Templating discovery message in Ruby

In order to template  the discovery message in ruby we manipulate the template string using XML.
The following code convert the template from string to XML , manipulate the service name and name space and convert it back to string representation .

require 'rexml/document'

def TempalteProbeMsg (pMsg)
    doc = REXML::Document.new(pMsg)
   
    theElment = doc.root.elements['s:Body/Probe/d:Types']
   
    theElment.text = 'dp0:IMyServiceToProbe'
   
    theElment.attributes["xmlns:dp0"] ="Com.myCompany.Services"
   
    return   doc.root.to_s
   
end

The probe message before templating

envelope" xmlns:a="http://www.w3.org/2005/08/addressing">
  <s:Header>
    <a:Action s:mustUnderstand="1">http://docs.oasis-open.org/ws-dd/ns/discovery/2009/01/Hello</a:Action>
    <h:AppSequence InstanceId="1369239226" MessageNumber="1" xmlns:h="http://docs.oasis-open.org/ws-dd/ns/discovery/2009/01"/>
    <a:MessageID>urn:uuid:bc95d269-a20f-4d7b-b5bd-c31698dd9569</a:MessageID>
    <a:To s:mustUnderstand="1">urn:docs-oasis-open-org:ws-dd:ns:discovery:2009:01</a:To>
  </s:Header>
  <s:Body>
    <Hello xmlns="http://docs.oasis-open.org/ws-dd/ns/discovery/2009/01">
      <a:EndpointReference>
        <a:Address>http://localhost:8989/myService</a:Address>
      </a:EndpointReference>
      <d:Types xmlns:d="http://docs.oasis-open.org/ws-dd/ns/discovery/2009/01" xmlns:dp0="Com.myCompany.Services">dp0:IMyServiceAlias</d:Types>
      <XAddrs>http://localhost:8989/myService</XAddrs>
      <MetadataVersion>0</MetadataVersion>
    </Hello>
  </s:Body>
</s:Envelope>

The probe message after templating

<s:Envelope xmlns:a='http://www.w3.org/2005/08/addressing' xmlns:s='http://www.w
3.org/2003/05/soap-envelope'>
    <s:Header>
      <a:Action s:mustUnderstand='1'>http://docs.oasis-open.org/ws-dd/ns/discove
ry/2009/01/Probe</a:Action>
      <a:MessageID>urn:uuid:4faf9212-2449-43bd-9cfb-9cf8b12300d1</a:MessageID>
      <a:ReplyTo>
        <a:Address>http://www.w3.org/2005/08/addressing/anonymous</a:Address>
      </a:ReplyTo>
      <a:To s:mustUnderstand='1'>urn:docs-oasis-open-org:ws-dd:ns:discovery:2009
:01</a:To>
    </s:Header>
    <s:Body>
      <Probe xmlns='http://docs.oasis-open.org/ws-dd/ns/discovery/2009/01'>
        <d:Types xmlns:d='http://docs.oasis-open.org/ws-dd/ns/discovery/2009/01'
xmlns:dp0='Com.myCompany.Services'>dp0:IMyServiceToProbe</d:Types>
        <Duration xmlns='http://schemas.microsoft.com/ws/2008/06/discovery'>PT5S
</Duration>
      </Probe>
    </s:Body>
  </s:Envelope>