xml at work

XML at WorkJohn Arnett, MScStandards ModellerInformation and Statistics DivisionNHSScotlandTel: 0131 551 8073 (x2073)mailto:[email protected]://isdscotland.org/xml

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)


• XLink (XML Linking Language)

doc1doc1 doc2doc2

– Simple (unidirectional) links

doc3doc3doc2doc2doc1doc1

– Extended (multidirectional) links

– Language for linking resources


– 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

Application Logic

Application Logic

Presentation

PresentationPresentati

on

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 GovTalkTM 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)


– 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)


– 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)


– 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)


– Framework for indexing data and document resources using URI’s

– Consist of: •topics•associations•occurences

– XML Topic Maps (XTM) 1.0 Specification – ISO Standard 13250

• Topic Maps

The XML Standards Family

Adapted from http://www.idealliance.org/XMLRoadmap/WEB/xmlstdill.htm

SGML

HTML

XML Schema (XSDL)

XML

XML Core

CS

S

DO

M

XH

TM

L

XS

L &

XS

LT

XP

OIN

TER

&

XLIN

K

XQ

UER

Y

SO

AP

WS

DL

SV

G

WM

LC

DF

eb

XM

LC

ML

RDF

PIC

S

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– www.w3.org

Messaging and Web Sevices

• W3C Web Services Activity– www.w3.org/2002/ws/

• Web Services Interoperability– www.ws-i.org

• XMethods– www.xmethods.org/

• Enterprise Integration Patterns– www.enterpriseintegrationpatterns.c

om

XML Vocabularies

• Scottish Health and Community Care XML Steering Group– www.isdscotland.org/xml

• GovTalk Schemas and Standards– www.govtalk.gov.uk/schemasst

andards/schemasstandards.asp

• Health Level 7– www.hl7.org

XHTML and XSL

• W3C HyperText Markup Language (HTML) Home Page– www.w3.org/MarkUp/

• The Extensible Stylesheet Language Family (XSL)– www.w3.org/Style/XSL/

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