Using Style Sheets to Publish XML to the Web Alan Houser arh@groupwellesley.com 2000 FrameUsers Conference 1 November 2000
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	Contents Using Style Sheets to Publish XML to the Web Contents The Changing World of Publishing The Changing World of Publishing The Changing World of Publishing The Cusp of a Publishing Revolution How to keep up? Today's answer: XML Content vs. Format Displaying XML Style Sheets for Publishing XML Evolution of HTML Evolution of HTML (2) Cascading Style Sheets Example CSS Advantages of CSS and XML Disadvantages of CSS and XML XML Transformation Language (XSLT) XSLT and the Browser Pre-processing XML with XSLT XSLT Advantages Example XSLT Fragments XPath Example XPath Statements Possible Applications of XSLT XSLT Advantages XSLT Disadvantages XML Myths Next Year's Topics
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	The Changing World of Publishing The Early Days
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	The Changing World of Publishing Enter Online Help
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	The Changing World of Publishing The Brave New World
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	The Cusp of a Publishing Revolution   print-on-demand   new output devices (including voice and audio)   customized content   database integration   document-based applications
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	How to keep up?   Single-source solutions   Conditional text   Write for each publishing format
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	Today's answer: XML   Extensible Markup Language   information about your content embedded within your content   your documents become databases of content   select, sort, manipulate the right content, for the right audience, for the right display device   convert the content you have to the content you need
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	Content vs. Format The more tightly content and format of a document are inter-twined, the more difficult it is to reuse/repurpose/republish the contents of the document. Examples:   Bitmaps, PDF   proprietary binary file formats   ascii text   HTML   SGML/XML
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	Displaying XML XML is about content, not about format. Your browser knows how to display a <p>, but probably doesn't know what to do with a <partNumber>. Something must tell the browser how to render the contents of your XML documents.
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	Style Sheets for Publishing XML Cascading Style Sheets (CSS) XML Transformation Language (XSLT)
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	Evolution of HTML Early HTML:   simple tag set   "weak" semantic markup Then things got ugly.
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	Evolution of HTML (2) Is this a heading? Maybe. <font color="red" "ptsize"="24" family="serif" face="Times-roman"> Troubleshooting your Acme Widget</font> Is this a heading? Probably. <h1>Troubleshooting your Acme Widget</h1>
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	Cascading Style Sheets   Extend semantic markup capabilities of HTML   Increase control over page design   Simplify "body" HTML, increase ease of maintenance
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	Example CSS Including CSS in XML document: <?xml version="1.0"?> <?xml-stylesheet type="text/css" href="recipecollection.css"?> <recipeCollection> Example CSS fragment: title {display:block; font-family:'Helvetica, sans-serif'; font-weight: bold; font-size:140%; color:#000000; line-height:150%;}
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	Advantages of CSS and XML   Relatively simple   New application of existing technology   Maintains separation of content and format. To change your browser's rendition of an XML document, change your CSS.
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	Disadvantages of CSS and XML Only works with Microsoft Internet Explorer 5.0 or later. Cannot tranform or manipulate content (all or nothing).
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	XML Transformation Language (XSLT) A language for transforming XML documents to other XML documents. Can select, sort, filter, and manipulate the content of an XML document. Can also convert XML to HTML and text.
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	XSLT and the Browser Microsoft Internet Explorer 5.0 or later supports an older version of XSLT.
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	Pre-processing XML with XSLT Don't depend on user's brower to perform transformation. Process XML with XSLT processor, send result HTML to browser. Examples: XT, Saxon, Xalan.
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	XSLT Advantages   Can manipulate, select, or transform the content of XML documents   Provides the full capabilities of XML documents   Can transform and XML document to HTML for display in any browser
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	Example XSLT Fragments Make <partNumber> elements bold: <xsl:template match="partNumber"> <b> <xsl:value-of select="."/> </b> </xsl:template>
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	XPath XML language for specifying sections of XML documents. Provides means for selecting and filtering content of XML documents for publishing.
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	Example XPath Statements <xsl:template match="para[@role='example']"> <xsl:when test="preceding-sibling::slide"> <a href="{concat($slideNum - 1, '.html')}"> <img src="icons/prev.gif" /> </a> </xsl:when>
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	Possible Applications of XSLT   Display only "cookie" recipes from an XML cookbook   Select news headlines for display on a cell phone or PDA display   Convert a document to a voice markup language
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	XSLT Advantages   Separates content and format. To change the display of an XML file, edit the XSLT stylesheet, not the original XML document.   Can create multiple renditions of our XML data by applying different XSLT transformations to an XML document.   Can create HTML rendition of XML content for display in any browser.
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	XSLT Disadvantages   Only supported by MS IE5 or later browsers (with caveat). Transformation is normally done by the Web server.   Provides a powerful, complex language for manipulating XML documents. Learning curve can be steep.
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	XML Myths   XML will replace HTML   Until all browsers can handle XML, using XML doesn't make sense   XML is the answer to all things
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	Next Year's Topics   Print Publishing with XML   Designing XML Schemas for your Documentation Set   Exploiting XML Pointers
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