[OASIS Issue Tracker] Commented: (CMIS-139) Add namespace forproperty name

[OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org>]

    [ http://tools.oasis-open.org/issues/browse/CMIS-139?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=10147#action_10147 ] 

Florian Mueller commented on CMIS-139:
--------------------------------------

We are not far apart. Maybe the proposal isn't clear enough.

I think we agree that we need something like a namespace/prefix/package/marker concept that separates the CMIS base properties from type properties. Property names like "Name" and "ObjectId" are often used in real-world type definitions and conflict with the CMIS base properties.

The first question is if this marker is just a boolean (is or is not a CMIS base property) or a "group identifier string" that allows us to define multiple groups of somehow connected properties. The latter leaves us more options for following CMIS spec releases. It especially could support the aspects/mixins idea. It also helps repositories that support a hierarchical property system.

The next question is how to express this marker. You prefer an additional field and we think the property name should contain it.  I believe a concatenated string makes it easier for the client. It just had to set one property identification field instead of two and the property name should be opaque to the client anyway. The proposal says that if a repository doesn't support multiple groups the group identifier string can be empty. That is, the type property names stay untouched and just the CMIS base property names have to  be prefixed with a reserved group name such as "cmis:". Since the CMIS base properties names have to be mapped to the underlying repository anyway, this shouldn't be a burden for a CMIS implementation.

The final question is if those prefixes should work across types and therefore become real namespaces. As you pointed out this is related to the id attribute. Actually, for CMIS 1.0 I don't care. I don't believe there will be many use cases. It would be a nice-to-have for us.


> Add namespace for property name 
> --------------------------------
>
>                 Key: CMIS-139
>                 URL: http://tools.oasis-open.org/issues/browse/CMIS-139
>             Project: OASIS Content Management Interoperability Services TC
>          Issue Type: New Feature
>          Components: Domain Model
>    Affects Versions: Draft 0.50, Draft 0.6
>            Reporter: Florian Mueller
>            Assignee: Ethan Gur-esh
>
> Introducing namespaces provides the following advantages: 
> 1.  The CMIS specification defines a set of standard properties. An existing repository may have its own properties with the same names but with different semantics or different sets of constraints. A namespace allows clearly distinguishing between CMIS properties and repository or type specific properties. 
> 2.  Certain repositories allow using the same name of a property to be used at more than one place with a different meaning. Common property names like "Name" or "Invoice" might exist in different flavors an in different application contexts. 
> 3.  Future versions of the CMIS specifications may define additional standard properties (e.g. for Records Management). By introducing a separate namespace for the CMIS standard we can guarantee backward compatibility between a newer version of the specification and an existing repository or application implementation. 
> 4.  A namespace can be the foundation to introduce extended properties (e.g. hierarchies). Here are some relationships to other upcoming proposals, for example Aspects/Mixins that should be synchronized.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://tools.oasis-open.org/issues/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira