How can I register a custom json deserializer/parser in Grails?

Question

Should I use filters or interceptors to meet the requirements, isn't there a simpler way?

UPDATE:
Looks like that my old code worked just fine, I've inadvertently edited the resources.groovy and invalidated the bean definition

resources.groovy
================

beans = {
    dateConverter DateConverter
}

BootStrap.groovy
================

class BootStrap {
    def grailsApplication

    def init = { servletContext ->
       def ctx = grailsApplication.mainContext
       def dataBinder = ctx.getBean(org.grails.databinding.SimpleDataBinder)
       dataBinder.conversionHelpers[Date] = [ctx.getBean('dateConverter')]
    }
 }

Answer 1

If you want to change it globally you can do something like this:

    class Foo {
        String name
    }

and in Bootstrap.groovy (or whatever place you prefer):

    JSON.registerObjectMarshaller(Foo) {
        [name:it.name()]
    }

If you need it only in special cases the easiest (in my experience) is to create a map and convert it to JSON

[name:'foo'] as JSON

Update

@BindUsingdoes work for command objects too..

class FooController {
    def foo (FooCmd bind) {
       render (text: "${bind.foo}")
    }
}

class FooCmd {
    @BindUsing({ obj, src ->
        "@BindUsing ${src['foo']}"
    })
    String foo
}

curl -i -H "Content-Type: application/json" -d '{"foo":"FOO!!!!"}' http://localhost:8080/Stackoverflow/Foo/foo