XML at Work John Arnett, MSc Standards Modeller Information and Statistics Division NHSScotland Tel: (x2073)

Contents XML Usage Enabling Technologies XML Applications –XML Messaging and Web Services –XML in Presentation –XML in Application Logic –XML Data Storage and Content Management

XML Usage –Human readable –Structured and searchable –Separates data from presentation –Self-describing –Extensible – any number of tags allowed –Meta-markup language Key features

XML Usage Open standard, promoted by many vendor-neutral organisations, incl. –W3C –OASIS (Organization for Structured Information Standards) –HL7 (Health Level 7) –OMG (Object Management Group) –UK Government

XML Usage Widely supported by software vendors and open source groups, incl.

Enabling Technologies –Language for locating parts of a document –Provides a syntax for navigating XML document trees –Designed for use by XSLT and XPointer XPath (XML Path Language)

Enabling Technologies XLink (XML Linking Language) doc1 doc2 –Simple (unidirectional) links doc3 doc2 doc1 –Extended (multidirectional) links –Language for linking resources

Enabling Technologies –Language for referencing specific points in a document –Uses XPath –May be used with XLink to reference specific points in linked documents XPointer (XML Pointer Language)

XML Applications Data Storage & Content Management Application Logic Presentation Messaging & Web Services Messaging

–Ideal for data interchange Text based Open Self describing Extensible –Exchanged between applications on the same network or over the Internet/Extranet XML Messaging XML Messages

XML Messaging –Health Care Health Level 7, v3 –Government UK GovTalk TM schemas –B2B transactions ebXML –Financial Services reporting XBRL XML Business Vocabularies, e.g.

Web Services Allow systems to communicate over the internet using XML messages Used for –remote lookups and service calls –enterprise application integration –electronic B2B exchange Set of emerging standards, incl. SOAP, WSDL and UDDI

Web Services –Lightweight, XML–based protocol for exchanging information over the internet –Language, platform and transport independent –v1.2 W3C Recommendation SOAP (“Simple Object Access Protocol”)

Web Services –XML-based language for describing services available on the internet WSDL (Web Services Definition Language)

Web Services –Information Services business details (white pages) business categories (yellow pages) available services (green pages) –Operations service registration finding and using services UDDI (Universal Description, Discovery and Integration) directory services

XML for Presentation –Developed by WC3 as XML-based successor to HTML –Written using well-formed XML –Backwards compatible –Current version (1.1) designed to be extended using modules XHTML (Extensible HTML)

XML for Presentation –Enables XML to be presented in other XML or non-XML formats – esp. as HTML –v1.0 W3C Recommendation –Can be used to create dynamic web-forms, e.g. WSDL to HTML XSL (Extensible Stylesheet Language)

XML for Presentation –WML (Wireless Markup Language) for mobile devices –SVG (Scaleable Vector Graphics) –Scientific vocabularies CML (Chemical Markup Language) MathML (Mathematical Markup Language) Other XML presentation technologies

XML in Application Logic DOM (Document Object Model) –API for in-memory document manipulation using a node-based tree structure

XML in Application Logic SAX (Simple API for XML) –Alternative, event-driven API, used for parsing large documents

XML Data Storage –Web and file servers –XML enabled databases –Native XML repositories/databases Document storage solutions incl.

XML Data Storage –Enables SQL-like querying of XML documents using XPath –W3C Working draft XQuery

XML & Content Management –W3C recommendation for describing information contained in web resources i.e. anything that can be addressed with a URL –Dublin Core is an RDF vocabulary for describing web pages RDF (Resource Description Framework)

XML & Content Management –Used to automatically send (or push) web content to subscribers e.g. subscibers can obtain regular news updates from a news website –RSS (Rich Site Summary) is a smilar application developed by Netscape Microsoft CDF (Channel Definition Format)

XML & Content Management –Framework for indexing data and document resources using URI’s –Consist of: topics associations occurences –XML Topic Maps (XTM) 1.0 Specification – ISO Standard Topic Maps

The XML Standards Family Adapted from SGML HTML XML Schema (XSDL) XML XML Core CSS DOM XHTML XSL & XSLT XPOINTER & XLINK XQUERY SOAP WSDL SVG WML CDF ebXML CML RDF PICS P3P

In Summary… Open standard, widely supported by many organisations Applications include –Messaging and web services –Presentation and application logic –Data storage and content management

Find Out More World Wide Web Consortium –

Messaging and Web Sevices W3C Web Services Activity – Web Services Interoperability – XMethods – Enterprise Integration Patterns –

XML Vocabularies Scottish Health and Community Care XML Steering Group – GovTalk Schemas and Standards – ards/schemasstandards.aspwww.govtalk.gov.uk/schemasstand ards/schemasstandards.asp Health Level 7 –

XHTML and XSL W3C HyperText Markup Language (HTML) Home Page – The Extensible Stylesheet Language Family (XSL) –