<?xml version="1.0" encoding="UTF-8"?>
<vxml version="2.0" xmlns="http://www.w3.org/2001/vxml">

<meta name="description" content="mixed initiative dialog, filled and counters example"/>
<meta name="author" content="OptimSys, s.r.o., Czech Republic (http://www.optimsys.cz)"/>
<meta name="copyright" content="free for any purpose"/>

<link event="again">
  <grammar root="main">
    <rule id="main" scope="public">
      <item repeat="0-1"> please </item>
      <item repeat="0-1"> all </item>
      <one-of>
        <item> again </item>
        <item> once more </item>
      </one-of>
      <item repeat="0-1"> please </item>
    </rule>
  </grammar>
</link>

<nomatch>
  Sorry, I did not understand you.
  <reprompt/>
</nomatch>

<form id="get_from_and_to_cities">
  <grammar src="cities.grxml"/>

  <catch event="again">
    <prompt> OK, once more!</prompt>
    <clear namelist="bypass_init from_city to_city"/>
    <reprompt/>
  </catch>

  <nomatch count="2">
    I am sorry, I still do not understand you. Valid cities are London, Prague and Rome
  </nomatch>
  <nomatch count="3">
    I did not understand again. I am giving up. Bye.
    <exit/>
  </nomatch>

  <block> Welcome to the airplain ticket reservation system. </block>

  <initial name="bypass_init">
    Where do you want to fly from and to?
    <nomatch count="1">
      Sorry, I did not understand you. Say something like "from London to Prague".
    </nomatch>
    <nomatch count="2">
      I am sorry, I still don't understand.
      I will ask you for information one piece at a time.
      <assign name="bypass_init" expr="true"/>
      <reprompt/>
    </nomatch>
  </initial>

  <field name="from_city" slot="from">
    <grammar src="cities.grxml#from"/>
    From which city are you leaving?
    <prompt count="2"> Tell me from which city you are leaving, please </prompt>
  </field>

  <field name="to_city" slot="to">
    <grammar src="cities.grxml#to"/>
    To which city do you want to fly?
    <prompt count="2"> Tell me to which city you want to fly, please </prompt>
  </field>

  <block>
    <prompt>
      A ticket from <value expr="from_city"/> to <value expr="to_city"/>
      is reserved for you.
    </prompt>
  </block>

  <filled namelist="from_city">
    <prompt>Your departure city is <value expr="from_city"/>.</prompt>
  </filled>

  <filled namelist="to_city">
    <prompt>Your arrival city is <value expr="to_city"/>.</prompt>
  </filled>

  <filled>
    <if cond="from_city==to_city">
      <prompt>
        Sorry, you can't fly from <value expr="from_city"/> to <value expr="to_city"/>!
      </prompt>
      <prompt>
        Please repeat your order.
      </prompt>
      <clear namelist="bypass_init from_city to_city"/>
    </if>
  </filled>

</form>

</vxml>

<?xml version="1.0" encoding="UTF-8"?>
<grammar root="main" version="1.0" xml:lang="en">

  <meta name="description" content="from/to city grammar"/>
  <meta name="author" content="OptimSys, s.r.o., Czech Republic (http://www.optimsys.cz)"/>
  <meta name="copyright" content="free for any purpose"/>

  <rule id="main" scope="public">
    <item repeat="0-1">
      <ruleref uri="#filler"/>
    </item>
    <one-of>
      <item>
        from
        <ruleref uri="#city"/> <tag> out.from = rules.city; </tag>
        to
        <ruleref uri="#city"/> <tag> out.to = rules.city; </tag>
      </item>
      <item>
        from
        <ruleref uri="#city"/> <tag> out.from = rules.city; </tag>
      </item>
      <item>
        to
        <ruleref uri="#city"/> <tag> out.to = rules.city; </tag>
      </item>
    </one-of>
  </rule>

  <rule id="from" scope="public">
    <item repeat="0-1">
      <ruleref uri="#filler"/>
    </item>
    <item repeat="0-1">
      from
    </item>
    <ruleref uri="#city"/> <tag> out.from = rules.city; </tag>
  </rule>

  <rule id="to" scope="public">
    <item repeat="0-1">
      <ruleref uri="#filler"/>
    </item>
    <item repeat="0-1">
      to
    </item>
    <ruleref uri="#city"/> <tag> out.to = rules.city; </tag>
  </rule>

  <rule id="filler">
    I want
    <item repeat="0-1">
      to fly
    </item>
  </rule>

  <rule id="city">
    <one-of>
      <item> London </item>
      <item> Prague </item>
      <item> Rome </item>
    </one-of>
  </rule>
</grammar>