XSLT

XSLT stands for Extensible Stylesheet Language Transformations.

Links

Gnome library

exslt (extensions)

http://exslt.org/

Extensions supported in libxml (xsltproc processor)

XPath

https://www.w3.org/TR/xpath/ — Reference specification, which has several xpath examples at the top.

Overview

Currently there are two versions of the XSLT standards: XSLT 1.0 and XSLT 2.0.

XSLT 1.0: On linux, the standard XSLT 1.0 processor is xsltproc (from package xsltproc, libxml2 library).; In XSLT 1.0, most functions come from XSLT extensions (like http://exslt.org/).

XSLT 2.0

On linux, the standard XSLT 2.0 processor is saxonb-xslt (from package libsaxonb-java).
XSLT 2.0 introduces XQuery, XPath 2.0, and XSLT functions (with prefix fn:). See here for a detailed list of features.

Extensions

From w3.org [1]:

The element extension mechanism allows namespaces to be designated as extension namespaces. When a namespace is designated as an extension namespace and an element with a name from that namespace occurs in a template, then the element is treated as an instruction rather than as a literal result element.

Extensions available in the XSLT processor

Using xsltproc (package xsltproc [2], we can get the list of built-in extensions with:

xsltproc --dumpextensions 
# Registered XSLT Extensions
# --------------------------
# Registered Extension Functions:
# {http://exslt.org/math}atan2
# {http://exslt.org/strings}align
# ...

exslt.org/crypto

"Hidden" extensions that provides basic crypto functions (apparently from patch [3], introduced in July 5 2004 [4])
See also [5]
CAUTION — These extensions are not available if using a custom implementation of Python like Anaconda

xsltproc --dumpextensions|grep crypto
# {http://exslt.org/crypto}rc4_decrypt
# {http://exslt.org/crypto}md4
# {http://exslt.org/crypto}sha1
# {http://exslt.org/crypto}md5
# {http://exslt.org/crypto}rc4_encrypt

Example of use:

<xsl:template match="rootnode">
<xsl:value-of select="crypto:md5('ahahah')"/>
</xsl:template>

Quick reference

Minimal stylesheet

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

</xsl:stylesheet>

This is the minimal stylesheet. Another solution is to use an xsl:transform element, which is a synonym to xsl:stylesheet [6].

<?xml version="1.0"?>
<books>
  <book>
    <title>XML in a Nutshell</title>
    <editor>O'Reilly</editor>
  </book>
  <book>
    <title>XSL in a Nutshell</title>
    <editor>O'Reilly</editor>
  </book>
</book>

When applied to the example XML file above (with xsltproc minimal.xsl example.xml), the minimal stylesheet produces this result:

<?xml version="1.0"?>

  
    XML in a Nutshell
    O'Reilly
  
  
    XSL in a Nutshell
    O'Reilly

The result is not empty. This is because by default XSLT has a default template for text node that simply copy the content of the node without transform.

xsl:attribute

Input	Output
<link site="www.stackoverflow.com"/>	<a href="http://www.stackoverflow.com">Click here</a>

Use

<xsl:template match="link">
    <a>
        <xsl:attribute name="href">
            <xsl:text>http://</xsl:text><xsl:value-of select="@site"/>
        </xsl:attribute>
        <xsl:text>Link</xsl:text>
    </a>
</xsl:template>

Or shorter using curly braces {...} [7]:

<xsl:template match="link">
    <a href="http://{@site}">Click here</a>
</xsl:template>

Also for:

Using variables (like in <a href="http://{$varName}">Click here</a>)

func:functions

References:

Using the exslt:func extension, we can define functions in XSLT 1.0.

Here an example stylesheet:

Stylesheet

<?xml version="1.0"?>
<xsl:stylesheet 
    version="1.0" 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:func="http://exslt.org/functions" 
    xmlns:exsl="http://exslt.org/common" 
    xmlns:str="http://exslt.org/strings" 
    xmlns:my="http://myserver.org/xsl/functions"
    extension-element-prefixes="func"
    exclude-result-prefixes="exsl str func my">

    <func:function name="my:dirname">
        <xsl:param name="filename" />
        <func:result>
            <xsl:for-each select="exsl:node-set(str:tokenize($filename,'/'))">
                <xsl:if test="(position()!=1) and (position()!=last())">/</xsl:if>
                <xsl:if test="position()!=last()"><xsl:value-of select="."/></xsl:if>
            </xsl:for-each>
        </func:result>
    </func:function>

    <xsl:template match="file">
        <directory><xsl:value-of select="my:dirname(.)"/></directory>
    </xsl:template>
</xsl:stylesheet>

Input

<?xml version="1.0"?>
<root>
    <file>your/dir/file.ext</file>
    <file>more/directory/with space/dir/file.ext</file>
    <file>file.ext</file>
    <file></file>
</root>

We get the following result (xsltproc style.xsl data.xml):

<?xml version="1.0"?>

    <directory>your/dir</directory>
    <directory>more/directory/with space/dir</directory>
    <directory/>
    <directory/>

Some remarks:

extension-element-prefixes="func" is mandatory, or xsltproc will complain with meaning less errors like:

{http://myserver.org/xsl/functions}dirname: called with too many arguments
xsltApplySequenceConstructor: param was not compiled
xsltApplySequenceConstructor: for-each was not compiled

Types

Boolean

Boolean are constructed with expression false() and true() [8].

<xsl:variable name="var_false" select="false()"/>
<xsl:variable name="var_true" select="true()"/>

which is same as

<xsl:variable name="var_false" select="1 = 0"/>
<xsl:variable name="var_true" select="'true' = 'true'"/>

String

Test for empty

<!-- Test if a string in variable 'var' is empty -->
<xsl:variable name="is_var_empty" select="$var = ''"/>

Use multi-token str:replace

Using node-set:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:exsl="http://exslt.org/common" xmlns:str="http://exslt.org/strings" exclude-result-prefixes="exsl str">

    <xsl:template match="/">
        <xsl:variable name="from"><a>a</a><a>b</a></xsl:variable>
        <xsl:variable name="to"><a>A</a><a>B</a></xsl:variable>
        <xsl:value-of select="str:replace('abcde',exsl:node-set($from)/a,exsl:node-set($to)/a)"/>
    </xsl:template>
</xsl:stylesheet>

This changes the string abcde into ABcde. Note the special construct exsl:node-set($from)/a, where the trailing /a is necessary to tell which elements to use.

Another solution is to use str:split to build a node set in expression context:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:exsl="http://exslt.org/common" xmlns:str="http://exslt.org/strings" exclude-result-prefixes="exsl str">

    <xsl:template match="/">
        <xsl:value-of select="str:replace('abcde',str:split('ab',''),str:split('AB',''))"/>
    </xsl:template>
</xsl:stylesheet>

Tips

Output tags like `<?fileVersion 4.0.0 ?>`

Use a xsl:text tag with attribute disable-output-escaping="yes": [9]:

<xsl:template match="/">
<xsl:text disable-output-escaping="yes">&lt;?fileVersion 4.0.0?&gt;</xsl:text>
</xsl:template>

This will produce:

<?fileVersion 4.0.0?>

Generate a random UID

<xsl:stylesheet
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:data="http://exslt.org/dates-and-times"
    xmlns:math="http://exslt.org/math"
    extension-element-prefixes="date math"
    version='1.0'>
<!-- .... -->
<xsl:variable name="noncels" select="floor(math:random()*800)+100"/>
<xsl:variable name="noncems" select="data:seconds(date:date-time())-date:seconds('1970-01-01T00:00:00')"/>
<!-- .... -->
<xsl:value-of select="concat($noncems,noncels+0)"/>
</xsl:stylesheet>

Beautify / indent an XML file

Use the identity transform: [10]

<?xml version="1.0" encoding="UTF-8" ?>
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
    <xsl:output method="xml"  encoding="UTF-8" indent="yes" />
    <xsl:strip-space elements="*"/>

    <xsl:template match="@*|node()">
        <xsl:copy>
            <xsl:apply-templates select="@*|node()"/>
        </xsl:copy>
    </xsl:template>
</xsl:transform>

Add an attribute to an existing element

We cannot use <copy-of>, which does not allow to modify an element. Instead we must use <copy>, which copies only the element name and namespace, and complete as necessary as in code below [11]:

<xsl:template match="/root/Algemeen/foto/img">
    <xsl:copy>
        <xsl:attribute name="width">100</xsl:attribute>
        <xsl:apply-templates select="@*|node()" />
    </xsl:copy>
</xsl:template>

Use `str:split` or `str:tokenize` to generate node-set in expression context

Using str:split and str:tokenize is an effective way to build a node-set in expression context:

<xsl:template match="/">
    <xsl:value-of select="str:replace('abcde',str:split('abcde',''),str:tokenize('one|two,three/four-five','|,/-'))"/>
</xsl:template>

The example above generates two node-sets to use the multi-token version of str:replace.

Examples

Simple `<xsl:template>`

XSLT file

<?xml version='1.0' encoding="UTF-8"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:param name="PARAM"/>

<xsl:template match="project">
<xsl:text/>This template will replace 'project' by a simple <xsl:value-of select="$PARAM"/><xsl:text/>
</xsl:template>

</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
        <target name="myname"/>
</project>

Processed with: xsltproc -param PARAM "'text'" style.xsl source
output

This template will replace 'project' by a simple text

Spaces and CR

XSLT file

<?xml version='1.0' encoding="UTF-8"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:param name="WORLD"/>

<xsl:template match="project">
    <xsl:text>CR/spaces are preserved...
    inside 'xsl:text'.</xsl:text>

<xsl:text> But spaces/CR between two tags are deleted.</xsl:text>
Except if ...
    it contains non-blanks.
    <xsl:text/>So better use empty text tags<xsl:text/>
    <xsl:text/> to eat spaces/CR, while still using
    ... xslt <xsl:value-of select="$PARAM"/><xsl:text/>
</xsl:template>

</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="myname"/>
</project>

Processed with: xsltproc -param PARAM "'parameters.'" style.xsl source
output

CR/spaces are preserved...
    inside 'xsl:text'. But spaces/CR between two tags are deleted.
Except if ...
    it contains non-blanks.
    So better use empty text tags to eat spaces/CR, while still using
    ... xslt parameters.

Using entities

XSLT file

<?xml version='1.0' encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [
<!ENTITY cr '<xsl:text xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
</xsl:text>'>
<!ENTITY space '<xsl:text xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> </xsl:text>'>
<!ENTITY param '<xsl:value-of xmlns:xsl="http://www.w3.org/1999/XSL/Transform" select="$PARAM"/>'>
<!ENTITY entity '<xsl:value-of xmlns:xsl="http://www.w3.org/1999/XSL/Transform" select="$ENTITY"/>'>
]>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:template match="project">
<xsl:text/>Use entities for special characters like<xsl:text/>
<xsl:text/>&cr;&cr;<xsl:text/>
    carriage return
<xsl:text/>&cr;&cr;<xsl:text/>
<xsl:text/>or "<xsl:text/>&space;&space;&param;&space;&space;<xsl:text/>
<xsl:text/>" where normal "<xsl:text/>
<xsl:text/>  &param;  <xsl:text/>" or
<xsl:text/>

<xsl:text/>carriage return<xsl:text/>

<xsl:text/>
<xsl:text/>
does not work.

Using &entity; is also shorter than using 'xsl:value-of' tags.
</xsl:template>

</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="myname"/>
</project>

Processed with: xsltproc -param PARAM "'space'" -param ENTITY "'entities'" style.xsl source
output

Use entities for special characters like


    carriage return


or "  space  " where normal "space" or
carriage return
does not work.

Using entities is also shorter than using 'xsl:value-of' tags.

Using template parameters

XSLT file

<?xml version='1.0' encoding="UTF-8"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:template match="project">
<xsl:text/>Calling template by matching, passing a string:
<xsl:apply-templates select="target">
	<xsl:with-param name="PARAM" select="'a string'"/>
</xsl:apply-templates>
Calling template by matching, passing a GLOBALPARAM:
<xsl:apply-templates select="target">
	<xsl:with-param name="PARAM" select="$GLOBALPARAM"/>
</xsl:apply-templates>
Calling template by name
<xsl:call-template name="named">
    <xsl:with-param name="PARAM" select="'a string'"/>
</xsl:call-template>
</xsl:template>

<xsl:template match="target">
    <xsl:param name="PARAM"/>
    <xsl:text/>parameter is <xsl:value-of select="$PARAM"/><xsl:text/>
</xsl:template>

<xsl:template name="named">
    <xsl:param name="PARAM"/>
    <xsl:text/>parameter is <xsl:value-of select="$PARAM"/><xsl:text/>
</xsl:template>

</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="myname"/>
</project>

Processed with: xsltproc -param GLOBALPARAM "'global param'" style.xsl source
output

Calling template by matching, passing a string:
parameter is a string
Calling template by matching, passing a GLOBALPARAM:
parameter is global param
Calling template by name
parameter is a string

Simple `<xsl-apply-templates>` and `.`

XSLT file

<?xml version='1.0' encoding="UTF-8"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:template match="project">
<xsl:apply-templates select="target/*"/>
</xsl:template>

<xsl:template match="content">
    <xsl:text/>dot is '<xsl:value-of select="."/>', <xsl:text/>
</xsl:template>

</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="target1">
        <content>content1</content>
        <content>content2</content>
        <content>content3</content>
    </target>
</project>

Processed with: xsltproc style.xsl source
output

dot is 'content1', dot is 'content2', dot is 'content3',

Example of `<xsl:for-each>`

XSLT file

<?xml version='1.0' encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [
<!ENTITY name '<xsl:value-of xmlns:xsl="http://www.w3.org/1999/XSL/Transform" select="@name"/>'>
]>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:template match="project">
<xsl:text/>Simple for-each loop:
    <xsl:for-each select="target/*"><xsl:text/>dot is '<xsl:value-of select="."/>', </xsl:for-each>
For-each loop with select condition:
    <xsl:for-each select="target/content[@id='second']">&name;, </xsl:for-each>
</xsl:template>

</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="target1">
        <content id='first' name="only">content1</content>
        <content id='second' name="double">content2</content>
        <content id='third' name="last">content3</content>
    </target>
</project>

Processed with: xsltproc style.xsl source
output

Simple for-each loop:
    dot is 'content1', dot is 'content2', dot is 'content3', 
For-each loop with select condition:
    double,

Example of `<xsl:choose>`

XSLT file

<?xml version='1.0' encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [
<!ENTITY name '<xsl:value-of xmlns:xsl="http://www.w3.org/1999/XSL/Transform" select="@name"/>'>
]>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:template match="project">
<xsl:apply-templates select="target/*"/>
</xsl:template>

<xsl:template match="target/*">
<xsl:text/><xsl:variable name="TGTTYPE">
    <xsl:choose>
        <xsl:when test="@type='small'">
            <xsl:text/><xsl:value-of select="small"/><xsl:text/>
        </xsl:when>
        <xsl:otherwise>
            <xsl:text/><xsl:value-of select="big"/><xsl:text/>
        </xsl:otherwise>
    </xsl:choose>
</xsl:variable><xsl:text/>
<xsl:text/>We have <xsl:value-of select="$TGTTYPE"/> for <xsl:value-of select="@type"/>.
</xsl:template>


</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="target1">
        <content type='small'><small>content1</small><big>CONTENT1</big></content>
        <content type='big'><small>content2</small><big>CONTENT2</big></content>
        <content type='small'><small>content3</small><big>CONTENT3</big></content>
    </target>
</project>

Processed with: xsltproc style.xsl source
output

We have content1 for small.
We have CONTENT2 for big.
We have content3 for small.

Template with match rule and dynamic entity

XSLT file

<?xml version='1.0' encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [
<!ENTITY name '<xsl:value-of xmlns:xsl="http://www.w3.org/1999/XSL/Transform" select="@name"/>'>
]>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:template match="project/target/*">
    <xsl:value-of select="@type"/>
</xsl:template>


</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="target1">
        <content type='small'><small>content1</small><big>CONTENT1</big></content>
        <content type='big'><small>content2</small><big>CONTENT2</big></content>
        <content type='small'><small>content3</small><big>CONTENT3</big></content>
    </target>
</project>

Processed with: xsltproc style.xsl source
output

    
        small
        big
        small

More complex apply-templates, with dynamic entities

XSLT file

<?xml version='1.0' encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [
<!ENTITY name '<xsl:value-of xmlns:xsl="http://www.w3.org/1999/XSL/Transform" select="@name"/>'>
]>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:template match="project">
    <xsl:apply-templates select="target/*"/>
</xsl:template>

<xsl:template match="project/target/*">
    <xsl:value-of select="@type"/>
</xsl:template>


</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="target1">
        <content type='small'><small>content1</small><big>CONTENT1</big></content>
        <content type='big'><small>content2</small><big>CONTENT2</big></content>
        <content type='small'><small>content3</small><big>CONTENT3</big></content>
    </target>
</project>

Processed with: xsltproc style.xsl source
output

smallbigsmall

Using namespace

XSLT file

<?xml version='1.0' encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [
<!ENTITY name '<xsl:value-of xmlns:xsl="http://www.w3.org/1999/XSL/Transform" select="@name"/>'>
]>

<xsl:stylesheet 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
    xmlns:ns="http://your.server.org/your/xsl/url/MYNS" 
    exclude-result-prefixes="xsl ns"
    version='1.0'>

<xsl:output method="text" indent="no" encoding="UTF-8"/>

<xsl:template match="ns:project">
    <xsl:apply-templates select="ns:target/*"/>
</xsl:template>

<xsl:template match="ns:project/ns:target/*">
    <xsl:if test="@type='small'">SMALL </xsl:if>
    <xsl:if test="@type='big'">BIG </xsl:if>
</xsl:template>


</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<ns:project 
    xmlns:ns="http://your.server.org/your/xsl/url/MYNS" 
    name="myproject">
    <ns:target name="target1">
        <ns:content type='small'>content1</ns:content>
        <ns:content type='big'>content2</ns:content>
        <ns:content type='small'>content3</ns:content>
    </ns:target>
</ns:project>

Processed with: xsltproc style.xsl source
output

SMALL BIG SMALL

Example of expressions

XSLT file

<?xml version='1.0' encoding="UTF-8"?>

<xsl:stylesheet 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:math="http://exslt.org/math"
    extension-element-prefixes="math"
    version='1.0'>

    <xsl:output method="xml" indent="yes" encoding="UTF-8"/>

    <xsl:template match="project">
        <xsl:apply-templates select="target/*"/>
    </xsl:template>

    <xsl:template match="project/target/*">
        <p>
            <msg>dot is current tag content, here '.' is '<xsl:value-of select="."/>'</msg>
            <msg attr="{.}">Use braces {...} in attributes</msg>
            <msg random="unique.{floor(math:random()*2147483647)}">{...} can be any expression</msg>
        </p>
    </xsl:template>
</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="target1">
        <content type='small'>content1</content>
        <content type='big'>content2</content>
        <content type='small'>content3</content>
    </target>
</project>

Processed with: xsltproc style.xsl source
output

<?xml version="1.0" encoding="UTF-8"?>
<p>
  <msg>dot is current tag content, here '.' is 'content1'</msg>
  <msg attr="content1">Use braces {...} in attributes</msg>
  <msg random="unique.799522789">{...} can be any expression</msg>
</p><p>
  <msg>dot is current tag content, here '.' is 'content2'</msg>
  <msg attr="content2">Use braces {...} in attributes</msg>
  <msg random="unique.90206728">{...} can be any expression</msg>
</p><p>
  <msg>dot is current tag content, here '.' is 'content3'</msg>
  <msg attr="content3">Use braces {...} in attributes</msg>
  <msg random="unique.2005052793">{...} can be any expression</msg>
</p>

Generate custom XML tags

XSLT file

<?xml version='1.0' encoding="UTF-8"?>

<xsl:stylesheet 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:math="http://exslt.org/math"
    extension-element-prefixes="math"
    version='1.0'>

    <xsl:output method="xml" indent="yes" encoding="UTF-8"/>

    <xsl:template match="project">
        <xsl:text disable-output-escaping="yes">&lt;?fileVersion 4.0.0?&gt;</xsl:text><cproject id="my project"/>
        <p>Use 'disable-output-escaping' to generate xml tags.</p>
    </xsl:template>
</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target name="target1">
        <content type='small'>content1</content>
        <content type='big'>content2</content>
        <content type='small'>content3</content>
    </target>
</project>

Processed with: xsltproc style.xsl source
output

<?xml version="1.0" encoding="UTF-8"?>
<?fileVersion 4.0.0?><cproject id="my project"/><p>Use 'disable-output-escaping' to generate xml tags.</p>

Removing white spaces

XSLT file

<?xml version='1.0' encoding="UTF-8"?>

<xsl:stylesheet 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    version='1.0'>

    <xsl:output method="xml" indent="yes" version="1.0" encoding="UTF-8" standalone="no"/>

    <xsl:template match="project">
        <project>
            <xsl:apply-templates select="*"/>
        </project>
    </xsl:template>

    <xsl:template match="target">
        <cleaned_target><xsl:value-of select="normalize-space(.)"/></cleaned_target>
    </xsl:template>
</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<project name="myproject">
    <target>no_space_at_all</target>
    <target>   with_space_around  </target>
    <target>with
        carriage
        returns
    </target>
    <target>with  spaces  between  the  words</target>
</project>

Processed with: xsltproc style.xsl source
output

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project>
  <cleaned_target>no_space_at_all</cleaned_target>
  <cleaned_target>with_space_around</cleaned_target>
  <cleaned_target>with carriage returns</cleaned_target>
  <cleaned_target>with spaces between the words</cleaned_target>
</project>

Two-stage xml using variables and node-set

References:

http://www.usingxml.com/Transforms/XslPipelines (see example below)
http://www.xml.com/pub/a/2003/07/16/nodeset.html (very detailed example).

XSLT file

<?xml version='1.0' encoding="UTF-8"?>

<xsl:stylesheet 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:exsl="http://exslt.org/common"
    exclude-result-prefixes="exsl"
    version='1.0'>

    <xsl:variable name="myvar">
        <xsl:apply-templates select="books" mode="stageone"/>
    </xsl:variable>

    <xsl:template match="book" mode="stageone">
        <title><xsl:value-of select="title"/></title>
    </xsl:template>

    <xsl:template match="/">
        <!-- Must use mode="...", or we have recursion since we match "/" -->
        <xsl:apply-templates select="exsl:node-set($myvar)" mode="stagetwo"/>
    </xsl:template>

    <xsl:template match="title" mode="stagetwo">
        <p><xsl:value-of select="."/></p>
    </xsl:template>
</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<books>
  <book>
    <title>XML in a Nutshell</title>
    <editor>O'Reilly</editor>
  </book>
  <book>
    <title>XSL for the Noobs</title>
    <editor>O'Reilly</editor>
  </book>
</books>

Processed with: xsltproc style.xsl source
output

<?xml version="1.0"?>

  <p>XML in a Nutshell</p>
  <p>XSL for the Noobs</p>

Using call-template

XSLT file

<?xml version='1.0' encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version='1.0'>
    <xsl:template match="*">
        <xsl:call-template name="wrap_with_p">
            <xsl:with-param name="content" select="concat('abc','def')"/>
        </xsl:call-template>
    </xsl:template>
    <xsl:template name="wrap_with_p">
        <xsl:param name="content"/>
        <p><xsl:value-of select="$content"/></p>
    </xsl:template>
</xsl:stylesheet>

Source file

<?xml version="1.0"?>
<title>XSL for the Noobs</title>

Processed with: xsltproc style.xsl source
output

<?xml version="1.0"?>
<p>abcdef</p>

Example recursive function

<xsl:template name="escape">
    <xsl:param name="content"/>
    <xsl:if test="string-length($content)>0">
    <xsl:choose>
        <xsl:when test="starts-with($content,'(')"><xsl:text>\(</xsl:text><xsl:call-template name="escapeForMake"><xsl:with-param name="content" select="substring($content, 2)"/></xsl:call-template></xsl:when>
        <xsl:when test="starts-with($content,')')"><xsl:text>\)</xsl:text><xsl:call-template name="escapeForMake"><xsl:with-param name="content" select="substring($content, 2)"/></xsl:call-template></xsl:when>
        <xsl:when test="starts-with($content,'\')"><xsl:text>\\</xsl:text><xsl:call-template name="escapeForMake"><xsl:with-param name="content" select="substring($content, 2)"/></xsl:call-template></xsl:when>
        <xsl:otherwise>
            <xsl:value-of select="substring($content,1,1)"/>
            <xsl:call-template name="escapeForMake">
                <xsl:with-param name="content" select="substring($content, 2)"/>
            </xsl:call-template>
        </xsl:otherwise>
    </xsl:choose>
    </xsl:if>
</xsl:template>

Call it as follow:

<xsl:call-template name="escape"><xsl:with-param name="content"> select="@synopsis" /></xsl:call-template>

Note that the same template could be implemented using string extension:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:func="http://exslt.org/functions" xmlns:exsl="http://exslt.org/common" xmlns:str="http://exslt.org/strings" extension-element-prefixes="func" xmlns:my="http://myserver.org/xsl/functions" exclude-result-prefixes="exsl str func my">

    <func:function name="my:escape">
        <xsl:param name="filename" />
        <func:result>
            <xsl:value-of select="str:replace(str:replace(str:replace($filename,'\','\\'),'(','\('),')','\)')" />
        </func:result>
    </func:function>

    <xsl:template match="file">
        <directory><xsl:value-of select="my:escape()"/></directory>
    </xsl:template>
</xsl:stylesheet>

Or even shorter, using the multi-token version of str:replace:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:func="http://exslt.org/functions" xmlns:exsl="http://exslt.org/common" xmlns:str="http://exslt.org/strings" extension-element-prefixes="func" xmlns:my="http://myserver.org/xsl/functions" exclude-result-prefixes="exsl str func my">

    <func:function name="my:escape">
        <xsl:param name="filename" />
        <func:result>
            <xsl:value-of select="str:replace($filename,str:split('()\',''),str:split('\(,\),\\',','))" />
        </func:result>
    </func:function>

    <xsl:template match="file">
        <directory><xsl:value-of select="my:escape()"/></directory>
    </xsl:template>
</xsl:stylesheet>

Example using node-set to compute sum-products

From http://www.xml.com/pub/a/2003/07/16/nodeset.html:

Stylesheet

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                xmlns:exsl="http://exslt.org/common"
                extension-element-prefixes="exsl"
                version="1.0">

<xsl:template match="/">
  <html>
    <head>
      <title>Invoice</title>
    </head>
    <body>
      <h1>Invoice</h1>
      
      <!-- Format invoice items as a table -->
      <table border="1" style="text-align: center">
        <tr>
          <th>Description</th>
          <th>Quantity</th>
          <th>Unit price</th>
          <th>Subtotal</th>
        </tr>
        <xsl:for-each select="invoice/item">
          <tr>
            <td><xsl:value-of select="description"/></td>
            <td><xsl:value-of select="qty"/></td>
            <td><xsl:value-of select="unitPrice"/></td>
            <td><xsl:value-of select="qty * unitPrice"/></td>
          </tr>
        </xsl:for-each>
        <tr>
          <th colspan="3">Total</th>
          <th>
            <!-- Gather subtotals into variable -->
            <xsl:variable name="subTotals">
              <xsl:for-each select="invoice/item">
                <number>
                  <xsl:value-of select="qty * unitPrice"/>
                </number>
              </xsl:for-each>
            </xsl:variable>

            <!-- Sum subtotals stored as a result tree fragment 
                 in the variable -->
            <xsl:value-of 
              select="sum(exsl:node-set($subTotals)/number)"/>
          </th>
        </tr>
      </table>
    </body>
  </html>
</xsl:template>
  
</xsl:stylesheet>

source

<?xml version="1.0" encoding="utf-8"?>
<invoice>
  <item>
    <description>Pilsner Beer</description>
    <qty>6</qty>
    <unitPrice>1.69</unitPrice>
  </item>
  <item>
    <description>Sausage</description>
    <qty>3</qty>
    <unitPrice>0.59</unitPrice>
  </item>
  <item>
    <description>Portable Barbecue</description>
    <qty>1</qty>
    <unitPrice>23.99</unitPrice>
  </item>
  <item>
    <description>Charcoal</description>
    <qty>2</qty>
    <unitPrice>1.19</unitPrice>
  </item>
</invoice>

In particular, we observe:

We first construct a set of sub-totals with

<xsl:variable name="subTotals"> 
  <xsl:for-each  select="invoice/item">
    <number><xsl:value-of select="qty * unitPrice"/></number>
  </xsl:for-each>
</xsl:variable>

Then we compute the sum with

sum(exsl:node-set($subTotals)/number).

Note the special construct node-set(...)/number, and not simply node-set(...).

Miscellaneous

<xsl:param name="MYPARAM"> in <xsl:stylesheet> node declares a global parameter.

After this declaration we can use $MYPARAM to get the value of the parameter. If it is not declared, we can only use $MYPARAM if it is passed as a parameter (e.g. via command line xsltproc -param MYPARAM "'myparamvalu'"), otherwise an error is triggered.

XSLT

Contents

Links

Overview

Extensions

Extensions available in the XSLT processor

Quick reference

Minimal stylesheet

xsl:attribute

func:functions

Types

Boolean

String

Tips

Output tags like `<?fileVersion 4.0.0 ?>`

Generate a random UID

Beautify / indent an XML file

Add an attribute to an existing element

Use `str:split` or `str:tokenize` to generate node-set in expression context

Examples

Simple `<xsl:template>`

Spaces and CR

Using entities

Using template parameters

Simple `<xsl-apply-templates>` and `.`

Example of `<xsl:for-each>`

Example of `<xsl:choose>`

Template with match rule and dynamic entity

More complex apply-templates, with dynamic entities

Using namespace

Example of expressions

Generate custom XML tags

Removing white spaces

Two-stage xml using variables and node-set

Using call-template

Example recursive function

Example using node-set to compute sum-products

Miscellaneous

Navigation menu

XSLT

Links

Overview

Extensions

Extensions available in the XSLT processor

Quick reference

Minimal stylesheet

xsl:attribute

func:functions

Types

Boolean

String

Tips

Output tags like <?fileVersion 4.0.0 ?>

Generate a random UID

Beautify / indent an XML file

Add an attribute to an existing element

Use str:split or str:tokenize to generate node-set in expression context

Examples

Simple <xsl:template>

Spaces and CR

Using entities

Using template parameters

Simple <xsl-apply-templates> and .

Example of <xsl:for-each>

Example of <xsl:choose>

Template with match rule and dynamic entity

More complex apply-templates, with dynamic entities

Using namespace

Example of expressions

Generate custom XML tags

Removing white spaces

Two-stage xml using variables and node-set

Using call-template

Example recursive function

Example using node-set to compute sum-products

Miscellaneous

Navigation menu

Search

Output tags like `<?fileVersion 4.0.0 ?>`

Use `str:split` or `str:tokenize` to generate node-set in expression context

Simple `<xsl:template>`

Simple `<xsl-apply-templates>` and `.`

Example of `<xsl:for-each>`

Example of `<xsl:choose>`