XSL

1
XSL

• Unit 6
• November 2

2
XSL

• XSL
• eXtensible Stylesheet Language
• Basically a stylesheet for XML documents
• XSL has three parts
• XSLT
• XPath
• XSL-FO

3
XSLT

• The most important bit of XSL
• XSLT allows us to transform an XML document into
  another XML document
• For instance, transform an XML document into an
  XHTML document
• XSLT relies on using XPath
• Were going to use it, but not cover it
• Dont have to go into detail in order to create
  simple, effective XSL documents

4
XSLT Basics

• The whole idea behind XSLT is template matching
• Whats a template?
• Lets say we have a list of students like what
  weve done in class
• ltstudentgt
• ltfirstNamegtMarkylt/firstNamegt
• ltlastNamegtMarklt/lastNamegt
• ltstudentNumbergt2001-22222lt/studentNumbergt
• lt/studentgt

5
Templates, cont.

• We know what one student looks like
• All students follow the same format
• Student
• first name
• last name
• student number
• Every single one of the students in our XML
  document are described in exactly the same manner
• We can use a template to identify and use the
  parts of each student

6
Templates, cont.

• ltstudentListgt
• ltstudentgt
• ltfirstNamegtMarky lt/firstNamegt
• ltlastNamegtMark lt/lastNamegt
• ltstudentNumbergt200122222 lt/lastnamegt
• lt/studentgt
• ltstudentgt
• ltfirstNamegtSelma lt/firstNamegt
• ltlastNamegtBlair lt/lastNamegt
• ltstudentNumbergt200133333 lt/lastnamegt
• lt/studentgt
• lt/studentListgt

7
Creating a New XSL Stylesheet

• Created with a text editor
• Saved with file extension .xsl
• Just like with HTML, we have to put some bits
  at the top of our XSL file
• Again, you do not have to have these memorized
  completely
• I will provide a blank version online when/if
  needed

8
Creating an XSL Stylesheet, cont.

• lt?xml version"1.0" encoding"ISO-8859-1"?gt
• ltxslstylesheet version"1.0" xmlnsxsl"http//ww
  w.w3.org/1999/XSL/Transform"gt
• Or
• lt?xml version"1.0" encoding"ISO-8859-1"?gt
• ltxsltransform version"1.0" xmlnsxsl"http//www
  .w3.org/1999/XSL/Transform"gt
• You can use either xlsstylesheet or
  xlstransform, they are identical

9
Linking the XSL file to the XML file

• The top of our XML file should read something
  like this
• lt?xml version"1.0" encoding"ISO-8859-1"?gt
• lt?xml-stylesheet type"text/xsl"
  hrefstudentlist.xsl"?gt
• This is nearly identical to how we link HTML
  pages to CSS files
• Again, an empty file will be provided for you if
  needed
• But! You do need to know how to link to an XSL
  file

10
xsltemplate

• xsltemplate is an XSL element
• We are going to use it to apply rules when the
  template match is found
• ltxsltemplate match /gt
• match / means that well apply the template
  to the entire XML document
• This is the next line of our XSL file

11
XSL File, so far

• lt?xml version"1.0" encoding"ISO-8859-1"?gt
• ltxslstylesheet version"1.0" xmlnsxsl"http//ww
  w.w3.org/1999/XSL/Transform"gt
• ltxsltemplate match /gt
• .
• lt/xsltemplategt
• lt/xslstylesheetgt

12
Beginning the Transformation to HTML

• What do we need for an html file?
• lthtmlgt
• ltbodygt
• Maybe a ltheadgt tag?
• This is what well add next to our XSL file

13
Beginning HTML

• lt?xml version"1.0" encoding"ISO-8859-1"?gt
• ltxslstylesheet version"1.0" xmlnsxsl"http//ww
  w.w3.org/1999/XSL/Transform"gt
• ltxsltemplate match /gt
• lthtmlgt
• ltheadgtlttitlegtXML Examplelt/titlegtlt/headgt
• ltbodygt
• .
• lt/bodygt
• lt/htmlgt
• lt/xsltemplategt
• lt/xslstylesheetgt

14
In-Class Example

• Adding some HTML

15
How do we add data?

• ltxslvalue-ofgt gives us the value of a certain
  bit of our xml file
• Which bit?
• Well use the select property and the information
  about our tag
• ltxslvalue-of select studentList/student/first_n
  ame/gt
• This long value for select is based on the
  structure of our XML document
• ltstudentListgt is our root element
• ltstudentgt is contained within ltstudentListgt
• ltfirst_namegt is the data were interested in
• Just like paths for URLs

16
In class Example

• Adding some data to our html
• Using more html tags

17
More than Student?

• We can get the data for a single student, but
  what about our list of 3 students?
• Or 300 for that matter?
• We dont want to cut and paste for every student
• What if the number of students changes?
• We can use the ltxslfor-eachgt element to loop
  through each of our students
• Can use it to look through any sets of data
  nodes (think items with () marks)

18
Using ltxslfor-eachgt

• ltxslfor-eachgt requires the use of the select
  attribute
• ltxslfor-each select some expressiongt
• But what to use?
• Depends on the repeat of the data
• In the case of having a list of students
• select studentList/student
• Basically you can read this as for each student,
  apply these rules below
• ltxslfor-each selectstudentList/studentgt

19
In Class Example

• Adding for-each to loop through the students in
  the XML document
• Reversing last and first name
• Changing the format of the data

20
Sorting the Data

• We can sort the data in our XML files
• For instance, we can alphabetize our student list
• Even if its not alphabetical in the XML file,
  the HTML output will have the items in
  alphabetical order
• We are going to use the element
• ltxslsortgt

21
Using ltxslsortgt

• We can specify what we are sorting on
• First name?
• Last name?
• ltxslsort selectlast_namegt
• Default is to sort ascending (A, BZ)
• But we can reverse it by using the order
  property
• ltxslsort selectlast_name orderdescending/gt

22
In Class Example

• Sorting the student list ascending and descending
• Using both first and last name
• Another XML file with products

23
Questions?