Dynamically add path in Groovy - grails

Question

I'm trying to add new functionality, without refactoring the entire code. Actually the code calls msg.typeOfMsg('msg'), but I want to add validation when it comes true change all the typeOfMsg to a specific type:
def specialRule = true
def message = changeMessageType()
def changeMessageType() {
def toInform = { def message -> thePath.toChange.inform(message) }
return specialRule ? [reprove : toInform, approve : toInform] : thePath.toChange
}
println(message.reprove('Standart reprove message')
This is the solution I found, it works, but I have a lot of message types and custom message types, there's some way to dynamically change all calls to inform, without refactoring all the code to calls something like message(typeOfMessage, message)?
-----Edit-----
Here's a runnable version
def message = changeMessageType()
def changeMessageType() {
def originalPath = new OriginalPath()
def specialRule = true
def toInform = { def message -> originalPath.inform(message) }
return specialRule ? [reprove : toInform, approve : toInform] : originalPath
}
message.approve('Standart reprove message')
class OriginalPath {
def reprove(message) {
println "Reprove: ${message}"
}
def approve(message) {
println "Approve: ${message}"
}
def inform(message) {
println "Inform: ${message}"
}
}