Standards in Information Management: XML

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Standards in Information Management XML

• Arijit Sengupta

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Learning Objectives

• Learn what XML is
• Learn the various ways in which XML is used
• Learn the key companion technologies
• See how XML is being used in industry as a
  meta-language

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Agenda

• Overview
• Syntax and Structure
• The XML Alphabet Soup
• XML as a meta-language

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OverviewWhat is XML?

• A tag-based meta language
• Designed for structured data representation
• Represents data hierarchically (in a tree)
• Provides context to data (makes it meaningful)
• Self-describing data
• Separates presentation (HTML) from data (XML)
• An open W3C standard
• A subset of SGML
• vs. HTML, which is an implementation of SGML

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OverviewWhat is XML?

• XML is a use everywhere data specification

XML
XML
XML
XML
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OverviewDocuments vs. Data

• XML is used to represent two main types of
  things
• Documents
• Lots of text with tags to identify and annotate
  portions of the document
• Data
• Hierarchical data structures

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OverviewXML and Structured Data

• Pre-XML representation of data
• XML representation of the same data

PO-1234,CUST001,X9876,5,14.98
ltPURCHASE_ORDERgt ltPO_NUMgt PO-1234
lt/PO_NUMgt ltCUST_IDgt CUST001 lt/CUST_IDgt ltITEM_NUM
gt X9876 lt/ITEM_NUMgt ltQUANTITYgt 5
lt/QUANTITYgt ltPRICEgt 14.98 lt/PRICEgt lt/PURCHASE_ORD
ERgt
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OverviewBenefits of XML

• Open W3C standard
• Representation of data across heterogeneous
  environments
• Cross platform
• Allows for high degree of interoperability
• Strict rules
• Syntax
• Structure
• Case sensitive

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OverviewWho Uses XML?

• Submissions by
• Microsoft
• IBM
• Hewlett-Packard
• Fujitsu Laboratories
• Sun Microsystems
• Netscape (AOL), and others
• Technologies using XML
• SOAP, ebXML, BizTalk, WebSphere, many others

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Agenda

• Overview
• Syntax and Structure
• The XML Alphabet Soup
• XML as a meta-language

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Syntax and StructureComponents of an XML Document

• Elements
• Each element has a beginning and ending tag
• ltTAG_NAMEgt...lt/TAG_NAMEgt
• Elements can be empty (ltTAG_NAME /gt)
• Attributes
• Describes an element e.g. data type, data range,
  etc.
• Can only appear on beginning tag
• Processing instructions
• Encoding specification (Unicode by default)
• Namespace declaration
• Schema declaration

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Syntax and StructureComponents of an XML Document

• lt?xml version1.0 ?gt
• lt?xml-stylesheet type"text/xsl
  hreftemplate.xsl"?gt
• ltROOTgt
• ltELEMENT1gtltSUBELEMENT1 /gtltSUBELEMENT2
  /gtlt/ELEMENT1gt
• ltELEMENT2gt lt/ELEMENT2gt
• ltELEMENT3 typestringgt lt/ELEMENT3gt
• ltELEMENT4 typeinteger value9.3gt
  lt/ELEMENT4gt
• lt/ROOTgt

Elements with Attributes
Elements
Prologue (processing instructions)
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Syntax and StructureRules For Well-Formed XML

• There must be one, and only one, root element
• Sub-elements must be properly nested
• A tag must end within the tag in which it was
  started
• Attributes are optional
• Defined by an optional schema
• Attribute values must be enclosed in or
• Processing instructions are optional
• XML is case-sensitive
• lttaggt and ltTAGgt are not the same type of element

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Syntax and StructureWell-Formed XML?

• No, CHILD2 and CHILD3 do not nest properly

ltxml? Version1.0 ?gt ltPARENTgt ltCHILD1gtThis is
element 1lt/CHILD1gt ltCHILD2gtltCHILD3gtNumber
3lt/CHILD2gtlt/CHILD3gt lt/PARENTgt
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Syntax and StructureWell-Formed XML?

• No, there are two root elements

ltxml? Version1.0 ?gt ltPARENTgt ltCHILD1gtThis is
element 1lt/CHILD1gt lt/PARENTgt ltPARENTgt ltCHILD1gtThi
s is another element 1lt/CHILD1gt lt/PARENTgt
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Syntax and StructureWell-Formed XML?

• Yes

ltxml? Version1.0 ?gt ltPARENTgt ltCHILD1gtThis is
element 1lt/CHILD1gt ltCHILD2/gt ltCHILD3gtlt/CHILD3gt lt
/PARENTgt
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Syntax and StructureAn XML Document
lt?xml version'1.0'?gt ltbookstoregt ltbook
genreautobiography publicationdate1981
ISBN1-861003-11-0gt lttitlegtThe
Autobiography of Benjamin Franklinlt/titlegt
ltauthorgt ltfirst-namegtBenjaminlt/first-namegt
ltlast-namegtFranklinlt/last-namegt
lt/authorgt ltpricegt8.99lt/pricegt lt/bookgt
ltbook genrenovel publicationdate1967
ISBN0-201-63361-2gt lttitlegtThe Confidence
Manlt/titlegt ltauthorgt ltfirst-namegtHermanlt
/first-namegt ltlast-namegtMelvillelt/last-namegt
lt/authorgt ltpricegt11.99lt/pricegt
lt/bookgt lt/bookstoregt
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Syntax and Structure Namespaces Overview

• Part of XMLs extensibility
• Allow authors to differentiate between tags of
  the same name (using a prefix)
• Frees author to focus on the data and decide how
  to best describe it
• Allows multiple XML documents from multiple
  authors to be merged
• Identified by a URI (Uniform Resource Identifier)
• When a URL is used, it does NOT have to represent
  a live server

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Syntax and Structure Namespaces Declaration
Namespace declaration examples
xmlns bk http//www.example.com/bookinfo/
xmlns bk urnmybookstuff.orgbookinfo
xmlns bk http//www.example.com/bookinfo/
Namespace declaration
Prefix
URI (URL)
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Syntax and Structure Namespaces Examples
ltBOOK xmlnsbkhttp//www.bookstuff.org/bookinfo
gt ltbkTITLEgtAll About XMLlt/bkTITLEgt
ltbkAUTHORgtJoe Developerlt/bkAUTHORgt ltbkPRICE
currencyUS Dollargt19.99lt/bkPRICEgt
ltbkBOOK xmlnsbkhttp//www.bookstuff.org/bookin
fo xmlnsmoneyurnfinancemoneygt
ltbkTITLEgtAll About XMLlt/bkTITLEgt
ltbkAUTHORgtJoe Developerlt/bkAUTHORgt ltbkPRICE
moneycurrencyUS Dollargt
19.99lt/bkPRICEgt
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Syntax and Structure Namespaces Default
Namespace

• An XML namespace declared without a prefix
  becomes the default namespace for all
  sub-elements
• All elements without a prefix will belong to the
  default namespace

ltBOOK xmlnshttp//www.bookstuff.org/bookinfogt
ltTITLEgtAll About XMLlt/TITLEgt ltAUTHORgtJoe
Developerlt/AUTHORgt
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Syntax and Structure Namespaces Scope

• Unqualified elements belong to the inner-most
  default namespace.
• BOOK, TITLE, and AUTHOR belong to the default
  book namespace
• PUBLISHER and NAME belong to the default
  publisher namespace

ltBOOK xmlnswww.bookstuff.org/bookinfogt
ltTITLEgtAll About XMLlt/TITLEgt ltAUTHORgtJoe
Developerlt/AUTHORgt ltPUBLISHER
xmlnsurnpublisherspublinfogt
ltNAMEgtMicrosoft Presslt/NAMEgt
lt/PUBLISHERgt lt/BOOKgt
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Syntax and Structure Namespaces Attributes

• Unqualified attributes do NOT belong to any
  namespace
• Even if there is a default namespace
• This differs from elements, which belong to the
  default namespace

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Syntax and Structure Entities

• Entities provide a mechanism for textual
  substitution, e.g.
• You can define your own entities
• Parsed entities can contain text and markup
• Unparsed entities can contain any data
• JPEG photos, GIF files, movies, etc.

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Agenda

• Overview
• Syntax and Structure
• The XML Alphabet Soup
• XML as a meta-language

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The XML Alphabet Soup

• XML itself is fairly simple
• Most of the learning curve is knowing about all
  of the related technologies

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The XML Alphabet Soup
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The XML Alphabet Soup
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The XML Alphabet Soup Schemas Overview

• DTD (Document Type Definitions)
• Not written in XML
• No support for data types or namespaces
• XSD (XML Schema Definition)
• Written in XML
• Supports data types
• Current standard recommended by W3C

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The XML Alphabet Soup Schemas Purpose

• Define the rules (grammar) of the document
• Data types
• Value bounds
• A XML document that conforms to a schema is said
  to be valid
• More restrictive than well-formed XML
• Define which elements are present and in what
  order
• Define the structural relationships of elements

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The XML Alphabet Soup Schemas DTD Example

• XML document
• DTD schema

ltBOOKgt ltTITLEgtAll About XMLlt/TITLEgt
ltAUTHORgtJoe Developerlt/AUTHORgt lt/BOOKgt
lt!DOCTYPE BOOK lt!ELEMENT BOOK (TITLE, AUTHOR)
gt lt!ELEMENT TITLE (PCDATA) gt lt!ELEMENT
AUTHOR (PCDATA) gt gt
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The XML Alphabet Soup Schemas XSD Example

• XML document

ltCATALOGgt ltBOOKgt ltTITLEgtAll About
XMLlt/TITLEgt ltAUTHORgtJoe Developerlt/AUTHORgt
lt/BOOKgt lt/CATALOGgt
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The XML Alphabet Soup Schemas XSD Example
ltxsdschema id"NewDataSet targetNamespace"http
//tempuri.org/schema1.xsd" xmlns"http//tempu
ri.org/schema1.xsd" xmlnsxsd"http//www.w3.o
rg/1999/XMLSchema" xmlnsmsdata"urnschemas-mi
crosoft-comxml-msdata"gt ltxsdelement
name"book"gt ltxsdcomplexType
content"elementOnly"gt ltxsdallgt
ltxsdelement name"title" minOccurs"0"
type"xsdstring"/gt ltxsdelement
name"author" minOccurs"0" type"xsdstring"/gt
lt/xsdallgt lt/xsdcomplexTypegt
lt/xsdelementgt ltxsdelement nameCatalog"
msdataIsDataSet"True"gt ltxsdcomplexTypegt
ltxsdchoice maxOccurs"unbounded"gt
ltxsdelement ref"book"/gt lt/xsdchoicegt
lt/xsdcomplexTypegt lt/xsdelementgt lt/xsdschemagt
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The XML Alphabet Soup Schemas Why You Should
Use XSD

• Newest W3C Standard
• Broad support for data types
• Reusable components
• Simple data types
• Complex data types
• Extensible
• Inheritance support
• Namespace support
• Ability to map to relational database tables
• XSD support in Visual Studio.NET

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The XML Alphabet Soup Transformations XSL

• Language for expressing document styles
• Specifies the presentation of XML
• More powerful than CSS
• Consists of
• XSLT
• XPath
• XSL Formatting Objects (XSL-FO)

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The XML Alphabet Soup Transformations Overview

• XSLT a language used to transform XML data into
  a different form (commonly XML or HTML)

XML
XML,HTML,
XSLT
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The XML Alphabet Soup Transformations XSLT

• The language used for converting XML documents
  into other forms
• Describes how the document is transformed
• Expressed as an XML document (.xsl)
• Template rules
• Patterns match nodes in source document
• Templates instantiated to form part of result
  document
• Uses XPath for querying, sorting, etc.

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The XML Alphabet Soup XPath (XML Path Language)

• General purpose query language for identifying
  nodes in an XML document
• Declarative (vs. procedural)
• Contextual the results depend on current node
• Supports standard comparison, Boolean and
  mathematical operators (, lt, and, or, , , etc.)

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The XML Alphabet Soup XPath Operators
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The XML Alphabet Soup XPath Query Examples
./author (finds all author elements within
current context) /bookstore (find the bookstore
element at the root) / (find the root
element) //author (find all author elements
anywhere in document) /bookstore_at_specialty
textbooks (find all bookstores where the
specialty attribute
textbooks) /book_at_style /bookstore/_at_specialty
(find all books where the style
attribute the specialty attribute
of the bookstore element at the root)
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More XPath Examples
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XPath Functions

• Accessor functions
• node-name, data, base-uri, document-uri
• Numeric value functions
• abs, ceiling, floor, round,
• String functions
• compare, concat, substring, string-length,
  uppercase, lowercase, starts-with, ends-with,
  matches, replace,
• Other functions include functions on boolean
  values, dates, nodes, etc.

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The XML Alphabet Soup Data Islands

• XML embedded in an HTML document
• Manipulated via client side script or data binding

ltXML idXMLIDgt ltBOOKgt ltTITLEgtAll About
XMLlt/TITLEgt ltAUTHORgtJoe Developerlt/AUTHORgt
lt/BOOKgt lt/XMLgt ltXML idXMLID
srcmydocument.xmlgt
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The XML Alphabet Soup Data Islands

• Can be embedded in an HTML SCRIPT element
• XML is accessible via the DOM

ltSCRIPT languagexml idXMLIDgt ltSCRIPT
typetext/xml idXMLIDgt ltSCRIPT
languagexml idXMLID
srcmydocument.xmlgt
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The XML Alphabet Soup XML-Based Applications

• Microsoft SQL Server
• Retrieve relational data as XML
• Query XML data
• Join XML data with existing database tables
• Update the database via XML Updategrams
• New XML data type in SQL 2005
• Microsoft Exchange Server
• XML is native representation of many types of
  data
• Used to enhance performance of UI scenarios (for
  example, Outlook Web Access (OWA))

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Agenda

• Overview
• Syntax and Structure
• The XML Alphabet Soup
• XML as a meta-language

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XML as a Meta-Language
A Language to create Languages
CSS
SAX
DOM
DSSL
XSL
XML/DTD
XLL
XSLT
GO
XSchema
CML
XPath
MathML
WML
XPointer
BeanML
XQL
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Gene Ontology (GO)

• Describing and manipulating information about the
  molecular function, biological process and
  cellular component of gene products.
• Gene Ontology website
• http//www.geneontology.org
• GO DTD
• ftp//ftp.geneontology.org/pub/go/xml/dtd/go.dtd
• GO Browsers and tools
• http//www.geneontology.org/tools
• GO Resources and samples
• http//www.geneontology.org/annotations

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Math ML

• Describing and manipulating mathematical
  notations
• MathML website
• www.w3.org/Math
• MathML DTD
• www.w3.org/Math/DTD
• MathML Browser
• www.w3.org/Amaya
• MathML Resources
• www.webeq.com/mathml see sample documents here

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Chemical ML

• Representing molecular and chemical information
• CML website
• www.xml-cml.org
• CML DTD
• www.xml-cml.org/dtdschema/index.html
• CML Browser and Authoring Environment
• www.xml-cml.org/jumbo.html
• CML Resources
• www.xml-cml.org/chimeral/index.html
• see sample documents here
• some require plug-in downloads, can be slow

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Wireless ML

• Allows web pages to be displayed over mobile
  devices
• WML works with WAP to deliver the content
• Underlying model Deck of Cards that the User can
  sift through
• WAP/WML website
• www.wapforum.org
• WML DTD
• www.wapforum.org/DTD/wml_1.1.xml
• WAP/WML Resources
• www.oasis-open.org/cover/wap-wml.html
• www.w3scripts.com/wap Tutorial on WML, also see
  WAP Demo

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Scalable Vector Graphics

• Describing vector graphics data for use over the
  web
• Rendering is done on the browser
• Bandwidth demands lower, scaling easier
• SVG website
• www.w3.org/Graphics/SVG
• SVG Plug-Ins
• www.adobe.com/svg
• SVG Resources
• www.irt.org/articles/js176 1999 article and good,
  brief tutorial
• planet.svg An Example from Deitel

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Bean ML

• Describing software components such as Java Beans
• Defines how the components are interconnected and
  can be used
• Bean ML Specs and Tools
• www.alphaworks.ibm.com/aw.nsf/techmain/bml
• Bean ML Resources
• www.oasis-open.org/cover/beanML.html
• With Bean ML
• You can mark-up beans using Bean ML
• And invoke different operations on Beans
• Includes BML Scripting Framework

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XBRL

• Extensible Business Reporting Language
• Capturing and representing financial and
  accounting information
• Variety of situations
• e.g. publishing reports, extracting data for
  analysis, regulatory forms etc.
• Initiated under the direction of AICPA
• XBRL website
• www.xbrl.org
• XBRL DTDs and Schemas
• http//www.xbrl.org/Core/2000-07-31/default.htm
• Demos and Tools
• http//www.xbrl.org/Demos/demos.htm
• http//www.xbrl.org/Tools.htm

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News ML

• Designed to be media-independent
• Initiated by International Press
  Telecommunications Council
• Enables tracking of news stories over time
• NewsML website
• www.newsml.org
• NewsML DTD
• http//www.oasis-open.org/cover/newsML.html
• SportsML DTD Derived from NewsML DTD
• http//xml.coverpages.org/sportsML.html

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cXML

• CommerceXML from Ariba plus 40 other companies
• cXML website
• www.cxml.org
• Primary Set of Tools/Implementations to support
  cXML
• http//www.ariba.com/solutions/solutions_overview.
  cfm
• See also Whitepapers link explaining how these
  can be used for
• E-procurement
• E-fulfillment
• And others ..

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xCBL

• xCBL from Microsoft, SAP, Sun
• xCBL website
• www.xcbl.org
• Marketed as XML component library for B2B
  e-commerce
• Available Resources (see internal links)
• DTDs and Schemas
• XDK SOX Parser and an XSLT Engine
• Example Documents

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ebXML

• UN/CEFACT the United Nations body whose mandate
  covers worldwide policy and technical development
  in the area of trade facilitation and electronic
  business.
• www.uncefact.org
• ebXML website
• www.ebxml.org
• Current Endorsements
• http//www.ebxml.org/endorsements.htm
• Still needs buy-in from the larger IS/IT vendors
• Related Effort RosettaNet
• http//www.rosettanet.org/rosettanet/Rooms/Display
  Pages/LayoutInitial
• Business Processes for IT, Component and Chip
  companies

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Conclusion

• Overview
• Syntax and Structure
• The XML Alphabet Soup
• XML as a meta-language

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Resources

• http//www.xml.com/
• http//www.w3.org/xml/
• http//www.w3schools.com/
• http//msdn.microsoft.com/xml/