Re: [poe] Single vs. Collection of Asset and Party unclear

> @simonstey the tripwire of 2. is: it is not required that a used AssetCollection must list all of its "parts" in a policy. Therefore at the time of processing a Policy the processor does not know exactly if this asset thing thing has other Assets claiming they are a partOf it.

that's why we shouldn't adopt the Open World Assumption for evaluating/processing policies. otherwise, you also wouldn't know whether a policy is really linked to all of its rules, a rule is really listing all of its assignees, assigners, etc.

> Yes, that is correct. We can't really do anything about that...can we?

sticking to CWA for policy evaluation, i.e. everything that's not explicitly stated does not exist.

-------------------
fwiw, following SHACL shape can be used to check whether an asset conforms to the requirements of single assets (i.e., not of type AssetCollection and not partOf another Asset)
```turtle
odrl:SingleAssetShape
    a sh:NodeShape ;
    sh:targetNode ex:partB ; # replace ex:partB with the asset you want to check
    sh:not [ sh:class odrl:AssetCollection ] ;
    sh:property [
 sh:path odrl:partOf ;
 sh:maxCount 0 ;
    ] .
```

-- 
GitHub Notification of comment by simonstey
Please view or discuss this issue at https://github.com/w3c/poe/issues/195#issuecomment-311261029 using your GitHub account

Received on Tuesday, 27 June 2017 05:59:17 UTC