XML Techie Tools

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XML Techie Tools

• Tim Bornholt

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XML Parsers

• Many types of XML Parsers are available today to
  meet specific business needs.
• Generic parsers
• SAX and DOM
• Data Binding

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SAX and DOM

• Streaming Api for Xml
• Very fast
• One and only one linear pass through the doc
• Uses callback methods to handle events
• DOM
• Flexible can walk the tree up and down
• Memory intensive
• Method calls like getParent(), getChildNodes()

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Data Binding Toolkits

• Take XML Schemas or XML instances and parse into
  objects used by the language.
• Usually create arrays for recurring nodes.
• Objects and method names match the tag names.
• getSchool()
• addAddress()

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Common Uses of XSL

• Two main scenarios for using XSL transformations
• Data conversion
• Publishing

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Data Conversion Applications

• Data conversion will not go away just because XML
  has been invented.
• Different data models
• Different ways of representing things
• Different subsets needed by different people

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Sorting XSL

• Within a ltapply-templatesgt or ltcall-templategt
  block
• ltxslsort select"iPersonalIdentifiers/iSSN"
  data-type"number" order"ascending"/gt
• ltxslsort select"iBirth/iBirthDate"
  data-type"text" order"descending"/gt

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Convert XML to XML

• XSLT is an obvious choice for converting XML from
  one schema to XML in a different schema.
• Convert a COD 2.0c document to COD 2.0d.
• New namespace declaration
• Two new optional fields added

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COD 2.0c to COD 2.0d

• XSL is namespace aware.
• ltxsltemplate match""gt
• ltxslelement name"local-name()"gt
• ltxslcopy-of select"_at_"/gt
• ltxslvalue-of select"text()"/gt
• ltxslapply-templates select""/gt
• lt/xslelementgt
• lt/xsltemplategt

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XML to a Different Format

• May have internal legacy systems without access
  to XML parser.
• XML can be translated into flat file.

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ISIR to Flat File (CSV)

• Tried
• ltxslfor-each select""gt
• ltxslvalue-of select"."/gt
• ltxsltextgt,lt/xsltextgt
• lt/xslfor-eachgt
• Doesnt print anything if tag is missing.
• This doesnt work for csv or fixed length.

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ISIR to Flat File

• Manually pick every column to be displayed.
• ltxslvalue-of select"iLastName"/gt
• ltxsltextgt,lt/xsltextgt
• ltxslvalue-of select"iFirstName"/gt
• ltxsltextgt,lt/xsltextgt
• ltxslvalue-of select"iMiddleInitial"/gt
• ltxsltextgt,lt/xsltextgt

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Different Format to XML

• This can be a bit more cumbersome.
• Implement a SAX interface or a DOM interface that
  parses your file.
• Then treat your alternate format as XML.
• Translate to HTML or PDF with XSLT

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More than One Input Document

• Using the XSLT document() function, additional
  source files can be loaded.

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XSLT Document() Function

• ltxslapply-templates select"document(disb.xml')"
  /gt
• Can insert the whole document or partial based on
  Xpath.
• Different than xslinclude and xslimport.
• Those let you insert one stylesheet in another

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Comparing Two XML Files

• Want to compare published schemas with data
  stored in the registry.
• Pass one file on the command line.
• Load the other file with document().
• For all elements in the first file, find a
  corresponding element in the second.

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Comparing Two XML Files

• ltxslvariable name"elementName" select"_at_name"/gt
• ltxslvalue-of select"elementName"/gt
• ltxslapply-templates select"." mode"xmlverb"/gt
• ltxslvariable name"ad" select"document('registry
  /aid-disbursement.xsd')"/gt
• ltxslapply-templates select"ad//_at_nameelement
  Name" mode"xmlverb"/gt

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Publishing with XSL

• Designed for human consumption.
• Most common uses
• HTML Web pages
• PDF Printable reports

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XML to HTML

• Can be translated several ways
• Transformation handled by the browser
• Transform entire XML document displaying the
  fields necessary
• Convert the document to contain only the fields
  necessary and transform that.

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Translation by the Browser

• Can be accomplished by all modern browsers
• Internet Explorer 4
• Mozilla Firefox 0.9, 1.0
• Opera 6.0
• However!!! Slightly different syntax for
  different browsers and different versions.

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Server Side Translation

• Java Servers can use Servlets or JSPs.
• Requires a minimal amount of code
• Microsoft IIS Servers can use XSL ISAPI extension.

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XML to HTML

• ltxsltemplate match"iCommonRecordISIR"gt
• ltHTMLgt
• ltHEADgtlttitlegtISIR HTML Transformationlt/titlegt
• lt/HEADgt
• ltBODYgt
• ltxslcall-template name"start-table"/gt
• ltxslapply-templates select"iStudent/gt
• ltxslcall-template name"end-table"/gt
• lt/BODYgt
• lt/HTMLgt
• lt/xsltemplategt

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XML to HTML

• Start Table
• ltxsltemplate name"start-table"gt
• ltxsltext disable-output-
• escaping"yes"gtlttable
• border"1"gtlt/xsltextgt
• lttrgtltthgtNamelt/thgtltthgtSSNlt/thgtltthgtBirth
• Datelt/thgtlt/trgt
• lt/xsltemplategt

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XML to HTML

• Outputting data elements
• ltxsltemplate match"iStudent"gt
• lttrgt
• lttdgtltxslapply-templates
• select"iName"/gtlt/tdgt
• lttdgtltxslvalue-of
• select"iPersonalIdentifiers/iSSN"/gtlt/tdgt
• lttdgtltxslvalue-of
• select"iBirth/iBirthDate"/gtlt/tdgt
• lt/trgt
• lt/xsltemplategt

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XML to PDF

• Can use XSL Formatting Objects XSLFO
• Much more control than printing an HTML page
• Able to specify page headers and footers, page
  numbers, footnotes, etc.

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XML to PDF

• Different namespace than XSL
• Many special tags for functionality
• foregion-body
• fostatic-content
• foblock
• fopage-sequence
• foexternal-graphic

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Caveats

• Most all XSLT processors hold the entire XML tree
  in memory.
• Can split XML document into chunks and process
  independently.
• If this isnt practical, XSLT probably isnt a
  good choice for large documents.

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Contact Information
We appreciate your feedback and comments. We can
be reached at
Tim Bornholtz Phone [phone] Email
tim.bornholtz_at_ed.gov
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COD 2.0c to COD 2.0d Demo
All files are provided as samples to demonstrate
the concept only
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ISIR to Flat File Demo
All files are provided as samples to demonstrate
the concept only
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Comparing Two XML Files Demo
All files are provided as samples to demonstrate
the concept only This demo requires XSLT 2
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XML to HTML Demo
All files are provided as samples to demonstrate
the concept only
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XML to PDF Demo
All files are provided as samples to demonstrate
the concept only