Announcement

1
Lecture 16
2
the xslvariable element

• The format of the xslvariable element is
• ltxslvariable nameqname selectexpression/gt
• or
• ltxslvariable nameqnamegt
• lt!-- Content template --gt
• lt/xslvariablegt
• or
• ltxslvariable nameqname/gt
• It tells the XSLT processor to
• instantiate the variable with the given name to
  the value of the expression or to the value of
  the template or to the empty string
• Later, the value of the variable can be accessed
  by an expression comprising followed by the
  name
• xslvariables are not mutable

3
Example usage of the xslvariable element

• lt?xml version"1.0"?gt
• ltxsltransform version"1.0" xmlnsxsl"http//www
  .w3.org/1999/XSL/Transform"gt
• ltxsltemplate match"/"gt
• lthtmlgt ltheadgtlttitlegtSecond-hand
  bookslt/titlegtlt/headgt ltbodygt lttable rules"all"gt
• lttheadgtlttrgtltthgtPricelt/thgtltthgtISBNlt/thgtltthgtTitlelt/
  thgtlt/trgtlt/theadgt lttbodygt
• ltxslfor-each select"./stock/secondHandBooks/boo
  k"gt
• ltxslvariable name"thisISBN
  select"./_at_isbn"/gt
• lttrgtlttdgtltxslvalue-of select"price"/gtlt/tdgt
• lttdgt ltxslvalue-of select"thisISBN"/gt
  lt/tdgtlttdgt
• ltxslvalue-of select"/stock/publications/book_at_is
  bnthisISBN/title"/gtlt/tdgtlt/trgt
• lt/xslfor-eachgt
• lt/tbodygt lt/tablegtlt/bodygtlt/htmlgt lt/xsltemplategt
  lt/xsltransformgt

4
The scope of an xslvariable element

• lt?xml version"1.0"?gt
• ltxsltransform version"1.0" xmlnsxsl"http//www
  .w3.org/1999/XSL/Transform"gt
• ltxsltemplate match"/"gt
• lthtmlgt ltheadgtlttitlegtSecond-hand
  bookslt/titlegtlt/headgt ltbodygt lttable rules"all"gt
• lttheadgtlttrgtltthgtPricelt/thgtltthgtISBNlt/thgtltthgtTitlelt/
  thgtlt/trgtlt/theadgt lttbodygt
• ltxslfor-each select"./stock/secondHandBooks/boo
  k"gt
• lttrgt lttdgtltxslvariable name"thisISBN
  select"./_at_isbn"/gt
• ltxslvalue-of select"price"/gtlt/tdgt
• lttdgt ltxslvalue-of selectthisISBN "/gt
  lt/tdgtlttdgt
• ltxslvalue-of select"/stock/publications/book_at_is
  bnthisISBN/title"/gtlt/tdgtlt/trgt
• lt/xslfor-eachgtlt/tbodygt lt/tablegtlt/bodygtlt/htmlgt
  lt/xsltemplategt lt/xsltransformgt
• Scope of an xslvariable is the element within
  which it was declared

5
Another cross-referencing example

• The type of an item refers to the id of a car
  model
• To produce the HTML table, we use an xslvariable
  to remember an items type and search for model
  containing this id in the set of models

6
The XSL stylesheet for previous slide

• lt?xml version"1.0"?gt
• ltxsltransform version"1.0" xmlnsxsl"http//www
  .w3.org/1999/XSL/Transform"gt
• ltxsltemplate match"/"gt
• lthtmlgt ltheadgtlttitlegtSecond-hand
  carslt/titlegtlt/headgt ltbodygt lttable rules"all"gt
• lttheadgtlttrgtltthgtItemlt/thgtltthgtModellt/thgtltthgtEngine
  Sizelt/thgtltthgtPricelt/thgtlt/trgtlt/
• theadgt lttbodygt
• ltxslfor-each select"./stock/cars/item"gt
• ltxslvariable name"thisType" select"./type"/gt
• lttrgt
• lttdgt ltxslvalue-of select"./_at_num"/gt lt/tdgt
• lttdgt ltxslvalue-of select"/stock/models/model_at_id
  thisType/name"/gt lt/tdgt
• lttdgt ltxslvalue-of select"/stock/models/model_at_id
  thisType/engineSize"/gt lt/tdgt
• lttdgt ltxslvalue-of select"./price"/gt lt/tdgt
• lt/trgt
• lt/xslfor-eachgt
• lt/tbodygt lt/tablegtlt/bodygtlt/htmlgt
• lt/xsltemplategt
• lt/xsltransformgt