Extension Handling 101: Example 4

OK, here it is. The extended Subscribe request that our mother always 
warned us about, Example 4:

<s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope"
            xmlns:wsa="http://www.w3.org/2005/08/addressing"
            xmlns:wse="http://www.w3.org/2009/02/ws-evt"
            xmlns:frq="http://www.refractory.org/timeDilation"
            xmlns:dev="http://www.smalldevices.org/evt-ext">
  <s:Header>
    <wsa:Action>http://www.w3.org/2009/02/ws-evt/Subscribe</wsa:Action>
    . . .
  </s:Header>
  <s:Body>
    <wse:Subscribe>
      <wse:Delivery>
        <wse:NotifyTo>
          <wsa:Address>http://www.example.com/MyEventSink/OnStormWarning</wsa:Address>
        </wse:NotifyTo>
**        <frq:Dilate>
          <frq:TimeScale useRelative="true">
            <frq:PhaseShift>-73.243</frq:PhaseShift>
          </frq>
          <frq:Margin>2009-07-07T15:27:26-0700</frq:Margin>
        </frq:Dilate>**
        *<dev:Pauseable>
          <dev:Duration>P3H</dev:Duration>
        </dev:Pauseable>
*      </wse:Delivery>
    </wse:Subscribe>
  </s:Body>
</s:Envelope>

It bends the mind! How can we possibly figure out how frq:Dilate and 
dev:Pauseable are supposed to interact? Will the time dilation shorten 
or lengthen the pause duration and, if so, by how much? But wait! We 
don't support frq:Dilate. Using the "power of ignorability" granted to 
us by the WS-Eventing spec, we can (nay SHOULD!) act as if frq:Dilate 
element *wasn't even there*! In which case we can create a pauseable 
Subscription (because we support that) and respond as we did in Example 3:

<s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope"
            xmlns:wsa="http://www.w3.org/2005/08/addressing"
            xmlns:wse="http://www.w3.org/2009/02/ws-evt"
            xmlns:dev="http://www.smalldevices.org/evt-ext">
 <s:Header>
    <wsa:Action>http://www.w3.org/2009/02/ws-evt/SubscribeResponse</wsa:Action>
    . . .
  </s:Header>
  <s:Body>
    <wse:SubscribeResponse>
      <wse:SubscriptionManager>
        <wsa:Address>
          http://www.example.org/oceanwatch/SubscriptionManager
        </wsa:Address>
      </wse:SubscriptionManager>
*      <dev:Pauseable>
        <dev:Duration>P1H</dev:Duration>
      </dev:Pauseable>*
    </wse:SubscribeResponse>
  </s:Body>
</s:Envelope>

And so concludes Example 4.

- gp