MSc Business Improvement Knowledge Management

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Introduction to XML Part 2
2
Related Standards

• XML documents and DTDs provide foundation for an
  Internet document paradigm do not provide all
  necessary features!
• Need for XML standards (some of which are still
  under development)

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Standard Efforts
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XML Namespaces -

• XML is based on elements, each is distinguished
  by unique element name
• Applications process a document they associate
  element content with corresponding element name
• Naming collisions are problematic for example
  both Accounting and Fullfillment applications use
  term status to signify different meanings
• Using XML Namespaces developers can qualify the
  use of status element in reconciliation document

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XML Namespaces - Example

• ltacctcustomer xmlnsaccthttp//www.foocompany.c
  om/names/acct-REV10gt
• ltacctnamegtBar Corporationlt/acctnamegt
• ltacctaddresseegtAccounts Payable Bar
  Corporationlt/acctaddresseegt
• ltacctorder acctreference5566-1010gt
• ltacctstatusgtinvoicelt/acctstatusgt
• lt/acctordergt
• lt/acctcustomergt
• ltfulcustomer xmlnsfulhttp//www.foocompany.com
  /names/ful-REV10gt
• ltfulnamegtBar Corporationlt/fulnamegt
• ltfuladdresseegtLoading Docklt/fuladdresseegt
• ltfulorder fulreferenceA98755656gt
• ltfulstatusgtshippedlt/fulstatusgt
• lt/fulordergt
• lt/fulcustomergt

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• Namespaces attached to element/attribute with
  colon
• First time use namespace, associate namespace
  prefix with namespace name use reserved XML
  attribute xmlns
• xmlnsacct
• xmlnsful
• Repetition?

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Default Namespace

• ltcustomer xmlnshttp//www.foocompany.com/names/a
  cct-REV10gt
• ltnamegtBar Corporationlt/namegt
• ltaddresseegtAccounts Payable Bar
  Corporationltaddresseegt
• ltorder reference5566-1010gt
• ltstatusgtinvoicelt/statusgt
• lt/ordergt
• lt/customergt
• ltcustomer xmlnshttp//www.foocompany.com/names/f
  ul-REV10gt
• ltnamegtBar Corporationlt/namegt
• ltaddresseegtLoading Docklt/addresseegt
• ltorder referenceA98755656gt
• ltstatusgtshippedlt/statusgt
• lt/ordergt
• lt/customergt

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XML Linking Language - XLink

• Similar to HTML linking but XLink enables people
  to specify links with multiple target documents
  by using XLink namespaces
• Two forms simple and extended

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Simple XLink

• ltBarCorpLink
• xlinkformsimple
• xlinkinlinetrue
• xlinkrefhttp//www.foocompany.com/customers/bar
  corp.xml
• xlinkrolelink record
• xlinktitleBar Corporation
• xlinkshownew
• xlinkactuateuser
• xlinkcontent-rolelink BarCorp record
• xlinkcontent-titleLink to Bar Corporation
  Customer RecordgtBar Corporation
• lt/BarCorpLinkgt

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Extended XLink

• ltBarCorpOrderTrackingLink
• xlinkformextended
• xlinkinlinefalse
• xlinkroletrack order
• xlinkcontent-roletrack BarCorpgt
• ltInvoice
• xlinkformlocator
• xlinkhrefBarCorpInvoice.xml
• xlinktitleBar Corporation Invoice
• xlinkactuateuser/gt
• ltShipment
• xlinkformlocator
• xlinkhrefBarCorpShipment.xml
• xlinktitleBar Corporation Shipment
• xlinkactuateuser/gt
• lt/BarCorpOrderTrackingLinkgt

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Extensible Stylesheet Language - XSL

• Used for formatting document display
• Three primary requirements for solution
• Apply formatting rules to elements
• Usable with different display technologies
• Document consumer may control application of
  stylesheets
• Define formatting templates that apply to an
  element and its subelements
• Select particular elements by using xsl
  namespace
• Instructions for formatting use fo namespace
• Common practice is to use XSL template syntax but
  directly insert HTML tags XSL is used simply as
  transformation language (source doc HTML)

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XSL Example

• ltxsltemplate matchaddress
• ltfoblockgt
• fofont-sizelarge
• fofont-weightbold
• fofont-familyArial
• foline-height2
• ltxslappy-templates/gt
• lt/foblockgt
• lt/xsltemplategt
• ltxsltemplate matchaddress_at_ADDTYPEshipgt
• ltfoblockgt
• fofont-sizesmall
• fofont-weightnormal
• fofont-familyTimesl
• foline-height1
• ltxslappy-templates/gt
• lt/foblockgt
• lt/xsltemplategt

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XSL Transformations - XSLT

• XSLT is used to transform data from one format to
  another
• Used when two companies want to exchange same
  information but apply own internal DTD
• Provides mechanism to support customised data
  flow delivers data to each application in
  format it desires

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XSLT Example

• Ex 1
• ltorder currencyUSDgt
• lt/ordergt
• Ex 2
• ltordergt
• ltcurrencygtUSDlt/currencygt
• lt/ordergt

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XSLT code

• ltxsltemplate match/gt
• ltxslfor-each selectorder
• ltordergt
• ltcurrencygt
• ltxslvalue-of select_at_currency/gt
• lt/currencygt
• lt/ordergt
• lt/xslfor-eachgt
• lt/xsltemplategt

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XML Schema

• Using XML Schema instead of DTDs to specify the
  content of XML documents offers advantages of
  using XML syntax and enforcing datatype
  restrictions on element content and attribute
  values
• Additional features to DTD, such as ability to
  define recurring blocks of elements or attributes
  once and then reuse definition many times

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XML Tools
Applications
Content Management Tools
Authoring Tools
Web Infrastructure
Development Tools
Fundamental Components
Relationship of Major Tools
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Fundamental Components

• Determining factor of XMLs success is
  availability of fundamental software components
  that provide processing documents and related
  standards
• XML parsers typically embedded in applications.
  It reads in physical files associated with a
  document and converts the document text into
  programming constructs accessible to application
  logic
• Tree Based
• Event Based

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Tree-based Parser
XML DTD
Document Tree
Uses App Prog Interface (API)
Tree-Based Parser
Application Logic
Valid
XML Document

• Effective for apps that need random access to doc
  element
• However, building a complete tree for every doc
  is expensive in
• terms of memory
• Event-based parsers avoid this as they do not
  create data structure
• for entire document

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Event-based Parsers
XML DTD
Parsing event
Event-Based Parser
Application Logic
Valid
Data Request
XML Document

• Event-based parsers send parsing events directly
  to application logic
• (beg and end of element but not its attributes)
• If application logic interested in element it
  requests additional data from
• parser
• Effective when application needs only sequential
  access to certain kinds of
• elements

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Web Browsers

• Internet Explorer
• Netscape Navigator
• Modzilla Firefox
• W3C Amaya Web browser derived for testing XML
  documents
• Download for FREE
• http//www.w3c.org/Amaya

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XML Editor

• Windows Notepad or WordPad
• Microsoft XML Notepad
• http//msdn.microsoft.com/xml/notepad/intro.asp
• XML writer available from Wattle Software
• http//www.xmlwriter.com/
• Macintosh Emile editor
• http//www.in-progress.com/emile/

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Special XML characteristics

• Less than symbol (lt) - lt
• Greater than symbol (gt) - gt
• Quote symbol () - quot
• Apostrophe symbol () - apos
• Ampersand symbol () - amp

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Real world XML

• P3P Web privacy policies
• RELML real estate listings
• HRMML human resource infomration (resumes,
  etc.)
• VoxML voice response scripts (Press 1 for this,
  Press 2 for that, etc.)
• VML vector graphics
• SVG vector graphics
• SMIL multimedia presentations
• 3DML three-dimensional virtual worlds

• WML Web pages for mobile devices
• XMLNews news stories
• CDF Web channels
• OSD descriptions of software
• OFX financial information (EFT, etc.)
• RDF descriptions of info in web pages (helps to
  aid search engines)
• MathML mathematical equations

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Application Areas

• Information accessibility and sharing
• Information distribution capabilities
• Document life cycle and content management
• Accumulating knowledge from employees (tacit and
  explicit)
• Searching knowledge repositories, such as
  database systems and the Internet
• Knowledge categorisation systems and limitations
  of classifications
• Workflow systems and integration barriers
• Application integration
• System architecture standardisation and
  compatibility
• Customized publishing
• File configuration and logging
• Electronic commerce