Grails URL mapping Based on dynamic request properties

grails_dynamic_url_mappings.groovy

"/path/to/stuff"(controller:"controller", action: "action"){
  param={
    def rtn = "get"
    switch(request.method) {
    case "GET":
      rtn = "get"
      break
    case "PUT":
      rtn = "update"
      break
    }
    return rtn
  }
  format = "html"
}