Generating UUID in XSLT 1.0

Question

In our legacy project we are using libxslt which is based on xslt 1.0 version. Now there is a need to generate UUID using the xslt file so that our output xml file contains the UUID.

As per https://stackoverflow.com/a/8127174/3747770 I am out of luck.

Also as per this https://gist.github.com/azinneera/778f69ae6b0049b5edcd69da70072405 we can generate UUID, but using xslt 2.0.

I am new to xslt, and is there any way to convert the https://gist.github.com/azinneera/778f69ae6b0049b5edcd69da70072405 style sheet from version 2.0 to 1.0 or is there any other way to generate UUID using xslt 1.0?

Answer 1

As I have stated in the comment to your question, if you are using the libxslt processor, you can use the EXSLT math:random() extension function to generate a sequence of random numbers that will eventually form a version 4 UUID.

Here's an implementation example:

XSLT 1.0 + EXSLT

<xsl:stylesheet version="1.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:math="http://exslt.org/math"
xmlns:func="http://exslt.org/functions"
xmlns:my="www.example.com/my"
extension-element-prefixes="func math my">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
<xsl:strip-space elements="*"/>

<func:function name="my:UUID4">
    <!-- https://www.ietf.org/rfc/rfc4122.txt -->
    <func:result>
        <!-- 8 -->
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:text>-</xsl:text>      
        <!-- 4 -->
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <!-- version identifier -->
        <xsl:text>-4</xsl:text>     
        <!-- 3 -->
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:text>-</xsl:text>      
        <!-- 1* -->
        <xsl:value-of select="substring('89ab', floor(4*math:random()) + 1, 1)" />
        <!-- 3 -->
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:text>-</xsl:text>      
        <!-- 12 -->
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" />
        <xsl:value-of select="substring('0123456789abcdef', floor(16*math:random()) + 1, 1)" /> 
    </func:result>
</func:function>

<xsl:template match="/items">
    <output>
        <xsl:for-each select="item">
            <item id="{my:UUID4()}">
                <xsl:value-of select="." />
            </item>
        </xsl:for-each>
    </output>
</xsl:template>

</xsl:stylesheet>

When applied to the following input:

XML

<items>
    <item>1</item>
    <item>2</item>
    <item>3</item>
    <item>4</item>
    <item>6</item>
    <item>7</item>
    <item>8</item>
    <item>9</item>
</items>

I got the following result:

Result 1

<?xml version="1.0" encoding="UTF-8"?>
<output>
  <item id="77587d4c-1ef6-4aaf-9f97-398dee70fa25">1</item>
  <item id="148e4218-c881-41d3-af61-cab4b5d0251f">2</item>
  <item id="3a02b568-3200-46ff-993c-3bea9724d6ce">3</item>
  <item id="28de29bd-39f4-4eed-979a-765c290652a1">4</item>
  <item id="7c767fa7-c0b7-4187-9f86-d3876ec1be8a">6</item>
  <item id="aca2261f-e837-4a2d-a555-0c81b2c7f7a2">7</item>
  <item id="b7ecb7bd-8c3e-475d-ba17-4c62c1c3d90b">8</item>
  <item id="d28f95e8-452c-474f-9c9a-11e09cd948ae">9</item>
</output>

Subsequent runs produced:

Result 2

<?xml version="1.0" encoding="UTF-8"?>
<output>
  <item id="6eb63a8e-599d-450a-8970-a758b73aa121">1</item>
  <item id="86b247bf-81c8-47ce-9375-4a35e44fcde7">2</item>
  <item id="cbc04786-9e90-4331-a9d3-47955c7d5a99">3</item>
  <item id="9f82f8d0-9934-499e-8783-61087ebce2f7">4</item>
  <item id="5b77da5b-f28f-45a7-82f4-a47b6b1aa7b2">6</item>
  <item id="7eab11bc-209f-4100-b4e6-1cc0f73beda0">7</item>
  <item id="7f4151f4-6166-4406-9ee4-e7de325537d0">8</item>
  <item id="2185c4b8-6a74-4b97-93b4-872b2c0e1f5e">9</item>
</output>

Result 3

<?xml version="1.0" encoding="UTF-8"?>
<output>
  <item id="784b9cd0-a77a-4719-ad0b-183a970b6785">1</item>
  <item id="4dbed80b-4c82-4dde-8a0a-8b29471bdbbf">2</item>
  <item id="0297ad52-3070-4b6a-a28b-a9c7c4607027">3</item>
  <item id="8e402219-3fbf-4025-827b-c95ae4e12ea0">4</item>
  <item id="140c8fad-2d93-4b77-b548-5a150f350d81">6</item>
  <item id="5ca365ac-43dd-41fa-9fa7-6237971576aa">7</item>
  <item id="6ac7bb94-88cd-442e-8c3b-933ca3d53fb5">8</item>
  <item id="3cc77134-77ee-4405-bf33-92e6dc7bfdc1">9</item>
</output>

and so on.

Answer 2

There are some solutions based on languages and approaches for version 1.0 XSLTs.

Let sample XML is as below. (Sample XML is retrieved from https://www.cs.utexas.edu/~mitra/csFall2015/cs329/lectures/xml/xslplanes.2.xml.txt)

<?xml version = "1.0" encoding = "utf-8"?>
<planes xmlns="planes_from_cs_utexas_edu">
   <plane>
      <year> 1977 </year>
      <make> Cessna </make>
      <model> Skyhawk </model>
      <color> Light blue and white </color>
   </plane>
   <plane>
      <year> 1975 </year>
      <make> Piper </make>
      <model> Apache </model>
      <color> White </color>
   </plane>   
   <plane>
      <year> 1960 </year>
      <make> Cessna </make>
      <model> Centurian </model>
      <color> Yellow and white </color>
   </plane>
   <plane>
      <year> 1956 </year>
      <make> Piper </make>
      <model> Tripacer </model>
      <color> Blue </color>
   </plane>
</planes>

Since there is C++ need for the question, there is a solution like below.

1. Using Xalan C++ version (Seems suitable for the question)

There is an example code in C++ for this approach in https://xalan.apache.org/old/xalan-c/extensions.html. It simply shows square rooting but it can be converted into creating GUID as for example using CoCreateGuid() method in Windows or using libuuid in Linux environment and it can be returned as XObjectPtr as converting GUID into XalanDOMString.

---

For example if another languages would be used, then the solutions can be as below.

Java/.NET (Below examples are in Java but these approaches also can be applied on any .NET languages)
1. Using Reflexive Extension Functions (Based on Saxon)
Note: This solution applies to Saxon-PE and Saxon-EE only

XSLT can be as below including direct call to Java's UUID class' method.

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:uuid="java:java.util.UUID"
xmlns:ns1="planes_from_cs_utexas_edu" 
exclude-result-prefixes="uuid">
<xsl:output method="xml" version="1.0" encoding="utf-8" indent="yes"/>
<xsl:template match="/ns1:planes">
     <planes>
         <xsl:for-each select = "ns1:plane">
          <plane>
            <year>
                <xsl:value-of select="ns1:year" />
            </year>
            <make>
                <xsl:value-of select="ns1:make" />
            </make>
            <model>
                <xsl:value-of select="ns1:model" />
            </model>
            <color>
                <xsl:value-of select="ns1:color" />
            </color>
            <uuid>
                <xsl:value-of select="uuid:randomUUID()"/>
            </uuid>
       </plane>
       </xsl:for-each>
     </planes>
    </xsl:template>
</xsl:stylesheet>

The output will be:

<?xml version="1.0" encoding="utf-8"?>
<planes xmlns:ns1="planes_from_cs_utexas_edu">
   <plane>
      <year> 1977 </year>
      <make> Cessna </make>
      <model> Skyhawk </model>
      <color> Light blue and white </color>
      <uuid>50ef735f-a1a1-46cb-a638-05966b2c2b78</uuid>
   </plane>
   <plane>
      <year> 1975 </year>
      <make> Piper </make>
      <model> Apache </model>
      <color> White </color>
      <uuid>8e9b5345-445c-4700-8191-08731c44e1e0</uuid>
   </plane>
   <plane>
      <year> 1960 </year>
      <make> Cessna </make>
      <model> Centurian </model>
      <color> Yellow and white </color>
      <uuid>01b01db9-982a-4811-a5b3-efa73a39dacd</uuid>
   </plane>
   <plane>
      <year> 1956 </year>
      <make> Piper </make>
      <model> Tripacer </model>
      <color> Blue </color>
      <uuid>3a2f7ee2-c53c-46b5-903f-39a21990aa75</uuid>
   </plane>
</planes>

2. Using Integrated Extension Functions (Based on Saxon)
Note: This solution applies to all Saxon editions

See http://saxonica.com/html/documentation/extensibility/integratedfunctions/
Also there is an example usage in Saxon-HE Integrated Extension Functions | how and where?

---

C#

1. XSLT Stylesheet Scripting Using msxsl:script (Based on Microsoft processor)

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:ns1="planes_from_cs_utexas_edu" 
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:user="urn:my-scripts"
exclude-result-prefixes="uuid">
<msxsl:script language="C#" implements-prefix="user">  
     <![CDATA[  
     public double uuid()  
     {  
       return Guid.NewGuid().ToString(); 
     }  
      ]]>  
 </msxsl:script> 

<xsl:output method="xml" version="1.0" encoding="utf-8" indent="yes"/>
<xsl:template match="/ns1:planes">
     <planes>
         <xsl:for-each select = "ns1:plane">
          <plane>
            <xsl:copy-of select="node()"/>
            <uuid>
                <xsl:value-of select="user:uuid()"/>
            </uuid>
       </plane>
       </xsl:for-each>
     </planes>
    </xsl:template>
</xsl:stylesheet>

The output will be similar to above sample output.

Reference: https://learn.microsoft.com/en-us/dotnet/standard/data/xml/xslt-stylesheet-scripting-using-msxsl-script