XSL Transformations

brief introduction to XSL transformations

  1. XSL Transformations
    1. Basic Transformation
      1. sample input
      2. sample transform
      3. output
        1. basic example files
    2. Intermediate
      Transformations

      1. sample input
      2. sample transform
      3. output
        1. intermediate
          example files

XSL Transformations

XSLT is a language to transform XML documents into other formats, like
XHTML, XML, Plain Text, (etc.)
XPath is a language for
anvigating XML documents

Basic Transformation

An XSL Transformations is done by one XSLT docuemnt that takes
an XML docuemnt as input. The result of a transformation is a Textual
document. The result can be another XML document, a plain text
document, an XHTML document, or any other kind of textual document.

here is an example

sample input

This sample input describes a list of persons, with its personal
data

<persons>
    <person id="KF14" name="Karl Friederick">
        <address>LudwigStrasse 14, Zurich</address>
    </person>
    <person id="MS12" name="Marc Schiller">
        <address>Rue del la vie 12, Nice</address>
    </person>
</persons>

sample transform

This sample transform produces an HTML document that shows data
in a table

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    version="1.0">
    <xsl:template match="/persons">
        <html>
            <head>
                <title>Persons</title>
            </head>
            <body>
                <h1>Persons</h1>
                <table border="1">
                    <tr>
                        <td>id</td> <td>name</td> <td>address</td>
                    </tr>
                    <xsl:for-each select="person" >
                        <tr>
                            <td><xsl:value-of select="@id"/></td>
                            <td><xsl:value-of select="@name"/></td>
                            <td><xsl:value-of select="address/text()"/></td>
                        </tr>    
                    </xsl:for-each>
                </table>
            </body>
        </html>
    </xsl:template>
</xsl:stylesheet>

output

The transformation output is a webpage that contains XML informations
presented into an HTML webpage.
The webpage looks like the
following image.

basic example files

Here you can download the files of the basic example

Intermediate Transformations

In this transformation we take an XML input document as source,
and we transform it, by hiding some informations and transforming some
others

sample input

We take the sample input seen before, but we put additional
info, like telephone number and email

<persons>
    <person id="KF14" name="Karl Friederick">
        <address>LudwigStrasse 14, Zurich</address>
        <telephone>(41) 444 222 899</telephone>
        <email>c.friederick@dot.com</email>
    </person>
    <person id="MS12" name="Marc Schiller">
        <address>Rue del la vie 12, Nice</address>
        <telephone>(33) 993 212 888</telephone>
        <telephone private="yes">(33) 448 333 717</telephone>
        <email>m.schiller@dot.com</email>
    </person>
</persons>

sample transform

In this transform we make a deep copy of the input, but we
exclude some nodes, and transform some others.

  • we want to hide private telephone
  • we want to transform email address by replacing ‘@‘
    with #
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    version="1.0">
    <xsl:template match="node() | @*">
        <xsl:choose>
            <xsl:when test="local-name()='telephone' and @private='yes'">
                <!-- does nothing -->
            </xsl:when>
            <xsl:when test="local-name()='email'">
                <email>
                    <xsl:value-of select="translate(text(),'@', '#')"/>
                </email>
            </xsl:when>
            <xsl:otherwise>
                <xsl:copy>
                    <xsl:apply-templates select="@* | node()" />
                </xsl:copy>        
            </xsl:otherwise>
        </xsl:choose>    
    </xsl:template>
</xsl:stylesheet>

Note: this solution works with single characters,
since XSLT 1.0 does not provides a
string-replace
function. To replace an entire string you have two ways:

  • use the replace( string, string, string)
    function, with an xslt 2.0 processor
  • write a an XSL 1.0 template that implements an equivalent of
    replace(...) function

output

The output, is the xml document we expect: without
‘private’ telephone, and with ‘@’ character
substituted by ‘#’

<?xml version="1.0" encoding="utf-8"?><persons>
    <person id="KF14" name="Karl Friederick">
        <address>LudwigStrasse 14, Zurich</address>
        <telephone>(41) 444 222 899</telephone>
        <email>c.friederick#dot.com</email>
    </person>
    <person id="MS12" name="Marc Schiller">
        <address>Rue del la vie 12, Nice</address>
        <telephone>(33) 993 212 888</telephone>
        
        <email>m.schiller#dot.com</email>
    </person>
</persons>

intermediate example files

Here you can download the files of the advanced example