- From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
- Date: 10 Nov 2000 08:43:12 +0000
- To: "Jason Diamond" <jason@injektilo.org>
- Cc: <xmlschema-dev@w3.org>, www-xml-schema-comments@w3.org
"Jason Diamond" <jason@injektilo.org> writes: > I'm curious as to what the rationale was behind using the name attribute (on > the element, attribute, complexType, and simpleType elements) as the key for > referencing (via the ref, base, and type attributes). > > A schema document's {type definitions}, {attribute declarations} and > {element declarations} properties only contain items declared at the top > (global) level. These are the only items that can be referenced. Since id is > required to be unique throughout the document, regardless of whether it's a > global or nested item, couldn't it be used instead to uniquely identify both > definitions and declarations? > > This approach is not only more flexible (and not much more difficult to > implement) but also has the advantage that element declarations could be > included at the top level without artificially constraining it with > minOccurs="0" and maxOccurs="0" just so that you could reference it (if that > is indeed the case) from within multiple type definitions. Only > element/attribute declarations with a name would be part of the content > model. > > Type definitions wouldn't need a name which would (in my opinion) reduce the > confusion caused by multiple element and complexType elements who have name > attributes that only differ in the case of their first character. > > I'm sure there's plenty of good technical reasons for why things were done > using name instead. Thanks in advance for pointing them out. I'm not sure I understand all your points. The main reason we did _not_ use an attribute of type ID to name elements, types, attributes etc. is because that would have made it impossible to have e.g. a type and an attribute with the same name, which seemed to us unreasonably constraining. ht -- Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh W3C Fellow 1999--2001, part-time member of W3C Team 2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440 Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk URL: http://www.ltg.ed.ac.uk/~ht/
Received on Friday, 10 November 2000 03:43:19 UTC