Opensource web publishing with XML

1
Open-source web publishing with XML

• Edd Dumbill
• edd_at_xml.com
• WWW9 Developers Day 2000

2
Overview

• Editing XML
• tools
• DTDs
• Publishing with XML
• Command line
• Scripting
• Application servers

3
TMTOWTDI

• XML is so flexible, and there are so many tools,
  theres often no right way
• This presentation covers my experiences in
  creating XML-based web sites

4
Editing XML

• You dont use vi?
• text editor validator
• XEmacs / Emacs psgml mode
• http//www.lysator.liu.se/projects/about_psgml.htm
  l
• understands the DTD
• interfaces with command-line parser
• XEmacs ports for Win32 Mac!
• see http//www.xemacs.org/

5
Browsing XML

• See XML.coms comparison at http//xml.com/2000/05
  /03/browserchart/
• Only practical in
• Mozilla (XMLCSS)
• MSIE (XMLMS XSLT)
• For foreseeable future, Web publishing will be in
  (X)HTML

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DTDs

• Roll your own
• DocBook
• XHTML
• You may want to use multiple DTDs

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XML has open source infrastructure

• Expat
• XT
• Apache XML Project
• Xerces
• Xalan
• Cocoon

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Support for XML publishing at all levels

• Command line
• XT, SAXON, make
• Scripting
• PHP, Perl, Python
• Application server
• Zope, Cocoon

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Command line approaches

• XML stored in file system
• XSLT used to generate target HTML
• Make and FTP
• XSLT processors
• XT
• SAXON
• Instant Saxon

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Scripting

• Most scripting environments wrap expat
• PHP, Perl
• Common approach is dynamic XML transformation
• Caching mechanisms required for high volume sites

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PHP

• Wraps expat
• Theres a lot to do for yourself
• sample code http//xmlrpc.usefulinc.com/demo/xmlrp
  c.inc
• switch approach
• A prototype tree library
• http//downloads.dyomedea.com/php3/generic/xml/
• Allows XPath-like manipulation of the XML

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Perl

• Basic approach would be to use XMLParser
• Perl has better XSLT support, XMLXSLT
• Matt Sergeants AxKit handles caching and
  multiple stylesheets
• http//xml.sergeant.org/axkit/

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Application Servers

• Typically provide common services for web sites
  (authentication, sessions, document management)
• Two most common
• Zope
• Apache Group Turbine, Cocoon Jetspeed
• I use the term loosely!

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Apache Cocoon

• XML XSLT engine
• XML -gt DOM -gt-gt DOM -gt HTML
• Cocoon 1 experimental
• Cocoon 2 redesign will be faster
• XML server pages

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Apache Jetspeed

• Built on top of Turbine Cocoon
• Portal server
• Integrates RSS Cocoon applications

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Zope

• Python-based application/web server
• You dont need to be a Python wizard
• Supports drop-in Products
• User others code easily!
• Good and improving XML support
• XMLDocument
• XMLWidget
• DocBook

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Zope XMLDocument

• Zope is based on an object database
• The store knows the structure of an XML document
• So it can be accessed via the DOM, and used
  non-atomically
• Rendering methods can be written via the DOM

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Zope XMLWidgets

• You can think of an XML document as a
  user-interface description
• Each XMLWidget defines behavior for a part of an
  XML document
• Exciting possibilities
• could re-use the idea in other scenarioshttp//ww
  w.xml.org/archives/xml-dev/2000/05/0174.html
• similar to behaviors introduced in CSS3

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Zope DocbookDocument

• A large example of XMLWidgets
• Slow, sadly!
• Ideas collaborative editing of a book online

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Zope RSS

• SiteSummary product
• Publish your RSS
• Import others
• Integrate the content into your site

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Endnotes

• Read XML.com!
• Email me at edd_at_xml.com or post to my weblog
  discussion group http//weblogs.oreillynet.com/ed
  d/
• You can find these slides athttp//usefulinc.com
  /pres/www9/