XML schema languages: beyond DTD

DemetriosIoannides1
1Demetrios Ioannides is based at the Michigan State University, East Lansing, MI, USA. [email protected]

Tóm tắt

The flexibility and extensibility of XML have largely contributed to its wide acceptance beyond the traditional realm of SGML. Yet, there is still one more obstacle to be overcome before XML is able to become the evangelized universal data/document format. The obstacle is posed by the limitations of the legacy standard for constraining the contents of an XML document. The traditionally used DTD (document type definition) format does not lend itself to be used in the wide variety of applications XML is capable of handling. The World Wide Web Consortium (W3C) has charged the XML schema working group with the task of developing a schema language to replace DTD. This XML schema language is evolving based on early drafts of XML schema languages. Each one of these early efforts adopted a slightly different approach, but all of them were moving in the same direction.

Từ khóa


Tài liệu tham khảo

Allen, D. (1998), “New directions for EDI”, Telecommunications, November.

DuCharme, B. (1998), “Automating SGML‐to‐XML DTD conversion”, parts 1 and 2, October and November, <TAG>.

“Extensible markup language (XML) 1.0: W3C Recommendation”, 10 February 1998, Available: http://www.w3.org/TR/REC‐xml.

Karpinski, R. (1998), “Databases, tools push XML into enterprise”, Internetweek, 16 November.

Karpinski, R. (1999), “XML name spec to help avoid ambiguity”, InternetWeek, 25 January.

Lassila, O. and Swick, R. (1999), “Resource description framework (RDF) model and syntax specification”, 22 February. Available: http://www.w3.org/TR/REC‐rdf ‐syntax.

Miller, E. (1998), “An introduction to the resource description framework”, Bulletin of the American Society for Information Science, October/November, Washington, DC.

Milstead, J. and Feldman, S. (1999), “Metadata” Online, January/February, pp. 32‐40.

“Namespaces in XML: World Wide Web consortium”, 14 January 1999, Available: http://www.w3.org/TR/ REC‐xml‐names.

Radosevich, L. (1997), “XML à la Microsoft: company eyes new markup format”, InfoWorld, 1 September.

Radosevich, L. (1997), “XML initiatives take shape”, InfoWorld, 15 September.

Walsh, J. (1999), “XML poses data‐architecture debate”, InfoWorld, 25 January.

“XML schema requirements: W3C note”, 15 February 1999, Available: http://www.w3.org/TR/NOTE‐xml‐schema ‐req

“XHTML 1.0: the extensible hypertext markup language: a reformulation of HTML 4.0 in XML 1.0”, 24 February 1999, Available: http://www.w3.org/TR/WD‐html‐in‐ xml