Ruby loop

[Abhamid (Hamid ABOU)]

Dear,
I am a new one in ELK suite, i want use logstash, to update some fields in xml file before insert them in elastcis.
My problem is that the xml file, has a nested fields, and from file tof ile, the numebr of netsed field is not same.

 **here after an xml file**

 <?xml version="1.0"?>
      -<test1 xmlns="test1s.model.toto.com">
               <Version>V01.13</Version>
               <T_ID>370501</T_ID>
               <Stt>5</Stt>
               <S_ID2>3705</S_ID2>
               <Date>2016-12-13T10:04:54.697Z</Date>
               -<Opes>
                      -<Ope Type="1">
                              <Start>2016-12-13T10:04:55.570Z</Start>
                             <End>2016-12-13T10:04:56.120Z</End>
                             <S_ID2>3705</S_ID2>
                             <Vrdt Value="2">2</Vrdt>
                      </Ope>
                     -<Ope Type="3">
                             <Start>2016-12-13T10:05:36.883Z</Start>
                             <End>2016-12-13T10:05:44.287Z</End>
                             <Log_tst>scv</Log_tst>
                             <Wk_test>toto_tst</Wk_test>
                             <S_ID2>3705</S_ID2>
                             <Vrdt Value="0">0</Vrdt>
                       </Ope>
                </Opes>
                <UpdateDateTime>2016-12-13T10:05:45.030Z</UpdateDateTime>
                <LastStateDateTime>2016-12-13T10:05:45.027Z</LastStateDateTime>
    </test1>

here a logstash pipeline file

input {
file {
path => "/usr/share/img_pro/**/*.xml"
type => "data_xml"
codec => plain {
charset => "ISO-8859-1"
}
start_position => "beginning"
sincedb_path => "/dev/null"
}
}
filter {
if [type] == "data_xml" {

      xml {
            source => "message"
            store_xml => true
            target => "parsed_xml"
		}
   }

ruby {
code => "
event['[parsed_xml][Opes[0]][Ope]'].each {|Op| event ['[Op][Vrdt[0]][Value]'] = "Val1" }
"
}
}

mutate {
remove_field => ["message", "host", "port", "tags", "@version", "@timestamp"]
}

}
output {
if "_xmlparsefailure" not in [tags]
{
stdout { codec => rubydebug }
}else {
file {
path => "/usr/share/bad_xml/xml-bad.tsv"
}
}
}

What i want is to update field " Vrdt" to "test_0" if it's value is 0, to to "test_1" if it's value is 1, ... for exemple.

Thank you for your help