- From: Jean Marc VANEL <jean-marc_vanel@effix.fr>
- Date: Thu, 17 Feb 2000 19:32:53 +0100
- To: David Wang <dwang@mitre.org>, xml-dev@xml.org, www-rdf-interest@w3.org, jmvanel@free.fr
In this search for Interoperability, I want to advocate for another way of linking things than Xlink: it's RDF. What is RDF's advantage compared to Xlink ? Instead of inventing new xlink attributes, e.g. this had been suggested: isA | hasA | equiv | isLike | partOf RDF allows to link two resources WITH ANY DOMAIN-DEFINED SEMANTICS. I'll give examples, and list afterwards the architectural implications. 1rst example: Express that yourElement in your XML Schema has the equivClass attribute with a value being myElement in my XML Schema (i.e. the two elements have same type). <rdf:RDF xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:xs ="http://www.w3.org/TR/1999/WD-xmlschema-1-19991217" > <rdf:Description about="http://yourCom.com/yourXMLSchema.xs#yourElement"> <xs:equivClass>http://myCom.com/myXMLSchema.xs#myElement</xs:equivClass> </rdf:Description> </rdf:RDF> 2nd example: One wants to mark a paragraph in a document as obsolete. <rdf:RDF xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:doc="http://myCom.com/documents.rdf"> <rdf:Description about="http://myCom.com/department/reports/2000-01.html#someParagraph"> <doc:status>obsolete</doc:status> </rdf:Description> </rdf:RDF> 3rd example: In mechanical construction, one wants to add information to a component defined in a geometrical CAD document about material, or supplier, etc. 4th example: In a Virtual Reality document, I could change the position or orientation of an object, and thus realize a movement or a sudden change in the scene. Architectural implications - the RDF document adding or modifying the subject resource can be either local and private, or published on a LAN or the Web; - the subject resource that is being described can be ANYWHERE. - the element or attribute in the "about" part of the RDF statement must be accessible as a URI; generally it will be marked with an attribute of XML ID type, but if Xpointer is supported, an XPath syntax is possible; - the domain-specific processors, (in the examples Schema processor, word processor, CAD processor) must be RDF-aware, that is able to read a set of rdf:Description , and apply the given properties to the given resources, if it knows about theses properties.
Received on Thursday, 17 February 2000 13:33:23 UTC