Sheet 1XML Technology in E-Commerce 2001 Lecture 8

XML Technology in E-Commerce

Lecture 8

Current Developments in the XML World

Sheet 2XML Technology in E-Commerce 2001 Lecture 8

• XML Information Set;

• Semantic Web and RDF;• Modularization;• Composite Capabilities/Preference Profile

(CC/PP);• XML Query Language;• Web Services;• Composable XML;

Outline

Sheet 3XML Technology in E-Commerce 2001 Lecture 8

XML Infoset• Several logical models for XML documents:

– DOM;

– XPath;

– XPointer;

• XML Information Set (Infoset) defines abstract data model for XML documents;

• Other specifications will refer to the XML Infoset;

• Model - a hierarchy of information items with named properties and their values;

• Different applications can extend the initial infoset (Schema processor, XLink processor, etc.);

• Resources - http://www.w3.org/TR/xml-infoset;

Sheet 4XML Technology in E-Commerce 2001 Lecture 8

Semantic Web• Goal - representation of machine understandable

data on the Web;• Technologies:

– Resource Description Framework (RDF)

– Ontologies (Vocabularies of concepts organized in a hierarchy);

– Inference mechanism;

• Resources - http://www.w3.org/2001/sw/

Subject ObjectPredicate

RDF Statement Model

Sheet 5XML Technology in E-Commerce 2001 Lecture 8

Modularization XHTML

• XHTML (http://www.w3.org/MarkUp/):– Reformulation of HTML in XML;

– Framework for creation of language families based on XHTML;

– Subsets and supersets of XHTML;

– Module is a definition of element and attribute names and types and element content models;

• Modules for:– Text, List, Tables;

– Images, Applets;

– Forms, Style;

Sheet 6XML Technology in E-Commerce 2001 Lecture 8

ModularizationSMIL

• Synchronized Multimedia Integration Language (SMIL), http://www.w3.org/AudioVideo/;

• Modules for:– Animation;

– Timing;

– Transitions;

– Animation Effects;

– Layout;

– Media Elements;

Sheet 7XML Technology in E-Commerce 2001 Lecture 8

ModularizationHybrid Languages

XHTML SMILSVGMathML

Table Text

ListImage

TimingAnimation

Effects

XHTML SubsetTable Text

List

XHTML

Timing

XHTML

SVG++

• Hybrid Document - incorporates elements from multiple vocabularies;

• New document languages can be developed by composing multiple modules;

Sheet 8XML Technology in E-Commerce 2001 Lecture 8

Authoring for Multiple Target Devices

XMLDocument

Desktop Browser

Palm

Mobile Phone

Voice Generator

Web content is intended for multiple consumer devices with different capabilities

Sheet 9XML Technology in E-Commerce 2001 Lecture 8

CC/PP

• Composite Capabilities/Preference Profile (CC/PP);• CC/PP provides vocabulary for client features

specification;• Client and server can negotiate the content on the

base of CC/PP descriptions;• Server can adapt the content for different clients,

e.g. on the base of supported modules;• CC/PP will be RDF application;• Resources - http://www.w3.org/Mobile/CCPP/;

Sheet 10XML Technology in E-Commerce 2001 Lecture 8

XML Query Language• Purpose - language for query specification that

extracts data from XML documents;• Required specifications:

– Data model;

– Query algebra;

– Query language;

• Query languages:– XQL;

– XML Query;

– XQuery (work in progress in W3C);

• Resources - http://www.w3.org/XML/Query;

Sheet 11XML Technology in E-Commerce 2001 Lecture 8

Web Services• WWW:

– Today: resources intended for human consumption;

– In the future: composition of modular services, with machine understandable information;

• Web service - collection of functions accessible from network through standard protocol;

• Related technologies:– UDDI - Universal Discovery, Description and

Integration;

– WSDL - Web Services Description Language;

– SOAP - Simple Object Access Protocol;

Sheet 12XML Technology in E-Commerce 2001 Lecture 8

Composable XML

S1

S2

S3

Schema

D1

D2

D3

XML Document

I1

I2

I3

Interpreter

HTMLModules

ExamSchema

Timing

QuestionContent

ExamStructure

Timesheet

Renderer

Exam Objects

Scheduler

Sheet 13XML Technology in E-Commerce 2001 Lecture 8

Composable XML• Based on:

– Recent modularization technology;

– XML interpretation techniques;

– Advanced software composition techniques (Composition Filters, Aspect Orientation);

• Intended to cope with evolution and adaptation problems with XML documents and the corresponding software;

• Can be used for generic “browsers” for a family of languages in a certain problem domain (Web, eCommerce);

• Project home - http://trese.cs.utwente.nl/composable_xml/

Sheet 14XML Technology in E-Commerce 2001 Lecture 8

Conclusion

XMLXML Namespaces

XPathXPointerXSLTXLink

XML Schema

XML Languages

Parser

DOMSAX

Software Application

XSL FO

Data Binding Facility

XML Infoset

RDFCC/PP

XHTMLSMIL

XQuery

SOAPWSDL

UDDI

Web Services

Architectures