[Standards-JIG] JEP-0060 Publisher Model - node hirarchy permissions

[Ralph Meijer]

On Wed, May 24, 2006 at 05:00:17PM +0200, bernhard wrote:
> Thank you very much for the answer.
> Now I have new questions about collection nodes
> >>2.) A collection is similar to a directory in file system - do we need 
> >>that?
> >>    
> >
> >We have explicitely not defined how node hierarchies are set up.
> >Directories in file systems in general assume a tree like structure. We
> >assume a directed multigraph without cycles with the addition of a
> >virtual root node that comprises all (leaf and collection) nodes at a
> >service.
> >  
> The hierachie is not defined by the jep.
> But then I don't understand
> 9.4 Creating Nodes Affiliated with a Collection
> 
> Is it possible that a node/collection is "child" of more than one 
> collection?

Yes. See [1]

> Shouldn't it be possible to assign an existing node to a collection? - 

It is, by changing a collection node's configuration.

> otherwise it is a tree

No, it might be several. Also, as I mentioned, there is the root node
that is special in that it contains all nodes in a service.

> How to prevent cycles? Is it a task of the system or the user?

I suppose it is in the best interest of the service implementation to
safe-guard against cycles (because you otherwise get notification
loops), and of the entity creating the graph structure by adding nodes
to collections.

[1] http://en.wikipedia.org/wiki/Node_(computer_science)

-- 
Groetjes,

ralphm