Validator

Definition

<validator name="ValidatorName">

Checks the validity of some predicate in an http_service or a device module.

Attribute	Type	Description
name	string	Required. The name of the validator class. Names are written according to the PascalCase convention, e.g. 'CityRecognizer'.

Children

• <parameters>
  • <parameter>
• <target>
  • <http>
  • <device_module>

Behaviour

The <validator> element in the service interface checks the validity of a parameter using the specified module in <target>. The target service must be either an http_service or a device module, which would return either true or false as the value for "is_valid" inside a validator response.

If the target module returns a "is_valid": false, that will trigger the system to reject the user utterance, and explain to the user why the parameter was rejected. The rejecting utterance will need to be defined in the grammar.

Examples

Check in an http_service if the value and grammar entry for the destination city are valid

  <validator name="CityValidity">
    <parameters>
      <parameter predicate="dest_city" format="value"/>
      <parameter predicate="dest_city" format="grammar_entry"/>
    </parameters>
    <target>
      <http endpoint="http://127.0.0.1:10100/city_validity"/>
    </target>
  </validator>