Dear all I am coming back to an earlier question (http://lists.openehr.org/pipermail/openehr-technical_lists.openehr.org/2012q2/007100.html) because i am reaching the point where i am performing validation and i really need to verify (now rather than later) how some things are supposed to be working.
I am noticing that C_OBJECTs have "occurrences" and C_ATTRIBUTEs have "existence" and "cardinality" but i don't understand what does that mean for ITEM_STRUCTURE and also when you put them together. My questions therefore are as follows: 1) When creating an archetype for some RM entity that contains some form of archetypeable "items" attribute (list, set) then the cardinality constraint refers to that List<ITEM_STRUCTURE> that constitutes the "items" attribute). For example, if i define an ordered CLUSTER with two fields and max cardinality 8 (0..7 lower included), then i expect "items" to contain UP TO 8 pairs of these fields. Is that correct? (I think so) 2) Why then is there a "cardinality" on an ITEM_STRUCTURE AND an "occurrence" on each of its contents at the same time? For example, i can define an ordered CLUSTER of cardinality 4, containing one DV_TEXT (as an example) with up to 15 occurrences....The way i understand this is that i have just defined a list of 4 items each of which is a CLUSTER that contains one text field that itself is a list of 45 entries. I don't think that this agrees with the RM definition though because an ELEMENT's "value" can hold just ONE DATA_VALUE....What does this "occurrence" means then? This is getting a bit confusing when you consider what happens with CLUSTERs containing CLUSTERs (either nested or linked through SLOTs) In this case, i can have a CLUSTER (that will have a cardinality of its own) containing another CLUSTER with (occurrence.max>1 AND a cardinality.max>1) :-? If you have CLUSTERs with high cardinalities you can already define a tree (CLUSTER.items[0].items[1].items[3].items[4]....), so how do occurrences fit in there as well? Looking forward to hearing from you Athanasios Anastasiou
