- From: Roger L. Costello <costello@mitre.org>
- Date: Thu, 20 Jan 2000 15:56:43 -0500
- To: xml-dev@ic.ac.uk
- CC: www-xml-schema-comments@w3c.org, "Los,Michael E." <mel@mitre.org>, "Schneider,John C." <jcs@mitre.org>, "Cokus,Michael S." <msc@mitre.org>, "Costello,Roger L." <costello@mitre.org>
Hi Folks, I am interested in discussing what support XML Schemas provide for enabling interoperability. Below I present my understanding of the support that XML Schemas provide. If there are other ways that XML Schemas enable interoperability I would be interested in hearing them. ... Oftentimes in daily conversation there are several ways to express something. - For example, "The boys went hiking." or "The guys went hiking". . Thus, "boys" and "guys" are equivalent. Which word is used may depend upon what part of the country you live in, what mood you're in, or any number of factors. We would like to be able to express this "equivalence" capability in XML Schemas. - We would like to be able to declare in the schema an element called "boys", an element called "guys", and state that "guys" is equivalent to "boys". Thus, instance documents can use either "boys" or "guys", depending on their preference. With XML Schemas we can create an element (called the exemplar) and then create other elements which state that they are equivalent to the exemplar. For example, <element name="boys" type="string"/> <element name="guys" equivClass="friends:boys" type="string"/> XML Schemas enables us to explicitly state that guys is equivalent to boys. If I write an application which expects a <boys> element, and I get an XML document which contains a <guys> element then I can go to the XML Schema document to see if <guys> is equivalent to the expected <boys> element. Thus, the schema is acting as an "interoperability schema". A nice feature of the equivClass capability is that over time new elements can be added to the schema and declared to be equivalent to the <boys> element. For example, <element name="fellas" equivClass="friends:boys" type="string"/> Without any change, the application will continue to seemlessly work as it consults the interoperability schema for equivalences. Pretty cool, aye? /Roger
Received on Thursday, 20 January 2000 15:55:25 UTC