Re: Extended Relations + Constraints On Constraints proposal

> On 21 Jan 2017, at 06:10, Myles, Stuart <SMyles@ap.org> wrote:
> So, how would we express the XML equivalent of “c1 odrl:dependsOn c2”? You could add more attributes to the XML constraint, I suppose. Or you could introduce an a new XML element which lists the dependencies, e.g.

We have to utlise the id/idref tags in XML (which are already in defined in the xml schema).
An abbreviated example would be:

<o:Policy>
 …
  <o:permission>
     <o:asset uid=“photos” relation=“o:target”/>
     <o:action name=“o:distribute”/>
     <o:constraint name=“#c1" operator=“o:dependsOn” rightOperand=“#c2"
  </o:permission>
</o:Policy>
<o:constraint id=“c1” name=“o:event” operator=“o:eq” rightOperand=“football.com/manuVmanc”/ <http://football.com/manuVmanc%E2%80%9D/>>
<o:constraint id=“c2” name=“o:datetime” operator=“o:eq” rightOperand=“P30M”/ <http://football.com/manuVmanc%E2%80%9D/>>

We will then need to add a "processing rule” that says that if the constraint name starts with “#” (which it will not normally?) then it must refer to a constraint with such an id, and the rightOperand must also refer to a constraint with the same #id. (We will also need to add support in the xml schema for constraints outside the policy).

Renato