tmpl-template.xml

<config-template xmlns="http://tail-f.com/ns/config/1.0"
                 servicepoint="tmpl">
  <resource-pools xmlns="http://cisco.com/yang/nso/resource-allocator">

<!-- This part does the allocation, the pool name is fixed, but the allocation is set to the current name
     of the service -->    
  <id-pool>
    <name>pool1</name>
      <allocation>
        <id>{./name}</id>
        <allocating-service xmlns:tmpl="http://com/example/tmpl">/tmpl:tmpl[tmpl:name='{./name}']</allocating-service>
      </allocation>
  </id-pool>
  </resource-pools>

<!-- We want to do our change only if the allocation is ready -->
<devices xmlns="http://tail-f.com/ns/ncs">

<!-- This is a little bit of a hack to find our allocation, if it exists. 

We should really look at /ralloc:resource-pools/ralloc:id-pool[ralloc:name='pool1']/allocation[id='t1']/response, but I couldn't make that work the way I wanted. -->
<?set-root-node {/}?>
<?set myref = {concat('/tmpl:tmpl\{',./name,'\}')}?>
<?set val = {/id-allocator/pool[name='pool1']/allocation[owner=$myref]}?>
<!-- Then we make a conditional based on if the value is there yet or not -->
<?if {$val}?>
    <device>
      <name>{./device}</name>
      <config>
        <sys xmlns="http://example.com/router">
          <interfaces>
            <interface>
              <name>eth{$val}</name>
              <description>Interface {$val}</description>
            </interface>
          </interfaces>
        </sys>
      </config>
    </device>
<?end?> 
  </devices>
</config-template>