Apply defaults to command object based on configuration service

How can I apply defaults to a command object in Grails 2.3?

Note that I need to retrieve these defaults from a service when the corresponding url param is unspecified.

I have the following command object as the argument to my action

class SearchCommand {

    int page
    int pageSize     // todo: get default from configurationService

    String orderBy   // todo: get default from configurationService
    String search

}

I've looked at @BindUsing but it doesn't seem to be invoked when the corresponding request parameter is missing, defeating my attempt at applying a default value.

You could also do something like this:

A controller..

// grails-app/controllers/com/demo/DemoController.groovy

package com.demo

class DemoController {

    def createPerson(Person p) {
        render "First Name: ${p.firstName}, Last Name: ${p.lastName}"
    }
}

class Person {
    String firstName
    String lastName
}

A service...

// grails-app/services/com/demo/MyConfigurationService.groovy

package com.demo

class MyConfigurationService {

    def initializePerson(Person p) {
        p.firstName = 'Default First Name'
        p.lastName = 'Default Last Name'
    }
}

A binding listener...

// src/groovy/com/demo/PersonBindingListener.groovy
package com.demo

import org.grails.databinding.events.DataBindingListenerAdapter

class PersonBindingListener extends DataBindingListenerAdapter {

    def configService

    Boolean beforeBinding(Object target, Object errors) {
        configService.initializePerson target
        true
    }


    boolean supports(Class<?> clazz) {
        clazz == Person
    }
}

Register the listener bean...

// grails-app/conf/spring/resources.groovy

beans = {
    myListener(com.demo.PersonBindingListener) {
        configService = ref('myConfigurationService')
    }
}