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XML as Content Management. Prepared by the NYS Forum IT Accessibility Committee http://www.nysforum.org/accessibility/resources/curriculum/xml. Presented by Michael B. Short May 11, 2006. 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/resources/curriculum/xml Presented by Michael B. Short May 11, 2006
XML as Content Management • Objective: the learner will state the accessibility advantage of using XML for content management
XML as Content Management • A brief introduction to XML • How XML separates content from presentation • Leveraging XML for accessible web sites
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
XML: an Introduction • Example <book isbn=‘1-8493-9829-0’> <title>Information Security Management</title> <author>Harold F. Tipton</author> <author>Micki Krause</author> <publisher>Auerbach</publisher> <year>2000</year> </book>
XML: an Introduction • Consists of: • Elements (tags) • Attributes (similar to HTML) • Must have: • Root element • (book tag from the previous example)
XML: an Introduction <?xml version="1.0" encoding="iso-8859-1"?> <slide> <title>XML: an Introduction</title> <topic header=“Consists of:”> <bullet text=“Elements (tags)” /> <bullet text=“Attributes (similar to HTML)” /> </topic> <topic header=“Must have:”> <bullet text=“Root element”> <subbullet text=“(book tag from the previous example)”/> </bullet> </topic> </slide>
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
XSLT (Snippet) <xsl:for-each select=“topic”> <p><xsl:value-of select=“header” /></p> <ul> <xsl:for-each select=“bullet"> <li><xsl:value-of select="." /></li> </xsl:for-each> </ul> </xsl:for-each>
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
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
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
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.
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.
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
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
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
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