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[VXML 2.0] Doubt regarding <clear> namelist token

From: Rajesh N <rajeshn@huawei.com>
Date: Thu, 07 May 2009 19:31:05 +0530
To: www-voice@w3.org
Message-id: <015201c9cf1c$43dd99c0$2001120a@china.huawei.com>
Hi,

 

I have a doubt regarding the resolution of a variable name present in the
namelist attribute of <clear>.

 

Consider the VXML script given below.

 

        <?xml version="1.0"?>

        <vxml version="2.0" xmlns="http://www.w3.org/2001/vxml">

          <form>

            <field name="pin" type="digits?length=4">

              <prompt>Enter your 4 digit pin number?</prompt>

              <filled>

                <if cond="pin == 9090">

                    Great! You entered the correct pin number

                <else/>

                    Sorry, Invalid pin - please try again

                    <clear namelist="pin"/>

                </if>                    

              </filled>

            </field>

          </form>

        </vxml>

 

Here, if the user input is not 9090, then the <else> part is executed. In
<clear>, the variable name "pin" corresponds to a form-item name (the
current one itself). Hence the <field>'s input item variable gets reset to
undefined and its prompt counter and event counters get reset (thereby
making it eligible for selection in next FIA cycle)

 

Consider the following script with a small modification (A local variable
named pin is defined in the anonymous scope of <filled>)

 

        <?xml version="1.0"?>

        <vxml version="2.0" xmlns="http://www.w3.org/2001/vxml">

          <form>

            <field name="pin" type="digits?length=4">

              <prompt>Enter your 4 digit pin number?</prompt>

              <filled>

                <if cond="pin == 9090">

                    Great! You entered the correct pin number

                <else/>

                   <var name="pin" expr="'My local pin number'" />

                    Sorry, Invalid pin - please try again

                    <clear namelist="pin"/>

                </if>                    

              </filled>

            </field>

          </form>

        </vxml>

 

During interpretation of this script, if user input is not 9090, then the
<else> part is executed. Here <var> declares a new local variable named pin.
Now while processing <clear namelist="pin">, which variable should get reset
- Is it the local variable or the form-item variable?

 

VXML 2.0 specification says, for <clear>, for each specified variable name,
the variable is resolved relative to the current scope according to Section
5.1.3 (to remove ambiguity, each variable name in the namelist may be
prefixed with a scope name)

 

So I think, in the second script, the local variable pin should get reset.
If I need the form-item variable to be reset, I should specify "dialog.pin"
in the namelist.

 

Please clarify whether my understanding is correct.

 

Thanks

Rajesh

 
Received on Thursday, 7 May 2009 14:04:30 GMT

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