Changes between Version 10 and Version 11 of CMDI 1.2/Vocabularies

Timestamp:

01/16/14 14:35:14 (10 years ago)

Author:

twagoo

Comment:

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CMDI 1.2/Vocabularies

@@ -189 +189 @@
 '''Open vs. closed vocabularies'''
 As far as I understand, whether a vocabulary is open or closed represents - in this context at least -  merely a ''mode of application'',- it is not a feature of the vocabulary as such. Maybe I am missing something, but I fail to see the sense in  treating open and closed vocabularies differently in the way proposed here. More specifically.  I question the wisdom of snapshotting (possibly huge) vocabularies into the components and profiles. After all, the vocabularies are not static, and how do we make sure that the vocabulary copies are kept updated? My guess is that this - after a time - will result in as many vocabulary variants as there are components using it. So why not referring to closed vocabularies the same ways as open? The we probably need to encode in another way whether the vocabulary is to be used in a closed or open way.  
+
+ Twan: I can see how this is not entirely clear. The first distinction we can make is external/internal vocabularies. Internal vocabularies (which is the only type we have in 1.1) can only be closed because they are expressed as choice in XSD and have implications for the validation. External vocabularies could conceptually be applied either way, which I think is the point you are trying to make. However giving an external vocabulary a closed status does not strictly limit a user to use its values, i.e. there is no straightforward validation mechanism. The best thing that could be achieved realistically is for this to make the editing tool(s) limit the entry to items in the vocabulary. Hence in the proposal the distinction external/internal is equivalent to the distinction open/closed. But we can of course consider a 'semi-closed' variant for external vocabularies.
+
 Another thing: Would it be useful to be able to select from a ''union of vocabularies'', instead of just one? True, such a need could be satisfied by choosing one vocabulary and declaring it open.  But if all the additional items are to selected from another vocabulary, it would be nice to be able to say so.