Hi everyone, I've been studying how to simplify the ITEM_STRUCTURE model to enhance the persistence performance of our Open EHR-Gen project (http://code.google.com/p/open-ehr-gen-framework).
Now I'm reaching a point in which I doubt about the necessity of ITEM_SINGLE in the RM (as a subclass of ITEM_STRUCTURE) and I want to expose some arguments and hear your comments about it. Semantic argument: As I understand ITEM_SINGLE, the semantics of this class are the same as an ITEM_LIST or ITEM_TREE with only one ELEMENT, I mean that: the semantics of ITEM_SINGLE is just a matter of cardinality (=1). Practical argument: in practice, an ITEM_SINGLE is like using an ELEMENT as an ITEM_STRUCTURE. And if we have only TREEs, LISTs and TABLEs, the interface of each class can be the same, like: getItems(), setItems(), the ITEM_SINGLE breaks that with getItem() and setItem(). Evolution argument: If I have an archetype with an ITEM_SINGLE, but the concept modeled with this archetype needs to change adding more nodes to the archetype, I need to change the ITEM_SINGLE to another ITEM_STRUCTURE, but if the archetype is modeled with an ITEM_TREE, I can add any nodes without changing the ITEM_STRUCTURE type. I think this way is more simple to create new archetypes with backwards compatibility. What do you think? -- Kind regards, Ing. Pablo Pazos Guti?rrez LinkedIn: http://uy.linkedin.com/in/pablopazosgutierrez Blog: http://informatica-medica.blogspot.com/ Twitter: http://twitter.com/ppazos -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openehr.org/mailman/private/openehr-technical_lists.openehr.org/attachments/20111003/732ac796/attachment.html>
