Transforming XML Part II

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Transforming XML Part II

• XML Document Transformation with XSLT

John Arnett, MSc Standards Modeller Information
and Statistics Division NHSScotland Tel [phone]
8073 (x2073) mailtoJohn.Arnett_at_isd.csa.scot.nhs.u
k http//isdscotland.org/xml
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Contents

• XML Document Processing
• XSL Stylesheets
• XSLT
• Template Rules
• Processing Instructions
• Summary
• Find Out More

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XML Document Processing

• Transformation and formatting
• XPath used to locate nodes for input
• XSLT used to transform input and generate result
  tree
• XSL-FO used to format output document

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XSL Stylesheets

• The Stylesheet element

ltxslstylesheet version"1.0" xmlnsxsl"http//ww
w.w3.org/1999/XSL/Transform"gt ltxsltemplate
match"/"gt ltxslapply-templates/gt lt/xsltemplat
egt ltxsltemplate match"pattern"gt lt!-- XSLT
processing instructions --gt lt/xsltemplategt lt!--
More template rules... --gt lt/xslstylesheetgt
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XSL Stylesheets

• Template Rules

ltxslstylesheet version"1.0" xmlnsxsl"http//ww
w.w3.org/1999/XSL/Transform"gt ltxsltemplate
match"/"gt ltxslapply-templates/gt lt/xsltemplat
egt ltxsltemplate match"pattern"gt lt!-- XSLT
processing instructions --gt lt/xsltemplategt lt!--
More template declarations... --gt lt/xslstyleshee
tgt
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XSL Stylesheets

• Processing Instructions

ltxslstylesheet version"1.0" xmlnsxsl"http//ww
w.w3.org/1999/XSL/Transform"gt ltxsltemplate
match"/"gt ltxslapply-templates/gt lt/xsltemplat
egt ltxsltemplate match"pattern"gt lt!-- XSLT
processing instructions --gt lt/xsltemplategt lt!--
More template declarations... --gt lt/xslstyleshee
tgt
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XSL Stylesheets
Source Tree
Style sheet
read template
yes
find source nodes
more templates?
no
Result Tree
evaluate processing instructions
Adapted from XSLT Basics slide presentation by
Paul Spencer, alphaXML
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XSLT Template Rules

• Template Rule
• XPath pattern specifies nodes to match
• ltxsltemplate matchAppointment"gt
• lt/xsltemplategt
• Output template contains XSLT processing
  instructions
• ie. for processing input and creating new element
  and attribute nodes

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XSLT Template Rules

• Template rule for creating PatientId element
  from Appointment

ltxsltemplate match"Appointment"gt ltPatientIdgt
ltIdgt ltxslvalue-of select"Patient/_at_upi"/gt lt/
Idgt ltNamegt ltxslvalue-of select"Patient/text
()"/gt lt/Namegt lt/PatientIdgt lt/xsltemplategt
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XSLT Template Rules

• PatientId output from template rule

ltPatientIdgt ltIdgtABC-123-456lt/Idgt ltNamegtJohn
Smithlt/Namegt lt/PatientIdgt
ltPatientIdgt ltIdgtABC-123-456lt/Idgt ltNamegtJohn
Smithlt/Namegt lt/PatientIdgt
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XSLT Template Rules

• Appointment List

ltAppointmentListgt ltAppointment
deptCodeRADIOgt ltAppointment
deptCodePHYSIOgt ltAppointment
deptCodeGMEDgt ltAppointment
deptCodeGMEDgt ltAppointment
deptCodeCMEDgt ltAppointment
deptCodePHYSIOgt ltAppointment
deptCodeCMEDgt lt/AppointmentListgt
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XSLT Template Rules

• Applying Template Rules
• Creating a list of PatientIds

ltxsltemplate match"AppointmentList"gt ltPatientLi
stgt ltxslapply-templates/gt lt/PatientListgt lt/xsl
templategt ltxsltemplate match"Appointment"gt ltPa
tientIdgt ltIdgtltxslvalue-of select"Patient/_at_upi"
/gtlt/Idgt ltNamegtltxslvalue-of select"Patient/text
()"/gtlt/Namegt lt/PatientIdgt lt/xsltemplategt
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XSLT Template Rules

• PatientIds list output

ltPatientListgt - ltPatientIdgt  ltIdgtABC-123-456lt/
Idgt   ltNamegtJohn Smithlt/Namegt  
lt/PatientIdgt ltPatientIdgt ltPatientIdgt
ltPatientIdgt lt/PatientListgt
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XSLT Processing Instructions

• XSLT - rich syntax that enables
• Copying
• Conditional processing
• ltxslif test_at_deptCode PHYSIOgt...
• Iteration and sorting
• ltxslfor-each selectAppointmentgt...
• Application of XPath functions
• ltxslvalue-of select"concat(_at_deptCode,
  generate-id(.))"gt...
• Creation of new nodes

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XSLT Processing Instructions

• XSLT Elements

• xsltext
• xslif
• xslchoose
• xslwhen
• xslotherwise
• xslforeach

• xslstylesheet
• xsloutput
• xsltemplate
• xslapply-templates
• xslvalue-of

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XSLT Processing Instructions

• Copying and conditional processing
• Creating a list of PHYSIO appointments

ltxsltemplate match"AppointmentList"gt ltPhysioApp
ointmentsgt  ltxslapply-templates/gt  
lt/PhysioAppointmentsgt  lt/xsltemplategt
ltxsltemplate match"Appointment"gt ltxslif
test"_at_deptCode 'PHYSIO'"gt  ltxslcopy-of
select"."/gt   lt/xslifgt  lt/xsltemplategt
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XSLT Processing Instructions

• PHYSIO appointments list output

ltPhysioAppointmentsgt - ltAppointment
deptCode"PHYSIO"gt ltPatient
upi"EFG-567-012"gt  ltCliniciangtMark
Boyddlt/Cliniciangt ltSlot attendDate"05-08-200
2"gt  lt/Appointmentgt ltAppointmentdeptCode"
PHYSIO"gt  lt/PhysioAppointmentsgt
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XSLT Processing Instructions

• Iteration and sorting
• Creating an appointments summary table

lttable border"1"gt ... ltxslfor-each
select"Appointment"gt ltxslsort
select"_at_deptCode" order"ascending"/gt lttrgt lt
tdgtltxslvalue-of select"Patient/text()"/gtlt/tdgt
... lt/trgt lt/xslfor-eachgt lt/tablegt
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XSLT Processing Instructions

• Appointments summary table output

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XSLT Processing Instructions

• Creating new nodes
• XSLT instructions

ltxslelement name"MyNewElement"gt ltxslattribute
name"myNewAttribute"gt value lt/xslattributegt
lt/xslelementgt

• XSLT output

ltMyNewElement myNewAttribute"value"/gt
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In Summary

• XSL stylesheets contain one or more XSLT template
  rules
• Template rules specify nodes to match and contain
  XSLT processing instructions
• XSLT has a rich syntax for transforming documents
  into XML and non-XML outputs

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Find Out More

• W3C XSL Transformations (XSLT) v1.0
  Specification
• www.w3.org/TR/xslt
• Getting started with XSLT and XPath by Ken Holman
  (Parts 1, 2 3)
• www.xml.com/pub/a/2000/08/holman/s2_1.html
• ZVON.org - XSLT Tutorial
• www.zvon.org/xxl/XSLTutorial/

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Find Out More

• Robert Ducharmes Transforming XML column
• www.xml.com/pub/q/transformingxml
• TopXML XSLT Stylesheets
• www.topxml.com/xsltstylesheets/default.asp