1. Standards in Information Management: XML
Arijit Sengupta

2. 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

3. Agenda Overview Syntax and Structure The XML Alphabet Soup
XML as a meta-language

4. Overview What 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

5. Overview What is XML? XML is a “use everywhere” data specification
Application X
XML
Documents
Configuration
XML
XML
Repository
Database

6. Overview Documents 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

7. Overview XML and Structured Data
Pre-XML representation of data:
XML representation of the same data:
“PO-1234”,”CUST001”,”X9876”,”5”,”14.98”
<PURCHASE_ORDER>
<PO_NUM> PO-1234 </PO_NUM>
<CUST_ID> CUST001 </CUST_ID>
<ITEM_NUM> X9876 </ITEM_NUM>
<QUANTITY> 5 </QUANTITY>
<PRICE> </PRICE>
</PURCHASE_ORDER>

8. Overview Benefits 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

9. Overview Who Uses XML? Submissions by Technologies using XML Microsoft
IBM
Hewlett-Packard
Fujitsu Laboratories
Sun Microsystems
Netscape (AOL), and others…
Technologies using XML
SOAP, ebXML, BizTalk, WebSphere, many others…

10. Agenda Overview Syntax and Structure The XML Alphabet Soup
XML as a meta-language

11. Syntax and Structure Components of an XML Document
Elements
Each element has a beginning and ending tag
<TAG_NAME>...</TAG_NAME>
Elements can be empty (<TAG_NAME />)
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

12. Syntax and Structure Components of an XML Document
<?xml version=“1.0” ?>
<?xml-stylesheet type="text/xsl” href=“template.xsl"?>
<ROOT>
<ELEMENT1><SUBELEMENT1 /><SUBELEMENT2 /></ELEMENT1>
<ELEMENT2> </ELEMENT2>
<ELEMENT3 type=‘string’> </ELEMENT3>
<ELEMENT4 type=‘integer’ value=‘9.3’> </ELEMENT4>
</ROOT>
Elements with Attributes
Elements
Prologue (processing instructions)

13. Syntax and Structure Rules 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
<tag> and <TAG> are not the same type of element

14. Syntax and Structure Well-Formed XML?
No, CHILD2 and CHILD3 do not nest properly
<xml? Version=“1.0” ?>
<PARENT>
<CHILD1>This is element 1</CHILD1>
<CHILD2><CHILD3>Number 3</CHILD2></CHILD3>
</PARENT>

15. Syntax and Structure Well-Formed XML?
No, there are two root elements
<xml? Version=“1.0” ?>
<PARENT>
<CHILD1>This is element 1</CHILD1>
</PARENT>
<CHILD1>This is another element 1</CHILD1>

16. Syntax and Structure Well-Formed XML?
Yes
<xml? Version=“1.0” ?>
<PARENT>
<CHILD1>This is element 1</CHILD1>
<CHILD2/>
<CHILD3></CHILD3>
</PARENT>

17. Syntax and Structure An XML Document
<?xml version='1.0'?>
<bookstore>
<book genre=‘autobiography’ publicationdate=‘1981’
ISBN=‘ ’>
<title>The Autobiography of Benjamin Franklin</title>
<author>
<first-name>Benjamin</first-name>
<last-name>Franklin</last-name>
</author>
<price>8.99</price>
</book>
<book genre=‘novel’ publicationdate=‘1967’ ISBN=‘ ’>
<title>The Confidence Man</title>
<first-name>Herman</first-name>
<last-name>Melville</last-name>
<price>11.99</price>
</bookstore>

18. Syntax and Structure Namespaces: Overview
Part of XML’s 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
URLs and URNs for namespaces do not have to be “live” – they only need to be unique strings.

19. Syntax and Structure Namespaces: Declaration
Namespace declaration examples:
xmlns: bk = “
xmlns: bk = “urn:mybookstuff.org:bookinfo”
xmlns: bk = “
Namespace declaration
Prefix
URI (URL)

20. Syntax and Structure Namespaces: Examples
<BOOK xmlns:bk=“
<bk:TITLE>All About XML</bk:TITLE>
<bk:AUTHOR>Joe Developer</bk:AUTHOR>
<bk:PRICE currency=‘US Dollar’>19.99</bk:PRICE>
<bk:BOOK xmlns:bk=“ xmlns:money=“urn:finance:money”>
<bk:TITLE>All About XML</bk:TITLE>
<bk:AUTHOR>Joe Developer</bk:AUTHOR>
<bk:PRICE money:currency=‘US Dollar’>
19.99</bk:PRICE>

21. 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:
<BOOK xmlns=“
<TITLE>All About XML</TITLE>
<AUTHOR>Joe Developer</AUTHOR>

22. 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
<BOOK xmlns=“
<TITLE>All About XML</TITLE>
<AUTHOR>Joe Developer</AUTHOR>
<PUBLISHER xmlns=“urn:publishers:publinfo”>
<NAME>Microsoft Press</NAME>
</PUBLISHER>
</BOOK>

23. 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

24. 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.
Entity
Substitution
<
&
&

25. Agenda Overview Syntax and Structure The XML Alphabet Soup
XML as a meta-language

26. The XML ‘Alphabet Soup’
XML itself is fairly simple
Most of the learning curve is knowing about all of the related technologies

27. The XML ‘Alphabet Soup’
Extensible Markup Language
Defines XML documents
Infoset
Information Set
Abstract model of XML data; definition of terms
DTD
Document Type Definition
Non-XML schema
XSD
XML Schema
XML-based schema language
XDR
XML Data Reduced
An earlier XML schema
CSS
Cascading Style Sheets
Allows you to specify styles
XSL
Extensible Stylesheet Language
Language for expressing stylesheets; consists of XSLT and XSL-FO
XSLT
XSL Transformations
Language for transforming XML documents
XSL-FO
XSL Formatting Objects
Language to describe precise layout of text on a page

28. The XML ‘Alphabet Soup’
XPath
XML Path Language
A language for addressing parts of an XML document, designed to be used by both XSLT and XPointer
XPointer
XML Pointer Language
Supports addressing into the internal structures of XML documents
XLink
XML Linking Language
Describes links between XML documents
XQuery
XML Query Language (draft)
Flexible mechanism for querying XML data as if it were a database
DOM
Document Object Model
API to read, create and edit XML documents; creates in-memory object model
SAX
Simple API for XML
API to parse XML documents; event-driven
Data Island
XML data embedded in a HTML page
Data Binding
Automatic population of HTML elements from XML data

29. 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

30. 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

31. The XML ‘Alphabet Soup’ Schemas: DTD Example
XML document:
DTD schema:
<BOOK>
<TITLE>All About XML</TITLE>
<AUTHOR>Joe Developer</AUTHOR>
</BOOK>
<!DOCTYPE BOOK [
<!ELEMENT BOOK (TITLE+, AUTHOR) >
<!ELEMENT TITLE (#PCDATA) >
<!ELEMENT AUTHOR (#PCDATA) >
]>

32. The XML ‘Alphabet Soup’ Schemas: XSD Example
XML document:
<CATALOG>
<BOOK>
<TITLE>All About XML</TITLE>
<AUTHOR>Joe Developer</AUTHOR>
</BOOK> …
</CATALOG>

33. The XML ‘Alphabet Soup’ Schemas: XSD Example
<xsd:schema id="NewDataSet“ targetNamespace="
xmlns="
xmlns:xsd="
xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xsd:element name="book">
<xsd:complexType content="elementOnly">
<xsd:all>
<xsd:element name="title" minOccurs="0" type="xsd:string"/>
<xsd:element name="author" minOccurs="0" type="xsd:string"/>
</xsd:all>
</xsd:complexType>
</xsd:element>
<xsd:element name=“Catalog" msdata:IsDataSet="True">
<xsd:complexType>
<xsd:choice maxOccurs="unbounded">
<xsd:element ref="book"/>
</xsd:choice>
</xsd:schema>

34. 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

35. 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)

36. 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

37. 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.

38. 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 (=, <, and, or, *, +, etc.)

39. The XML ‘Alphabet Soup’ XPath Operators
Usage Description /
Child operator – selects only immediate children (when at the beginning of the pattern, context is root) //
Recursive descent – selects elements at any depth (when at the beginning of the pattern, context is root) .
Indicates current context ..
Selects the parent of the current node *
Wildcard @
Prefix to attribute name (when alone, it is an attribute wildcard)
[ ]
Applies filter pattern

40. 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)
= “textbooks”]
(find all bookstores where the specialty
attribute = “textbooks”) =
(find all books where the style attribute = the
specialty attribute of the bookstore element
at the root)

41. More XPath Examples Path Expression Result /bookstore/book[1]
Selects the first book element that is the child of the bookstore element
/bookstore/book[last()]
Selects the last book element that is the child of the bookstore element
/bookstore/book[last()-1]
Selects the last but one book element that is the child of the bookstore element
/bookstore/book[position()<3]
Selects the first two book elements that are children of the bookstore element
Selects all the title elements that have an attribute named lang
Selects all the title elements that have an attribute named lang with a value of 'eng'
/bookstore/book[price>35.00]
Selects all the book elements of the bookstore element that have a price element with a value greater than 35.00
/bookstore/book[price>35.00]/title
Selects all the title elements of the book elements of the bookstore element that have a price element with a value greater than 35.00

42. XPath Functions Accessor functions: Numeric value 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.

43. The XML ‘Alphabet Soup’ Data Islands
XML embedded in an HTML document
Manipulated via client side script or data binding
<XML id=“XMLID”>
<BOOK>
<TITLE>All About XML</TITLE>
<AUTHOR>Joe Developer</AUTHOR>
</BOOK>
</XML>
<XML id=“XMLID” src=“mydocument.xml”>
Data islands and data binding is available only in Microsoft Internet Explorer version 5.0 and later.

44. The XML ‘Alphabet Soup’ Data Islands
Can be embedded in an HTML SCRIPT element
XML is accessible via the DOM:
<SCRIPT language=“xml” id=“XMLID”>
<SCRIPT type=“text/xml” id=“XMLID”>
<SCRIPT language=“xml” id=“XMLID”
src=“mydocument.xml”>

45. 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))

46. Agenda Overview Syntax and Structure The XML Alphabet Soup
XML as a meta-language

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

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

49. Math ML Describing and manipulating mathematical notations
MathML website
MathML DTD
MathML Browser
MathML Resources
see sample documents here

50. Chemical ML Representing molecular and chemical information
CML website
CML DTD
CML Browser and Authoring Environment
CML Resources
see sample documents here
some require plug-in downloads, can be slow

51. 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
WML DTD
WAP/WML Resources
Tutorial on WML, also see WAP Demo

52. 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
SVG Plug-Ins
SVG Resources
article and good, brief tutorial
planet.svg An Example from Deitel

53. Bean ML Describing software components such as Java Beans
Defines how the components are interconnected and can be used
Bean ML Specs and Tools
Bean ML Resources
With Bean ML
You can mark-up beans using Bean ML
And invoke different operations on Beans
Includes BML Scripting Framework

54. 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
XBRL DTDs and Schemas
Demos and Tools

55. News ML Designed to be media-independent
Initiated by International Press Telecommunications Council
Enables tracking of news stories over time
NewsML website
NewsML DTD
SportsML DTD – Derived from NewsML DTD

56. cXML CommerceXML from Ariba plus 40 other companies cXML website
Primary Set of Tools/Implementations to support cXML
See also Whitepapers link explaining how these can be used for
E-procurement
E-fulfillment
And others ..

57. xCBL xCBL from Microsoft, SAP, Sun xCBL website
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

58. ebXML
UN/CEFACT: the United Nations body whose mandate covers worldwide policy and technical development in the area of trade facilitation and electronic business.
ebXML website
Current Endorsements
Still needs buy-in from the larger IS/IT vendors
Related Effort: RosettaNet
Business Processes for IT, Component and Chip companies

59. Conclusion Overview Syntax and Structure The XML Alphabet Soup
XML as a meta-language

60. Resources http://www.xml.com/ http://www.w3.org/xml/