This document provides an overview of XSL (eXtensible Stylesheet Language), which is used to transform and present XML documents. It discusses that XSL is made up of XSLT for transformations and XSL-FO for formatting. XSLT is a declarative language that describes the results of transforming an XML document rather than the steps. The document also outlines the basic process of applying XSL transformations using a stylesheet to match nodes and templates.

1. CIS-189

2.  XSL stands for Extensible Stylesheet
◦ Stylesheets are used to manage organization and
presentation of data
 Implemented as an XML language
◦ Rules of XML apply
 Made up of
◦ XSL-FO (Formatting Objects)
◦ XSLT (Transformations)

3.  XSL-FO focused on presentation to screen
and paper
◦ Not well-supported by browsers
 XSLT emphasizes re-organization of data
◦ Typically used for presentation but can also be used
for conversion of data storage format
◦ XSLT is a declarative language
 Similar to SQL, describe results not steps

4.  Cascading Style Sheets used to separate
presentation from data
 XSLT used to change – transform – data
◦ Convert an XML document to XHTML
 Can use both together

5. XSL requires several steps
1. XML processor reads document
◦ Creates document tree
2. XSL processor applies rules from stylesheet
◦ Rules applied to document tree
◦ Rules applied by using pattern matching
 Identify nodes to apply rules to
◦ Rules are stored as templates

6.  XSL works by using an Input Tree
◦ Input Tree comes from XML processor
 Process of changing input values is call Tree
Transformation
 Result of transformation is the Result Tree
◦ Result Tree can include
 XML
 HTML (must adhere to XML rules, i.e., XHTML)
 Formatting Objects

7.  Extensible Stylesheet Transformations is
method of changing (transforming) XML
based on rules of a stylesheet
 Xpath allows manipulation of parts of XML
document
◦ Not XML-based
◦ Provides compact references
 Useful in URI’s, attributes
◦ Document must exist as nodes (previously parsed)

8.  Templates are definitions of rules,
organization
 Patterns define values searching for (where to
apply templates)
 Expressions allow use of functions using
nodes as inputs
 When referring to document attributes
preface name with “@”

9.  <xsl:stylesheet> is root element
◦ Uses namespace to define elements, attributes valid
in a stylesheet
 <xsl:template> defines the rules/
transformations to apply
◦ Match attribute specifies pattern to apply rules to
 Functions similar to criteria
 <xsl:apply-templates> applies the rules
defined for a particular element
◦ Select attribute specifies elements to apply to

10.  <xsl:value-of> returns the value of a
specified node, function
◦ Select attribute specifies value source
 <xsl:copy> copies a node to the result tree
without any child nodes or attributes
 <xsl:copy-of> copies a node and
child/attribute nodes
 <xsl:output> controls the result tree
◦ method=“xml|html|text”

11.  <xsl:if> provides a boolean test to determine
processing
 <xsl:choose> offers an IF ... THEN ... ELSE
construct
 <xsl:for-each> allows each node in a group
to be processed
 <xsl:sort> specifies order for a group of
nodes

12.  Match can use
◦ node name
◦ current position (represented by “.”)
◦ relative position (for example, parent = “..”)
 Specifies where the transformation to be
applied