XML as Content Management

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• XML as Content Management

Prepared by the NYS Forum IT Accessibility
Committee http//www.nysforum.org/accessibility/re
sources/curriculum/xml
Presented by Michael B. Short November 17, 2006
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XML as Content Management

• Objective the learner will gain an overview of
  using XML for content management on the web

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XML as Content Management

• A brief introduction to XML
• How XML separates content from presentation
• Leveraging XML for accessible web sites
• Some key issues facing XML developers

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XML an Introduction

• XML
• Extensible Markup Language
• a tag-based language for describing the contents
  of documents
• Two main flavors
• Pre-defined standards
• Self-defined grammars

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XML an Introduction

• Example
• ltbook isbn1-8493-9829-0gt
• lttitlegtInformation Security Managementlt/titlegt
• ltauthorgtHarold F. Tiptonlt/authorgt
• ltauthorgtMicki Krauselt/authorgt
• ltpublishergtAuerbachlt/publishergt
• ltyeargt2000lt/yeargt
• lt/bookgt

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XML an Introduction

• Consists of
• Elements (tags)
• Attributes (similar to HTML)
• Must have
• Root element
• (book tag from the previous example)

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XML an Introduction

• lt?xml version"1.0" encoding"iso-8859-1"?gt
• ltslidegt
• lttitlegtXML an Introductionlt/titlegt
• lttopic headerConsists ofgt
• ltbullet textElements (tags) /gt
• ltbullet textAttributes (similar to HTML) /gt
• lt/topicgt
• lttopic headerMust havegt
• ltbullet textRoot elementgt
• ltsubbullet text(book tag from the
  previous example)/gt
• lt/bulletgt
• lt/topicgt
• lt/slidegt

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XSLT

• Extensible Style sheet Language Translation
• XSL is XML
• Instructions for transforming XML into another
  form
• Could be instructions from rendering a document
  in HTML
• Or perhaps PDF
• Or virtually any other form

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XSLT (Snippet)

• ltxslfor-each selecttopicgt
• ltpgtltxslvalue-of selectheader /gtlt/pgt
• ltulgt
• ltxslfor-each selectbullet"gt
• ltligtltxslvalue-of select"." /gtlt/ligt
• lt/xslfor-eachgt
• lt/ulgt
• lt/xslfor-eachgt

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How XML Solves Accessibility Issues

• One style sheet can be applied to a multitude of
  XML source documents
• More than one style sheet can be applied to the
  same source document

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How XML Solves Accessibility Issues

• One style sheet can be applied to a multitude of
  XML source documents
• The style sheet can be constructed to render
  accessible, standard HTML
• Once the style sheet is correct, any HTML
  document generated using the style sheet will be
  valid, standard and accessible

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XML can Separate Data from HTML

• When HTML is used to display data, the data is
  stored inside your HTML
• With XML, your data is stored outside your HTML

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XML can Separate Data from HTML

• With XML, data can be stored in separate XML
  files
• This way you can concentrate on using HTML for
  data layout and display, and be sure that changes
  in the underlying data will not require any
  changes to your HTML.

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XML can Separate Data from HTML

• XML data can also be stored inside HTML pages as
  "Data Islands".
• You can still concentrate on using HTML only for
  formatting and displaying the data.

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How XML Solves Accessibility Issues

• More than one style sheet can be applied to the
  same source document
• one style sheet to render HTML
• another style sheet to render PDF
• The same source document, guaranteeing the
  same content, can be used to generate more than
  one version for different uses

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How XML Solves Accessibility Issues

• Style sheets can be extended as new situations
  arise
• Declare new tags to manage the new situation
• Update the style sheet portfolio to render the
  new tags
• Handle the situation once for each style sheet
  and all future documents meet the standard

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What happens today

• Modern browsers will perform the translation on
  the fly when the source document and style sheet
  are present
• Older browsers display the source XML
• Thus, you cannot depend on client-side
  translation yet

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Issues with Server-side XML

• XML requires a shift in thinking
• Separation of content and presentation is pretty
  much complete
• Source documents must meet strict formatting
  requirements, requiring more discipline
• Converting large sites requires a large effort