gistfile1.txt

class file_filler {
        define filled_file($content='') {
                file { $name: }
                case $content {
        	  '': { File[$name] { content => "I was filled\n" } }
        	  default: { File[$name] { content => $content } 
                }
	}      
        filled_file { ["/tmp/a", "/tmp/b"]: }
}

class test {
        include file_filler
}

include test