1: Elements Introduced or Enhanced in VoiceXML 2.1
ElementPurposeSectionNew/Enhanced
<data>Fetches arbitrary XML data from a document server.5New
<disconnect>Disconnects a session.8Enhanced
<grammar>References a speech recognition or DTMF grammar.2Enhanced
<foreach>Iterates through an ECMAScript array.6New
<mark>Declares a bookmark in a sequence of prompts.4Enhanced
<property>Controls platform settings.5.1, 7Enhanced
<script>References a document containing client-side ECMAScript.3Enhanced
<transfer>Transfers the user to another destination.9Enhanced

2 Referencing Grammars Dynamically

As described in section 3.1 of [VXML2], the <grammar> element allows the specification of a speech recognition or DTMF grammar. VoiceXML 2.1 extends the <grammar> element to support the following additional attribute:

Table 1: <grammar> Attributes
srcexpr Equivalent to src, except that the URI is dynamically determined by evaluating the given ECMAScript expression in the current scope (e.g. the current form item). The expression must be evaluated each time the grammar needs to be activated. If srcexpr cannot be evaluated, an error.semantic event is thrown.

Exactly one of "src", "srcexpr", or an inline grammar must be specified; otherwise, an error.badfetch event is thrown.

The following example demonstrates capturing a street address. The first field requests a country, the second field requests a city, and the third field requests a street. The grammar for the second field is selected dynamically using the result of the country field. The grammar for the third field is selected dynamically using the result of the city field.

<?xml version="1.0" encoding="UTF-8"?>
<vxml xmlns="http://www.w3.org/2001/vxml" 
  version="2.1">

  <form id="get_address">
    <field name="country">
      <grammar type="application/srgs+xml" src="country.grxml"/>
      <prompt>Say a country.</prompt>
    </field>

    <field name="city">
      <grammar type="application/srgs+xml" srcexpr="country + '/cities.grxml"/>
      <prompt>What city in <value expr="country"/>.</prompt>
    </field>

    <field name="street">
      <grammar type="application/srgs+xml" srcexpr="country + '/' + city + '/streets.grxml'"/>
      <prompt> What street in <value expr="city"/> are you looking for? </prompt>
    </field>

    <filled>
      <prompt> 
       You chose 
       <value expr="street"/> 
       in 
       <value expr="city"/> 
       <value expr="country"/>
      </prompt>
      <exit/>
    </filled>
  </form>
</vxml>

3 Referencing Scripts Dynamically

As described in section 5.3.12 of [VXML2], the <script> element allows the specification of a block of client-side scripting language code, and is analogous to the [HTML4] <SCRIPT> element. VoiceXML 2.1 extends the <script> element to support the following additional attribute:

Table 2: <script> Attributes
srcexpr Equivalent to src, except that the URI is dynamically determined by evaluating the given ECMAScript expression. The expression must be evaluated each time the script needs to be executed. If srcexpr cannot be evaluated, an error.semantic event is thrown.

Exactly one of "src", "srcexpr", or an inline script must be specified; otherwise, an error.badfetch event is thrown.

The following example retrieves a script from a URI that is composed at run-time using the variable scripts_baseuri.

<?xml version="1.0" encoding="UTF-8"?>
<vxml xmlns="http://www.w3.org/2001/vxml" 
  version="2.1">

  <var name="scripts_baseuri" expr="'http://www.example.org/'"/>

  <form>
    <script srcexpr="scripts_baseuri + 'lib/util.js'"/>
  </form>
</vxml>

4 Using <mark> to Detect Barge-in During Prompt Playback

As described in section 3.3.2 of [SSML], the <mark> element places a marker into the text/tag sequence. An SSML processor must either allow the VoiceXML interpreter to retrieve or must inform the interpreter when a <mark> is executed during audio output.

[SSML] defines a single attribute, name, on the <mark> element, allowing the programmer to name the mark. VoiceXML 2.1 extends the <mark> element to support the following additional attribute:

Table 3: <mark> Attributes
nameexprAn ECMAScript expression which evaluates to the name of the mark. If nameexpr cannot be evaluated, an error.semantic event is thrown.

Exactly one of "name" and "nameexpr" must be specified; otherwise, an error.badfetch event is thrown.

As described in section 4.1.1 of [VXML2], the <mark> element is permitted in conforming VoiceXML documents, but [VXML2] does not specify a standard way for VoiceXML processors to access <mark> element information. Processors of conforming VoiceXML 2.1 documents must set the following two properties on the application.lastresult$ object whenever the application.lastresult$ object is assigned (e.g. a <link> is matched) and a <mark> has been executed.

Table 4: <mark>-related application.lastresult$ properties
markname The name of the mark last executed by the SSML processor before barge-in occurred or the end of audio playback occurred. If no mark was executed, this variable is undefined.
marktime The number of milliseconds that elapsed since the last mark was executed by the SSML processor until barge-in occurred or the end of audio playback occurred. If no mark was executed, this variable is undefined.

When these properties are set on the application.lastresult$ object, if an input item (as defined in section 2.3 of [VXML2]) has also been filled and has its shadow variables assigned, the interpreter must also assign markname and marktime shadow variables, the values of which equal the corresponding properties of the application.lastresult$ object.

When a <mark> is executed during the flushing of the prompt queue as a result of encountering a fetchaudio, the application.lastresult$ object should not be modified and no shadow variables should be assigned.

The following example establishes marks at the beginning and at the end of an advertisement. In the <filled>, the code checks which mark, if any, was last executed when bargein occurred. If the "ad_start" mark is executed but "ad_end" is not, the code checks that at least 5 seconds of the advertisement has been played and sets the played_ad variable appropriately.

<?xml version="1.0" encoding="UTF-8"?>
<vxml xmlns="http://www.w3.org/2001/vxml" 
  version="2.1">

  <var name="played_ad" expr="false"/>

  <form>   
    <field name="team">
      <prompt>
        <mark name="ad_start"/>
        Baseball scores brought to you by Elephant Peanuts.
        There's nothing like the taste of fresh roasted peanuts.
        Elephant Peanuts. Ask for them by name.
        <mark name="ad_end"/>
        <break time="500ms"/>
        Say the name of a team. For example, say Boston Red Sox.
      </prompt>
  
      <grammar type="application/srgs+xml" src="teams.grxml"/>
  
      <filled>
        <if cond="typeof(team$.markname) == 'string' &amp;&amp;
           (team$.markname=='ad_end' || 
           (team$.markname=='ad_start' &amp;&amp;
              team$.marktime &gt;= 5000))">
          <assign name="played_ad" expr="true"/>
        <else/>
          <assign name="played_ad" expr="false"/>
        </if>
      </filled>
  
    </field>
  </form>   

</vxml>

5 Using <data> to Fetch XML Without Requiring a Dialog Transition

The <data> element allows a VoiceXML application to fetch arbitrary XML data from a document server without transitioning to a new VoiceXML document. The XML data fetched by the <data> element is bound to ECMAScript through the named variable that exposes a read-only subset of the W3C Document Object Model (DOM).

Attributes of <data> are:

Table 5: <data> Attributes
srcThe URI specifying the location of the XML data to retrieve.
nameThe name of the variable that exposes the DOM.
srcexprLike src, except that the URI is dynamically determined by evaluating the given ECMAScript expression when the data needs to be fetched. If srcexpr cannot be evaluated, an error.semantic event is thrown.
methodThe request method: get (the default) or post.
namelist The list of variables to submit. By default, no variables are submitted. If a namelist is supplied, it may contain individual variable references which are submitted with the same qualification used in the namelist. Declared VoiceXML and ECMAScript variables can be referenced.
enctypeThe media encoding type of the submitted document. The default is application/x-www-form-urlencoded. Interpreters must also support multipart/form-data and may support additional encoding types.
fetchaudioSee Section 6.1 of [VXML2]. This defaults to the fetchaudio property described in Section 6.3.5 of [VXML2].
fetchhint See Section 6.1 of [VXML2]. This defaults to the datafetchhint property described in Section 5.1.
fetchtimeoutSee Section 6.1 of [VXML2]. This defaults to the fetchtimeout property described in Section 6.3.5 of [VXML2].
maxage See Section 6.1 of [VXML2]. This defaults to the datamaxage property described in Section 5.1.
maxstale See Section 6.1 of [VXML2]. This defaults to the datamaxstale property described in Section 5.1.

Exactly one of "src" or "srcexpr" must be specified; otherwise, an error.badfetch event is thrown. If the content cannot be retrieved, the interpreter throws an error as specified for fetch failures in Section 5.2.6 of [VXML2].

Platforms should support parsing XML data into a DOM. If an implementation does not support DOM, the name attribute must not be set, and any retrieved content must be ignored by the interpreter. If the name attribute is present, these implementations will throw error.unsupported.data.name.

If the name attribute is present, and the returned document is XML, the VoiceXML interpreter must expose the retrieved content via a read-only subset of the DOM as specified in Appendix D. An interpreter may support additional data formats by recognizing additional media types. If an interpreter receives a document in a data format that it does not understand, or the data is not well-formed as defined by the specification of that format, the interpreter throws error.badfetch. If the media type of the retrieved content is "text/xml" but the content is not well-formed XML, the interpreter throws error.badfetch.

Like the <var> element, the <data> element can occur in executable content or as a child of <form> or <vxml>. In addition, it shares the same scoping rules as the <var> element. If a <data> element has the same name as a variable already declared in the same scope, the variable is assigned a reference to the DOM exposed by the <data> element.

If use of the DOM causes a DOMException to be thrown, but the DOMException is not caught by an ECMAScript catch handler, the VoiceXML interpreter throws error.semantic.

Like the <submit> element, when an ECMAScript variable is submitted to the server its value is first converted into a string before being submitted. If the variable is an ECMAScript Object the mechanism by which it is submitted is not currently defined. If a <data> element's namelist contains a variable which references recorded audio but does not contain an enctype of multipart/form-data, the behavior is not specified. It is probably inappropriate to attempt to URL-encode large quantities of data.

In the examples that follow, the XML document fetched by the <data> element is in the following format:

<?xml version="1.0" encoding="UTF-8"?>
<quote>
  <ticker>F</ticker>
  <name>Ford Motor Company</name>
  <change>1.00</change>
  <last>30.00</last>
</quote>

The following example assigns the value of the "last" element to the ECMAScript variable "price":

<data name="quote" src="quote.xml"/> 
<script><![CDATA[
  var price = quote.documentElement.getElementsByTagName("last").item(0).firstChild.data;
]]></script>

The data is fetched when the <data> element is executed according to the caching rules established in Section 6.1 of [VXML2].

Before exposing the data in an XML document referenced by the <data> element via the DOM, the interpreter should check that the referring document is allowed to access the data. If access is denied the interpreter must throw error.noauthorization.

Note:

One strategy commonly implemented in voice browsers to control access to data is the "access-control" processing instruction described in the WG Note: Authorizing Read Access to XML Content Using the <?access-control?> Processing Instruction 1.0 [DATA_AUTH].

The following example retrieves a stock quote in one dialog, caches the DOM in a variable at document scope, and uses the DOM to playback the quote in another dialog.

<?xml version="1.0" encoding="UTF-8"?>
<vxml xmlns="http://www.w3.org/2001/vxml" 
  version="2.1">
  <var name="quote"/>
  <var name="ticker" expr="'f'"/>

  <form id="get_quote">
     <block>
        <data name="quote" srcexpr="'http://www.example.org/getquote?ticker=' + ticker"/>
        <assign name="document.quote" expr="quote.documentElement"/>
        <goto next="#play_quote"/>         
     </block>
  </form>

  <form id="play_quote">

     <script><![CDATA[
     // retrieve the value contained in the node t from the DOM exposed by d
     function GetData(d, t, nodata)
     {
        try {
           return d.getElementsByTagName(t).item(0).firstChild.data;
        }
        catch(e)
        {
           // the value could not be retrieved, so return this instead
           return nodata;
        }
     }
     ]]></script>

     <block>
        <!-- retrieve the change in the stock's value -->
        <var name="change" expr="GetData(quote, 'change', 0)"/>
        <var name="last" expr="GetData(quote, 'last', 0)"/>
        <var name="last_parts" expr="last.split('.')"/>

        <!--play the company name -->
        <audio expr="ticker + '.wav'"><value expr="GetData(quote, 'name', 'unknown')"/></audio>
        <!-- play 'unchanged, 'up', or 'down' based on zero, positive, or negative change -->
        <if cond="change == 0">
           <audio src="unchanged_at.wav"/>
        <else/>
           <if cond="change &gt; 0">
              <audio src="up.wav"/>
           <else/> <!-- negative -->
              <audio src="down.wav"/>
           </if>
           <audio src="by.wav"/>
           <!-- play change in value as positive number -->
           <audio expr="Math.abs(change) + '.wav'"><value expr="Math.abs(change)"/></audio>
           <audio src="to.wav"/>
        </if>
        <!-- play the current price per share -->
        <audio expr="last_parts[0] + '.wav'"><value expr="last_parts[0]"/></audio>
        <if cond="Number(last_parts[1]) &gt; 0">
           <audio src="point.wav"/>
           <audio expr="last_parts[1] + '.wav'"><value expr="last_parts[1]"/></audio>
        </if>
     </block>
  </form>
</vxml>

5.1 <data> Fetching Properties

These properties pertain to documents fetched by the <data> element.

Table 6: <data> Fetching Properties
datafetchhint Tells the platform whether or not data documents may be pre-fetched. The value is either prefetch (the default), or safe.
datamaxage Tells the platform the maximum acceptable age, in seconds, of cached documents. The default is platform-specific.
datamaxstale Tells the platform the maximum acceptable staleness, in seconds, of expired cached data documents. The default is platform-specific.

6 Concatenating Prompts Dynamically Using <foreach>

The <foreach> element allows a VoiceXML application to iterate through an ECMAScript array and to execute the content contained within the <foreach> element for each item in the array.

Attributes of <foreach> are:

Table 7: <foreach> Attributes
arrayAn ECMAScript expression that must evaluate to an array; otherwise, an error.semantic event is thrown.
itemThe variable that stores each array item upon each iteration of the loop. A new variable will be declared if it is not already defined within the parent's scope.

Both "array" and "item" must be specified; otherwise, an error.badfetch event is thrown.

The <foreach> element can occur in executable content and as a child of <prompt>.

The following example calls a user-defined function GetMovieList that returns an ECMAScript array. The array is assigned to the variable named 'prompts'. Upon entering the <field>, if a noinput or a nomatch event occurs, the VoiceXML interpreter reprompts the user by executing the second <prompt>. The second <prompt> executes the <foreach> element by iterating through the ECMAScript array 'prompts' and assigning each array element to the variable 'thePrompt'. Upon each iteration of the <foreach>, the interpreter executes the contained <audio> and <break> elements.

<?xml version="1.0" encoding="UTF-8"?>
<vxml xmlns="http://www.w3.org/2001/vxml"
  version="2.1">

  <script src="movies.js"/>

  <form id="pick_movie">
  
    <!-- 
    GetMovieList returns an array of objects
      with properties audio and tts.
      The size of the array is undetermined until runtime.
    -->  
    <var name="prompts" expr="GetMovieList()"/>

    <field name="movie">
      <grammar type="application/srgs+xml" src="movie_names.grxml"/>
  
      <prompt>Say the name of the movie you want.</prompt>
  
      <prompt count="2">
        <audio src="prelist.wav">When you hear the name of the movie you want, just say it.</audio>
        <foreach item="thePrompt" array="prompts">
          <audio expr="thePrompt.audio"><value expr="thePrompt.tts"/></audio>
          <break time="300ms"/>
        </foreach>
      </prompt>
  
      <noinput>
        I'm sorry. I didn't hear you.
        <reprompt/>
      </noinput>
  
      <nomatch>
        I'm sorry. I didn't get that.
        <reprompt/>
      </nomatch>
  
    </field>
  </form>
</vxml>

The following is a contrived implementation of the user-defined GetMovieList function:

function GetMovieList()
{
  var movies = new Array(3);
  movies[0] = new Object();
  movies[0].audio = "godfather.wav"; movies[0].tts = "the godfather";
  movies[1] = new Object();
  movies[1].audio = "high_fidelity.wav"; movies[1].tts = "high fidelity";
  movies[2] = new Object();
  movies[2].audio = "raiders.wav"; movies[2].tts = "raiders of the lost ark";
  
  return movies;
}

When the interpreter queues the second <prompt>, it expands the <foreach> element in the previous example to the following:

<audio src="godfather.wav">the godfather</audio>
<break time="300ms"/>
<audio src="high_fidelity.wav">high fidelity</audio>
<break time="300ms"/>
<audio src="raiders.wav">raiders of the lost ark</audio>
<break time="300ms"/>

The following example combines the use of the <mark> and <foreach> elements to more precisely identify which item in a list of movies the user has selected. During each iteration of the <foreach>, the interpreter stores the current item in the array to the variable movie. Upon execution of the <mark> element, the name of the <mark> is set to the current value of the variable movie_idx which is incremented during each iteration of the loop using the <assign> element.

In the <filled>, if the form item variable mov is set to the value "more", indicating the user's desire to hear more detail about the movie name that was played when the user barged in, the code retrieves the index of the desired movie in the movies array from mov$.markname. If barge-in occurred within twenty milliseconds of the mark's execution, the code retrieves the index of the preceding movie under the assumption that the user was slow to react.

<?xml version="1.0" encoding="UTF-8"?>
<vxml xmlns="http://www.w3.org/2001/vxml"
  version="2.1">

  <script src="movies.js"/>

  <form id="list_movies">
    <!-- fetch the current list of movies, and transform them into an array -->
    <data name="domMovies" src="getmovies.cgi"/>
    <var name="movies" expr="GetMovieList(domMovies)"/>
    <var name="movie_idx" expr="0"/>
    <var name="movie_id"/>
  
    <field name="mov">
      <prompt>
        Say the name of the movie.
      </prompt>
  
      <prompt count="2">
        Here's the list of movies. 
        To hear more about a movie, say 'tell me more'.
        <break time="500ms"/>
        <foreach item="movie" array="movies">
          <mark nameexpr="movie_idx"/>
          <audio expr="movie.audio"><value expr="movie.tts"/></audio>
          <break time="500ms"/>
          <assign name="movie_idx" expr="movie_idx+1"/>
        </foreach>
      </prompt>
  
      <grammar type="application/srgs+xml" src="more.grxml"/>
      <grammar type="application/srgs+xml" src="movies.grxml"/>
  
      <catch event="nomatch">
        Sorry. I didn't get that.
        <reprompt/>
      </catch>
  
      <catch event="noinput">
        <reprompt/>
      </catch>
  
      <filled>
        <if cond="'more' == mov">
          <!-- user wants more detail -->
          <!-- assume no mark was executed -->
          <assign name="movie_idx" expr="0"/>
          <if cond="mov$.markname != undefined">
            <!-- alas, a mark was executed, so adjust movie_idx -->
            <if cond="mov$.marktime &lt;= 20">
              <!-- returns the id of the previous movie (or the first) -->
              <assign name="movie_idx" 
                expr="(mov$.markname &lt;= 1 ? 0 : mov$.markname-1)"/>
            <else/>
              <assign name="movie_idx" expr="mov$.markname"/>
            </if>
          </if>          
          <assign name="movie_id" expr="movies[movie_idx].id"/>
        <else/>
          <!-- user said a specific movie -->
          <assign name="movie_id" expr="mov"/>
        </if>
      </filled>    
    </field>

    <!-- 
     Given a movie id, fetch detail, and play it back.
     detail could be in a single wav file or in multiple files.
    -->  
    <block name="play_detail">
      <!-- GetMovieDetail returns an array of objects with properties audio and tts. -->
      <var name="details" expr="GetMovieDetail(domMovies, movie_id)"/>
      <foreach item="chunk" array="details">
        <audio expr="chunk.audio"><value expr="chunk.tts"/></audio>
      </foreach>
    </block>
  
  </form>
</vxml>

The following is a contrived XML document returned by getmovies.cgi. The user-defined GetMovieList and GetMovieDetail functions below are implemented to manipulate the DOM representation of its structure.

<?xml version="1.0" encoding="UTF-8"?>
<movies>
  <movie id="m0010">
    <title>
      <tts>the godfather</tts>
      <wav>godfather.wav</wav>
    </title>
    <details>
    <detail>
      <wav>directors/directed_by.wav</wav>
      <tts>directed by</tts>
    </detail>
    <detail>
      <wav>directors/coppola.wav</wav>
      <tts>francis ford coppola</tts>
    </detail>
    <detail>
      <wav>ratings/rated.wav</wav>
      <tts>rated</tts>
    </detail>
    <detail>
      <wav>ratings/r.wav</wav>
      <tts>r</tts></detail>
    <detail>
      <wav>pauses/300.wav</wav>
      <tts/>
    </detail>
    <detail>
      <wav>synopsis/m0010.wav</wav>
      <tts>a coming of age story about a nice italian boy</tts>
    </detail>
    </details>
  </movie>
  
  <movie id="m0052">
    <title>
      <tts>high fidelity</tts>
      <wav>high_fidelity.wav</wav>
    </title>
    <details>
      <!-- details omitted for the sake of brevity -->
    </details>
  </movie>
  
  <movie id="m0027">
   <title>
     <tts>raiders of the lost ark</tts>
     <wav>raiders.wav</wav>
   </title>
    <details>
      <!-- details omitted for the sake of brevity -->
    </details>
  </movie>
</movies>

The following is an implementation of the user-defined GetMovieList function:

// return an array of user-defined movie objects retrieved from the DOM
function GetMovieList(domMovies) {
  var movies = new Array();
  try {
    var nodeRoot = domMovies.documentElement;
    for (var i = 0; i < nodeRoot.childNodes.length; i++) {
      var nodeChild = nodeRoot.childNodes.item(i);
      if ("movie" != nodeChild.nodeName) {
        continue;
      }
      else {
        var objMovie = new Object(); 
        objMovie.id = nodeChild.getAttribute("id");
        var nodeTitle = GetTitle(nodeChild);
        objMovie.audio = GetWav(nodeTitle);
        objMovie.tts = GetTTS(nodeTitle);
        movies.push(objMovie);
      }
    }
  }
  catch(e) {
    // unable to build movie list
    var objError = new Object();
    objError.audio = "nomovies.wav";
    objError.tts = "sorry. no movies are available."
    details.push(objError);
  }
  return movies;
}

function GetTitle(nodeMovie) {
  return GetChild(nodeMovie, "title");
}

function GetTTS(node) {
  return GetInnerText(GetChild(node, "tts"));
}

function GetWav(node) {
  return GetInnerText(GetChild(node, "wav"));
}

// perform a shallow traversal of the node referenced by parent 
// looking for the named node
function GetChild(parent, name)
{
  var target = null;
  for (var i = 0; i < parent.childNodes.length; i++) {
    var child = parent.childNodes.item(i);
    if (child.nodeName == name) {
      target = child;
      break;
    }
  }
  return target;
}

// Given a node, dig the text nodes out and return them as a string
function GetInnerText(node) {
  var s = "";
  if (null == node) {
    return s;
  }

  for (var i = 0; i < node.childNodes.length; i++) {
    var child = node.childNodes.item(i);
    if (Node.TEXT_NODE == child.nodeType || Node.CDATA_SECTION_NODE == child.nodeType) {
      s += child.data;
    }
    else if (Node.ELEMENT_NODE == child.nodeType) {
      s += GetInnerText(child);
    }
  }
  return s;
}

The following is an implementation of the user-defined GetMovieDetail function:

// get the details about the movie specified by id
function GetMovieDetail(domMovies, id) {
  var details = new Array();
  try {
    var nodeMovie = domMovies.getElementById(id);
    var nodeTitle = GetTitle(nodeMovie);
    var objTitle = new Object();
    objTitle.audio = GetWav(nodeTitle);
    objTitle.tts = GetTTS(nodeTitle);
    details.push(objTitle);
    var nodeDetails = GetChild(nodeMovie, "details");
    for (var i = 0; i < nodeDetails.childNodes.length; i++) {
      var nodeChild = nodeDetails.childNodes.item(i);
      if ("detail" == nodeChild.nodeName) {
        var objDetail = new Object();
        objDetail.audio = GetWav(nodeChild);
        objDetail.tts = GetTTS(nodeChild);
        details.push(objDetail);
      }
    }
  }
  catch(e) {
    // couldn't get movie details
    var objError = new Object();
    objError.audio = "nomovie.wav";
    objError.tts = "sorry. details for that movie are unavailable."
    details.push(objError);
  }

  return details;
}

When the interpreter queues the second <prompt> in the field named "mov", it expands the <foreach> element to the following:

<mark name="0"/>
<audio src="godfather.wav">the godfather</audio>
<break time="300ms"/>
<mark name="1"/>
<audio src="high_fidelity.wav">high fidelity</audio>
<break time="300ms"/>
<mark name="2"/>
<audio src="raiders.wav">raiders of the lost ark</audio>
<break time="300ms"/>

If the user chooses "The Godfather", when the interpreter executes the "play_detail" <block>, it expands the <foreach> element to the following:

<audio src="directors/directed_by.wav">directed by</audio>
<audio src="directors/coppola.wav">francis ford coppola</audio>
<audio src="ratings/rated.wav">rated</audio>
<audio src="ratings/r.wav">r</audio>
<audio src="pauses/300.wav"/>
<audio src="synopsis/m0010.wav">a coming of age story about a nice italian boy</audio>

7 Recording User Utterances While Attempting Recognition

Several elements defined in [VXML2] can instruct the interpreter to accept user input during execution. These elements include <field>, <initial>, <link>, <menu>, <record>, and <transfer>. VoiceXML 2.1 extends these elements to allow the interpreter to conditionally enable recording while simultaneously gathering input from the user.

To enable recording during recognition, set the value of the recordutterance property to true. If the recordutterance property is set to true in the current scope, the following three shadow variables are set on the application.lastresult$ object whenever the application.lastresult$ object is assigned (e.g. when a <link> is matched):

Table 8: recordutterance-related shadow variables
recording The variable that stores a reference to the recording, or undefined if no audio is collected. Like the input item variable associated with a <record> element as described in section 2.3.6 of [VXML2], the implementation of this variable may vary between platforms.
recordingsize The size of the recording in bytes, or undefined if no audio is collected.
recordingduration The duration of the recording in milliseconds, or undefined if no audio is collected.

When these properties are set on the application.lastresult$ object, if an input item (as defined in section 2.3 of [VXML2]) has also been filled and has its shadow variables assigned, the interpreter must also assign recording, recordingsize, and recordingduration shadow variables for these input items, the values of which equal the corresponding properties of the application.lastresult$ object. For example, in the case of <link> and <menu>, since no input item has its shadow variables set, the interpreter only sets the application.lastresult$ properties.

Support for this feature is optional on <record>, and <transfer>. Platforms that support it set the aforementioned shadow variables on the associated form item variable and the corresponding properties on the application.lastresult$ object when the recordutterance property is set to true in an encompassing scope.

Like recordings created using the <record> tag, utterance recordings can be played back using the expr attribute on <audio>.

Like recordings created using the <record> tag, utterance recordings can be submitted to a document server via HTTP POST using the namelist attribute of the <submit>, <data>, and <subdialog> elements. The enctype attribute must be set to "multipart/form-data", and the method attribute must be set to "post". To provide flexibility in the naming of the variable that is submitted to the document server, the interpreter must allow the utterance recording to be assigned to and posted via any valid ECMAScript variable.

In the following example, the dialog requests a city and state from the user. On the third recognition failure, the recording of the user's utterance is submitted to a document server.

<?xml version="1.0" encoding="UTF-8"?>
<vxml xmlns="http://www.w3.org/2001/vxml" 
  version="2.1">
  <form>
    <property name="recordutterance" value="true"/>

    <field name="city_state">
     <prompt>
      Say a city and state.
     </prompt>

     <grammar type="application/srgs+xml" src="citystate.grxml"/>

     <nomatch>
      I'm sorry. I didn't get that.
      <reprompt/>
     </nomatch>

     <nomatch count="3">
        <var name="the_recording" 
          expr="application.lastresult$.recording"/>
        <submit method="post" 
          enctype="multipart/form-data" 
          next="upload.cgi"
          namelist="the_recording"/>
     </nomatch>
    </field>  
  </form>
</vxml>

7.1 Specifying the Media Format of Utterance Recordings

To specify the media format of the resulting recording, set the recordutterancetype property. Platforms must support the audio file formats specified in Appendix E of [VXML2]. Other formats may also be supported. The recordutterancetype property defaults to a platform-specific format which should be one of the required formats. If an unsupported media format is encountered during recognition, the platform throws an error.unsupported.format event which specifies the unsupported media format in its message variable. Note that the recordutterancetype property does not affect the <record> element.

8 Adding namelist to <disconnect>

As described in section 5.3.11 of [VXML2], the <disconnect> element causes the interpreter context to disconnect from the user. VoiceXML 2.1 extends the <disconnect> element to support the following attribute:

Table 9: <disconnect> Attributes
namelist Variable names to be returned to the interpreter context. The default is to return no variables; this means the interpreter context will receive an empty ECMAScript object. If an undeclared variable is referenced in the namelist, then an error.semantic is thrown (5.1.1 of [VXML2]).

The <disconnect> namelist and the <exit> namelist are processed independently. If the interpreter executes both a <disconnect> namelist and an <exit> namelist, both sets of variables are available to the interpreter context. The precise mechanism by which these variables are made available to the interpreter context is platform specific.

9 Adding type to <transfer>

As described in section 2.3.7 of [VXML2], the <transfer> element directs the interpreter to connect the caller to another entity. VoiceXML 2.1 extends the <transfer> element to support the following additional attribute:

Table 10: <transfer> Attributes
type The type of transfer. The value can be "bridge", "blind", or "consultation".

Exactly one of "bridge" or "type" may be specified; otherwise an error.badfetch event is thrown.

As specified in 2.3.7 of [VXML2], the <transfer> element is optional, though platforms should support it. Platforms that support <transfer> may support any combination of bridge, blind, or consultation transfer types.

If the value of the type attribute is set to "bridge", the interpreter's behavior must be identical to its behavior when the value of the bridge attribute is set to "true". If the value of the type attribute is set to "blind", the interpreter's behavior must be identical to its behavior when the bridge attribute is set to "false". The behavior of the bridge attribute is fully specified in section 2.3.7 of [VXML2]. If the type attribute is specified and the bridge attribute is absent, the value of the type attribute takes precedence over the default value of the bridge attribute.

The bridge attribute is maintained for backwards compatiblity with [VXML2]. Since all of the functionality of the bridge attribute has been incorporated into the type attribute, developers are encouraged to use the type attribute on platforms that implement it.

The connecttimeout attribute of <transfer> applies if the type attribute is set to "bridge" or "consultation".

The maxtime attribute of <transfer> applies if the type attribute is set to "bridge".

9.1 Consultation Transfer

The consultation transfer is similar to a blind transfer except that the outcome of the transfer call setup is known and the caller is not dropped as a result of an unsuccessful transfer attempt. When performing a consultation transfer, the platform monitors the progress of the transfer until the connection is established between caller and callee. If the connection cannot be established (e.g. no answer, line busy, etc.), the session remains active and returns control to the application. As in the case of a blind transfer, if the connection is established, the interpreter disconnects from the session, connection.disconnect.transfer is thrown, and document interpretation continues normally. Any connection between the caller and the callee remains in place regardless of document execution. For additional information on call transfers with consultation-like functionality see [ATT_50075], [MCI_ECR], and [ETSI300_369].

Figure 1: Audio Connections during a consultation transfer: <transfer type="consultation"/>
The VoiceXML implementation platform is not part of the audio connection between the caller and callee after a succesfully established consultation transfer.

The possible outcomes for a consultation transfer before the connection to the callee is established are:

Table 11: Consultation Transfer Outcomes Prior to Connection Being Established
ActionValue of form item variableEventReason
caller disconnects connection.disconnect.hangupThe caller hung up.
caller cancels transfer before outgoing call beginsnear_end_disconnectThe caller cancelled the transfer attempt via a DTMF or voice command before the outgoing call begins (during playback of queued audio).
callee busybusy The callee was busy.
network busynetwork_busy An intermediate network refused the call.
callee does not answernoanswer There was no answer within the time specified by the connecttimeout attribute.
---unknown The transfer ended but the reason is not known.

The possible outcomes for a consultation transfer once the connection to the callee is established are:

Table 12: Consultation Transfer Outcome After Connection Has Been Established
ActionValue of form item variableEventReason
transfer beginsundefinedconnection.disconnect.transferThe caller was transferred to another line and will not return.

9.2 Consultation Transfer Errors and Events

One of the following events may be thrown during a consultation transfer:

Table 13: Events thrown during consultation transfer
EventReason
connection.disconnect.hangupThe caller hung up.
connection.disconnect.transferThe caller was transferred to another line and will not return.

If a consultation transfer could not be made, one of the following errors will be thrown:

Table 14: Consultation transfer attempt error events
ErrorReason
error.connection.noauthorizationThe caller is not allowed to call the destination.
error.connection.baddestination The destination URI is malformed.
error.connection.noroute The platform is not able to place a call to the destination.
error.connection.noresource The platform cannot allocate resources to place the call.
error.connection.protocol.nnnThe protocol stack for this connection raised an exception that does not correspond to one of the other error.connection events.
error.unsupported.transfer.consultationThe platform does not support consultation transfer.
error.unsupported.uri The platform does not support the URI format used. The special variable _message (section 5.2.2 of [VXML2]) will contain the string "The URI x is not a supported URI format" where x is the URI from the dest or destexpr <transfer> attributes.

9.3 Example of a Consultation Transfer

The following example attempts to perform a consultation transfer of the caller to a another party. Prompts may be included before or within the <transfer> element. This may be used to inform the caller of what is happening, with a notice such as "Please wait while we transfer your call." The <prompt> within the <block>, and the <prompt> within <transfer> are queued and played before actually performing the transfer. After the prompt queue is flushed, the outgoing call is initiated. The "transferaudio" attribute specifies an audio file to be played to the caller in place of audio from the far-end until the far-end answers. If the audio source is longer than the connect time, the audio will stop playing immediately upon far-end answer.

Figure 2: Sequence and timing during an example of a consultation transfer
Sequence and timing diagram during a consultation transfer.

<?xml version="1.0" encoding="UTF-8"?>
<vxml version="2.1" 
  xmlns="http://www.w3.org/2001/vxml">
<catch event="connection.disconnect.transfer">
   <!-- far-end answered -->
   <log> Connection with the callee established: transfer executed.</log>
</catch>

<form id="consultation_xfer">
   <block>
     <!-- queued and played before starting the transfer -->
     <prompt>
        Calling Riley.
     </prompt>
   </block>
   <!-- Play music while attempting to connect to far-end -->
   <!-- Wait up to 60 seconds for the far end to answer  -->
   <transfer name="mycall" dest="tel:+1-555-123-4567"
      transferaudio="music.wav" connecttimeout="60s" type="consultation">
     <!-- queued and played before starting the transfer -->
     <prompt>
        Please wait...
     </prompt>
     <filled>
        <if cond="mycall == 'busy'">
           <prompt>
             Riley's line is busy. Please call again later.
           </prompt>
         <elseif cond="mycall == 'noanswer'"/>
           <prompt>
             Riley can't answer the phone now. Please call
             again later.
           </prompt>
         </if>
      </filled>
   </transfer>
   <!-- submit call statistics to server -->
   <block>
      <submit namelist="mycall" next="/cgi-bin/report"/>
   </block>
</form>
</vxml>

A VoiceXML Document Type Definition

The VoiceXML DTD is located at http://www.w3.org/TR/voicexml21/vxml.dtd.

Due to DTD limitations, the VoiceXML DTD does not correctly express that the <metadata> element can contain elements from other XML namespaces.

Note:

The VoiceXML DTD includes modified elements from the DTDs of the Speech Recognition Grammar Specification 1.0 [SRGS] and the Speech Synthesis Markup Language 1.0 [SSML].

B VoiceXML Schema

This section is Normative.

The VoiceXML schema is located at http://www.w3.org/TR/voicexml21/vxml.xsd.

The VoiceXML schema depends upon other schema defined in the VoiceXML namespace:

The complete set of Speech Interface Framework schema required for VoiceXML 2.1 is available here.

Note:

In order to accomodate the addition of the nameexpr attribute, the definition of the <mark> element has been modified in synthesis-core.xsd: the name attribute is now optional.

C Conformance

This section is normative.

C.1 Conforming VoiceXML 2.1 Document

A conforming VoiceXML 2.1 document is a well-formed [XML] document that requires only the facilities described as mandatory in this specification and in [VXML2]. Such a document must meet all of the following criteria:

  1. The document must conform to the constraints expressed in the VoiceXML 2.1 Schema
  2. The root element of the document must be <vxml>.
  3. The <vxml> element must include a "version" attribute with the value "2.1".
  4. The <vxml> element must designate the VoiceXML namespace using the "xmlns" attribute [XMLNAMES]. The namespace for VoiceXML is defined to be http://www.w3.org/2001/vxml.
  5. It is recommended that the <vxml> element also include "xmlns:xsi" and "xsi:schemaLocation" attributes to indicate the location of the schema for the VoiceXML namespace. If the "xsi:schemaLocation" attribute is present, it must include a reference to the VoiceXML 2.1 Schema:
    xsi:schemaLocation="http://www.w3.org/2001/vxml 
      http://www.w3.org/TR/voicexml21/vxml.xsd"
  6. There may be a DOCTYPE declaration in the document prior to the root element. If present, the public identifier included in the DOCTYPE declaration must reference the VoiceXML 2.1 DTD using its Formal Public Identifier.
    <!DOCTYPE vxml 
      PUBLIC "-//W3C//DTD VOICEXML 2.1//EN" 
      "http://www.w3.org/TR/voicexml21/vxml.dtd">
    The system identifier may be modified appropriately. The DTD subset must not be used to override any parameter entities in the DTD.

Here is an example of a Conforming VoiceXML 2.1 document:

<?xml version="1.0" encoding="UTF-8"?>
<vxml version="2.1" xmlns="http://www.w3.org/2001/vxml"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xsi:schemaLocation="http://www.w3.org/2001/vxml 
  http://www.w3.org/TR/voicexml21/vxml.xsd">

  <form>
    <block>hello</block>
  </form>

</vxml>

Note that in this example, the recommended "xmlns:xsi" and "xsi:schemaLocation" attributes are included as is an XML declaration. An XML declaration like the one above is not required in all XML documents. VoiceXML document authors are strongly encouraged to use XML declarations in all their documents. Such a declaration is required when the character encoding of the document is other than the default UTF-8 or UTF-16 and no encoding was determined by a higher-level protocol.

The VoiceXML language or these conformance criteria provide no designated size limits on any aspect of VoiceXML 2.1 documents. There are no maximum values on the number of elements, the amount of character data, or the number of characters in attribute values.

C.2 Using VoiceXML with other namespaces

The VoiceXML namespace may be used with other XML namespaces as per [XMLNAMES], although such documents are not strictly conforming VoiceXML 2.1 documents as defined above. Future work by W3C will address ways to specify conformance for documents involving multiple namespaces.

C.3 Conforming VoiceXML 2.1 Processors

A VoiceXML 2.1 processor is a user agent that can parse and process Conforming VoiceXML 2.1 documents.

In a Conforming VoiceXML 2.1 Processor, the XML parser must be able to parse and process all well-formed XML constructs defined within [XML] and [XMLNAMES]. It is not required that a Conforming VoiceXML 2.1 processor use a validating parser.

A Conforming VoiceXML 2.1 Processor must be a Conforming Speech Synthesis Markup Language Processor [SSML] and a Conforming XML Grammar Processor [SRGS] except for differences described in this document. If a syntax error is detected while processing a grammar document, then an "error.badfetch" event must be thrown.

A Conforming VoiceXML 2.1 Processor must support the syntax and semantics of all VoiceXML elements as described in this document and in [VXML2]. Consequently, a Conforming VoiceXML 2.1 Processor must not throw an 'error.unsupported.<element>' for any VoiceXML element which must be supported when processing a Conforming VoiceXML 2.1 Document.

When a Conforming VoiceXML 2.1 Processor encounters a Conforming VoiceXML 2.1 Document with non-VoiceXML elements or attributes which are proprietary, defined only in versions of VoiceXML earlier than [VXML2], or defined in a non-VoiceXML namespace, and which cannot be processed, then it must throw an "error.badfetch" event.

When a Conforming VoiceXML 2.1 Processor encounters a document with a root element designating a namespace other than VoiceXML, its behavior is undefined.

When a Conforming VoiceXML 2.1 Processor encounters a non-Conforming VoiceXML 2.0 or 2.1 document, its behavior is undefined.

There is, however, no conformance requirement with respect to performance characteristics of the VoiceXML 2.1 Processor.

While the features of VoiceXML 2.1 are orthogonal additions to [VXML2], a VoiceXML application should not mix documents of both types. The handling of a single application that mixes VoiceXML 2.0 and VoiceXML 2.1 functionality is platform-specific. Reasonable behavior in this case ranges the gamut from successful execution to the throwing of an error.

Interpreters that support both VoiceXML 2.0 and VoiceXML 2.1 must support the ability to transition from an application of one version to an application of another version.

Note:

The xsd:anyURI type and thus URI references in VoiceXML documents may contain a wide array of international characters. Implementers should reference [RFC 3987] and the [CHARMODEL] in order to provide appropriate support for these characters in VoiceXML documents and when processing values of this type or mapping them to URIs.

D ECMAScript Language Binding for DOM

This appendix contains the ECMAScript binding for the subset of Level 2 of the Document Object Model exposed by the <data> element.

Prototype Object DOMException
The DOMException class has the following constants:
DOMException.INDEX_SIZE_ERR
This constant is of type Number and its value is 1.
DOMException.DOMSTRING_SIZE_ERR
This constant is of type Number and its value is 2.
DOMException.HIERARCHY_REQUEST_ERR
This constant is of type Number and its value is 3.
DOMException.WRONG_DOCUMENT_ERR
This constant is of type Number and its value is 4.
DOMException.INVALID_CHARACTER_ERR
This constant is of type Number and its value is 5.
DOMException.NO_DATA_ALLOWED_ERR
This constant is of type Number and its value is 6.
DOMException.NO_MODIFICATION_ALLOWED_ERR
This constant is of type Number and its value is 7.
DOMException.NOT_FOUND_ERR
This constant is of type Number and its value is 8.
DOMException.NOT_SUPPORTED_ERR
This constant is of type Number and its value is 9.
DOMException.INUSE_ATTRIBUTE_ERR
This constant is of type Number and its value is 10.
DOMException.INVALID_STATE_ERR
This constant is of type Number and its value is 11.
DOMException.SYNTAX_ERR
This constant is of type Number and its value is 12.
DOMException.INVALID_MODIFICATION_ERR
This constant is of type Number and its value is 13.
DOMException.NAMESPACE_ERR
This constant is of type Number and its value is 14.
DOMException.INVALID_ACCESS_ERR
This constant is of type Number and its value is 15.
The DOMException object has the following properties:
code
This property is of type Number.

Object DOMImplementation
The object has the following methods:
hasFeature(feature, version)
This method returns a Boolean.
The feature parameter is of type String .
The version parameter is of type String .
createDocumentType(qualifiedName, publicId, systemId)
This method returns a DocumentType object.
The qualifiedName parameter is of type String .
The publicId parameter is of type String .
The systemId parameter is of type String .
This method can raise a DOMException object.
createDocument(namespaceURI, qualifiedName, doctype)
This method returns a Document object.
The namespaceURI parameter is of type String .
The qualifiedName parameter is of type String .
The doctype parameter is a DocumentType object .
This method can raise a DOMException object.

Object DocumentFragment
DocumentFragment has all the properties and methods of the Node object .

Object Document
Document has all the properties and methods of the Node object as well as the properties and methods defined below.
The Document object has the following properties:
doctype
This read-only property is a DocumentType object.
implementation
This read-only property is a DOMImplementation object.
documentElement
This read-only property is a Element object.
The object has the following methods:
createElement(tagName)
This method returns a Element object.
The tagName parameter is of type String .
This method can raise a DOMException object.
createDocumentFragment()
This method returns a DocumentFragment object.
This method can raise a DOMException object.
createTextNode(data)
This method returns a Text object.
The data parameter is of type String .
createComment(data)
This method returns a Comment object.
The data parameter is of type String .
createCDATASection(data)
This method returns a CDATASection object.
The data parameter is of type String .
This method can raise a DOMException object.
createProcessingInstruction(target, data)
This method returns a ProcessingInstruction object.
The target parameter is of type String .
The data parameter is of type String .
This method can raise a DOMException object.
createAttribute(name)
This method returns a Attr object.
The name parameter is of type String .
This method can raise a DOMException object.
createEntityReference(name)
This method returns a EntityReference object.
The name parameter is of type String .
This method can raise a DOMException object.
getElementsByTagName(tagname)
This method returns a NodeList object.
The tagname parameter is of type String .
importNode(importedNode, deep)
This method returns a Node object.
The importedNode parameter is a Node object .
The deep parameter is of type Boolean .
This method can raise a DOMException object.
createElementNS(namespaceURI, qualifiedName)
This method returns a Element object.
The namespaceURI parameter is of type String .
The qualifiedName parameter is of type String .
This method can raise a DOMException object.
createAttributeNS(namespaceURI, qualifiedName)
This method returns a Attr object.
The namespaceURI parameter is of type String .
The qualifiedName parameter is of type String .
This method can raise a DOMException object.
getElementsByTagNameNS(namespaceURI, localName)
This method returns a NodeList object.
The namespaceURI parameter is of type String .
The localName parameter is of type String .
getElementById(elementId)
This method returns a Element object.
The elementId parameter is of type String .

Prototype Object Node
The Node class has the following constants:
Node.ELEMENT_NODE
This constant is of type Number and its value is 1.
Node.ATTRIBUTE_NODE
This constant is of type Number and its value is 2.
Node.TEXT_NODE
This constant is of type Number and its value is 3.
Node.CDATA_SECTION_NODE
This constant is of type Number and its value is 4.
Node.ENTITY_REFERENCE_NODE
This constant is of type Number and its value is 5.
Node.ENTITY_NODE
This constant is of type Number and its value is 6.
Node.PROCESSING_INSTRUCTION_NODE
This constant is of type Number and its value is 7.
Node.COMMENT_NODE
This constant is of type Number and its value is 8.
Node.DOCUMENT_NODE
This constant is of type Number and its value is 9.
Node.DOCUMENT_TYPE_NODE
This constant is of type Number and its value is 10.
Node.DOCUMENT_FRAGMENT_NODE
This constant is of type Number and its value is 11.
Node.NOTATION_NODE
This constant is of type Number and its value is 12.
The Node object has the following properties:
nodeName
This read-only property is of type String.
nodeValue
This property is of type String. This property can raise a DOMException object on retrieval.
nodeType
This read-only property is of type Number.
parentNode
This read-only property is a Node object.
childNodes
This read-only property is a NodeList object.
firstChild
This read-only property is a Node object.
lastChild
This read-only property is a Node object.
previousSibling
This read-only property is a Node object.
nextSibling
This read-only property is a Node object.
attributes
This read-only property is a NamedNodeMap object.
ownerDocument
This read-only property is a Document object.
namespaceURI
This read-only property is of type String.
prefix
This property is of type String.
localName
This read-only property is of type String.
The object has the following methods:
insertBefore(newChild, refChild)
This method returns a Node object.
The newChild parameter is a Node object .
The refChild parameter is a Node object .
This method can raise a DOMException object.
replaceChild(newChild, oldChild)
This method returns a Node object.
The newChild parameter is a Node object .
The oldChild parameter is a Node object .
This method can raise a DOMException object.
removeChild(oldChild)
This method returns a Node object.
The oldChild parameter is a Node object .
This method can raise a DOMException object.
appendChild(newChild)
This method returns a Node object.
The newChild parameter is a Node object .
This method can raise a DOMException object.
hasChildNodes()
This method returns a Boolean.
cloneNode(deep)
This method returns a Node object.
The deep parameter is of type Boolean .
normalize()
This method has no return value.
isSupported(feature, version)
This method returns a Boolean.
The feature parameter is of type String .
The version parameter is of type String .
hasAttributes()
This method returns a Boolean.

Object NodeList
The NodeList object has the following properties:
length
This read-only property is of type Number.
The object has the following methods:
item(index)
This method returns a Node object.
The index parameter is of type Number .

Object NamedNodeMap
The NamedNodeMap object has the following properties:
length
This read-only property is of type Number.
The object has the following methods:
getNamedItem(name)
This method returns a Node object.
The name parameter is of type String .
setNamedItem(arg)
This method returns a Node object.
The arg parameter is a Node object .
This method can raise a DOMException object.
removeNamedItem(name)
This method returns a Node object.
The name parameter is of type String .
This method can raise a DOMException object.
item(index)
This method returns a Node object.
The index parameter is of type Number .
getNamedItemNS(namespaceURI, localName)
This method returns a Node object.
The namespaceURI parameter is of type String .
The localName parameter is of type String .
setNamedItemNS(arg)
This method returns a Node object.
The arg parameter is a Node object .
This method can raise a DOMException object.
removeNamedItemNS(namespaceURI, localName)
This method returns a Node object.
The namespaceURI parameter is of type String .
The localName parameter is of type String .
This method can raise a DOMException object.

Object CharacterData
CharacterData has all the properties and methods of the Node object as well as the properties and methods defined below.
The CharacterData object has the following properties:
data
This property is of type String. This property can raise a DOMException object on retrieval.
length
This read-only property is of type Number.
The object has the following methods:
substringData(offset, count)
This method returns a String.
The offset parameter is of type Number .
The count parameter is of type Number .
This method can raise a DOMException object.
appendData(arg)
This method has no return value.
The arg parameter is of type String .
This method can raise a DOMException object.
insertData(offset, arg)
This method has no return value.
The offset parameter is of type Number .
The arg parameter is of type String .
This method can raise a DOMException object.
deleteData(offset, count)
This method has no return value.
The offset parameter is of type Number .
The count parameter is of type Number .
This method can raise a DOMException object.
replaceData(offset, count, arg)
This method has no return value.
The offset parameter is of type Number .
The count parameter is of type Number .
The arg parameter is of type String .
This method can raise a DOMException object.

Object Attr
Attr has all the properties and methods of the Node object as well as the properties and methods defined below.
The Attr object has the following properties:
name
This read-only property is of type String.
specified
This read-only property is of type Boolean.
value
This property is of type String.
ownerElement
This read-only property is a Element object.

Object Element
Element has all the properties and methods of the Node object as well as the properties and methods defined below.
The Element object has the following properties:
tagName
This read-only property is of type String.
The object has the following methods:
getAttribute(name)
This method returns a String.
The name parameter is of type String .
setAttribute(name, value)
This method has no return value.
The name parameter is of type String .
The value parameter is of type String .
This method can raise a DOMException object.
removeAttribute(name)
This method has no return value.
The name parameter is of type String .
This method can raise a DOMException object.
getAttributeNode(name)
This method returns a Attr object.
The name parameter is of type String .
setAttributeNode(newAttr)
This method returns a Attr object.
The newAttr parameter is a Attr object .
This method can raise a DOMException object.
removeAttributeNode(oldAttr)
This method returns a Attr object.
The oldAttr parameter is a Attr object .
This method can raise a DOMException object.
getElementsByTagName(name)
This method returns a NodeList object.
The name parameter is of type String .
getAttributeNS(namespaceURI, localName)
This method returns a String.
The namespaceURI parameter is of type String .
The localName parameter is of type String .
setAttributeNS(namespaceURI, qualifiedName, value)
This method has no return value.
The namespaceURI parameter is of type String .
The qualifiedName parameter is of type String .
The value parameter is of type String .
This method can raise a DOMException object.
removeAttributeNS(namespaceURI, localName)
This method has no return value.
The namespaceURI parameter is of type String .
The localName parameter is of type String .
This method can raise a DOMException object.
getAttributeNodeNS(namespaceURI, localName)
This method returns a Attr object.
The namespaceURI parameter is of type String .
The localName parameter is of type String .
setAttributeNodeNS(newAttr)
This method returns a Attr object.
The newAttr parameter is a Attr object .
This method can raise a DOMException object.
getElementsByTagNameNS(namespaceURI, localName)
This method returns a NodeList object.
The namespaceURI parameter is of type String .
The localName parameter is of type String .
hasAttribute(name)
This method returns a Boolean.
The name parameter is of type String .
hasAttributeNS(namespaceURI, localName)
This method returns a Boolean.
The namespaceURI parameter is of type String .
The localName parameter is of type String .

Object Text
Text has all the properties and methods of the CharacterData object .

Object Comment
Comment has all the properties and methods of the CharacterData object .

Object CDATASection
CDATASection has all the properties and methods of the Text object .

Object DocumentType
DocumentType has all the properties and methods of the Node object as well as the properties and methods defined below.
The DocumentType object has the following properties:
name
This read-only property is of type String.
entities
This read-only property is a NamedNodeMap object.
notations
This read-only property is a NamedNodeMap object.
publicId
This read-only property is of type String.
systemId
This read-only property is of type String.
internalSubset
This read-only property is of type String.

Object Notation
Notation has all the properties and methods of the Node object as well as the properties and methods defined below.
The Notation object has the following properties:
publicId
This read-only property is of type String.
systemId
This read-only property is of type String.

Object Entity
Entity has all the properties and methods of the Node object as well as the properties and methods defined below.
The Entity object has the following properties:
publicId
This read-only property is of type String.
systemId
This read-only property is of type String.
notationName
This read-only property is of type String.

Object EntityReference
EntityReference has all the properties and methods of the Node object .

Object ProcessingInstruction
ProcessingInstruction has all the properties and methods of the Node object as well as the properties and methods defined below.
The ProcessingInstruction object has the following properties:
target
This read-only property is of type String.
data
This property is of type String.

E References

E.1 Normative References

DOM2
DOM Level 2, ed. Arnaud Le Hors et al. W3C Recommendation, November 2000. See http://www.w3.org/TR/DOM-Level-2-Core/.
SRGS
Speech Recognition Grammar Specification Version 1.0, ed. Andrew Hunt and Scott McGlashan W3C Recommendation, March 2004. See http://www.w3.org/TR/2004/REC-speech-grammar-20040316/.
SSML
Speech Synthesis Markup Language, ed. Daniel C. Burnett et al. W3C Working Draft, December 2002. See http://www.w3.org/TR/2003/CR-speech-synthesis-20031218/.
RFC2119
Key words for use in RFCs to Indicate Requirement Levels, ed. S. Bradner, March 1997. See http://www.ietf.org/rfc/rfc2119.txt.
RFC2616
Hypertext Transfer Protocol -- HTTP/1.1, ed. R. Fielding et al. IETF RFC 2616, June 1999. See http://www.ietf.org/rfc/rfc2616.txt.
VXML2
VoiceXML 2.0, ed. Scott McGlashan et al. W3C Recommendation, March 2004. See http://www.w3.org/TR/2004/REC-voicexml20-20040316/.
XML
Extensible Markup Language (XML) 1.0, ed. Tim Bray et al. W3C Recommendation, February 2004. See http://www.w3.org/TR/2004/REC-xml-20040204/.
XMLNAMES
Namespaces in XML, ed. Tim Bray et al. W3C Recommendation, January 1999. See http://www.w3.org/TR/1999/REC-xml-names-19990114/.

E.3 Acknowledgements

VoiceXML 2.1 was written by the participants in the W3C Voice Browser Working Group. The following have significantly contributed to writing this specification:

  • Matt Oshry, Tellme Networks
  • RJ Auburn, Voxeo Corporation
  • Paolo Baggia, Loquendo
  • Michael Bodell, Tellme Networks
  • David Burke, Voxpilot Ltd.
  • Daniel C. Burnett, Invited Expert
  • Emily Candell, Comverse
  • Ken Davies, HeyAnita
  • Jim Ferrans, Motorola
  • Jeff Haynie, Vocalocity
  • Matt Henry, Voxeo Corporation
  • Hakan Kilic, Scansoft
  • Scott McGlashan, Hewlett-Packard
  • Brien Muschett, IBM
  • Rob Marchand, VoiceGenie
  • Jeff Kusnitz, IBM
  • Brad Porter, Tellme Networks
  • Ken Rehor, Vocalocity
  • Laura Ricotti, Loquendo
  • Davide Tosello, Loquendo
  • Milan Young, Nuance

F Summary of changes since the Last Call Working Draft

The following is a summary of the major changes since the Last Call Working Draft was published.