On 07/01/2013 09:32, Bert Verhees wrote: > On 01/07/2013 02:40 AM, Thomas Beale wrote: >> > > I think, Thomas, the logic is as follows, the CSingleAttribute can, as > in the specs, have one or more then one children (CObjects). > Only one can be chosen, the others are alternatives. > > The CSingleAttribute can have existence 0..1 (OPTIONAL), 1..1 > (REQUIRED) and 0..0 (NOTALLOWED). > The last one I don't understand, why having an attribute as it is > defined to stay null.
this is used in ADL 1.5 templates to remove attributes not required in that particular data set (only if the RM permits it of course). > > But besides that, suppose you have a CSingleAttribute with REQUIRED > set with more CObjects as alternatives in it. > All occurrences for the CObjects need then to be set to 0..1, every > other setting is erroneous. > Occurrences 0..0 is useless, why define a CObject if it may never occur. > Occurrences 1..1 is useless, why define alternative CObjects if the > one chosen is defined. > > Maybe the occurrences of CObjects should not be looked at when child > of a CSingleAttribute occurrences can be 1..1 if it is the only possibility. occurrences can be 0..1 on two alternatives, with an additional rule that says that either A or B must be there (thus satisfying the 1..1 in the attribute itself) > ----- > It is that I am looking further in the world then existing archetypes. > We had the discussion about the tried enforcing top-down-structure of > archetypes and the consequences of this policy a few weeks ago. I'm not sure how this relates to the technical issue we are discussing here...? > > I am also looking further than the existing Java-libraries, but that I > will soon announce more about this. I am not claiming that the current specification approach is perfect. But the experience I know about elsewhere leads me to think it is pretty workable; we don't seem to have any problems in most tools or libraries on this issue. If there are aspects you are thinking about in some other kind of archetype, please share it, that would help. thanks - thomas
