OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index]
'is-a' Relationships in XML?

There seems to be no shortage of ways, thankfully, to express 'has-a' relationships with XML (even without using a schema, it seems there is an implicit 'has' relationship between parent element and a child element or atttibute). There could be said to be an implicit semantic 'has' relationship declared between 'document' an 'date' when we write <document><date>...</date>...</document>. Is there any way to express the other key relationship of 'is-a' in XML? Is this something a schema language can express? Can we say that element (or even type) A 'is-an' element (or type) B? Any plans to add this 'feature' to the XML technologies if it isn't one already? It might be a key gap to fill. I might want to somehow imply that my <invoice/> is a <document/>. Are substitution groups (with, apparently, some inadequacies) the only way to express such a relationship in XML?

Best regards

Stephen D Green

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index]

News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 1993-2007 XML.org. This site is hosted by OASIS