groovy_collection_to_xml

import groovy.xml.*

def collection = [
  [ key:'tim',  value:null ],
  [ key:'brenda', value:32 ]
]

def process = { binding, element ->
     binding."${element.key}"( element.value )
}

println XmlUtil.serialize( new StreamingMarkupBuilder().with { builder ->
  builder.bind { binding ->
    data {
          collection.each { e ->
          process( binding, e )
        }
    }
  }
})