how to select number of element values randomly in XSLT

Question

I want to select 30% of values randomly from a XML.As Here is 10 values so , i have to select 3 values randomly.

i have a xml.

<xml>
    <value>A</value>
    <value>B</value>
    <value>C</value>
    <value>D</value>
    <value>E</value>
    <value>F</value>
    <value>G</value>
    <value>H</value>
    <value>I</value>
    <value>J</value>
</xml>

I need this value.

<xml>
    <value>E</value>
    <value>I</value>
    <value>J</value>
</xml>

Does this answer your question? http://exslt.org/random/functions/random-sequence/index.html — Pierre François, May 20 '20 at 13:51
Does the used XSLT 1 processor have support for the EXSLT functions? Or which one is it exactly? — Martin Honnen, May 20 '20 at 14:15
@PierreFrançois I think XSLT 1.0 does not support EXSLT, XSLT transformation error occured [Illegal value: random:random-sequence used for QNAME attribute: name — Rudraprasad Pradhan, May 20 '20 at 14:34
@RudraprasadPradhan I asked which XSLT processor, not which version of XSLT. If you don't know, find out: https://stackoverflow.com/a/25245033/3016153 — michael.hor257k, May 20 '20 at 15:33
@RudraprasadPradhan You are wasting time by repeating the answer you have already given, instead of answering the question you were asked - by now it's 3 times, I think. — michael.hor257k, May 20 '20 at 18:12
@michael.hor257k: the OP clearly doesn't understand our question. — Pierre François, May 20 '20 at 18:34
@PierreFrançois I provided a link to the method to get the answer. Not sure what else I can do. — michael.hor257k, May 20 '20 at 18:38
@RudraprasadPradhan: I will try to reformulate the questions everybody is asking you. You have an XML file as input. You want another XML file as output. Which software or which command do you issue at the shell command line to tell the computer that he has to process the first file into the second one? `xsltproc`? A `javascript` program? A PHP program? A browser? — Pierre François, May 20 '20 at 18:38
@PierreFrançois François This is my xslt processor.. Apache Software Foundation1.0 — Rudraprasad Pradhan, Jun 09 '20 at 18:50
@RudraprasadPradhan: I deduce from your answer that you use the XSLT processor `Xalan`, which is from the Apache Fondation and is a XSLT 1.0 processor. You can generate random numbers outside Xalan and then pass these through some parameters to `Xalan` with the option `-p`. If you show a minimal attempt to code something, we can help you. But nobody will be able to help you if you don't give more details. — Pierre François, Jun 10 '20 at 21:05

Martin Honnen · Answer 1 · 2020-05-20T17:28:32.893

0

In a modern XSLT 3 implementation supporting the random-number-generator function you can use e.g. random-number-generator()?permute(/xml/value)[position() = 1 to 3]:

let $xml := <xml>
<value>A</value>
<value>B</value>
<value>C</value>
<value>D</value>
<value>E</value>
<value>F</value>
<value>G</value>
<value>H</value>
<value>I</value>
<value>J</value>
</xml>,
$values := $xml/value,
$length := xs:integer(count($values) * .3)
return random-number-generator()?permute($values)[position() = 1 to $length]

So you need an XSLT 3 processor like Saxon 10 in any edition or Saxon 9 PE or EE or AltovaXML 2017 R3 or later.

In XSLT 1, if you have support for EXSLT's math:random, you can use

<?xml version="1.0" encoding="UTF-8" ?>
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"
  xmlns:math="http://exslt.org/math">

    <xsl:strip-space elements="*"/>
    <xsl:output indent="yes"/>

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

    <xsl:template match="xml">
        <xsl:copy>
            <xsl:apply-templates select="value[position() &lt; 4]"/>
        </xsl:copy>
    </xsl:template>

    <xsl:template match="value">
        <xsl:copy>
          <xsl:variable name="pos" select="floor(math:random() * 10 + 1)"/>
          <xsl:value-of select="../value[$pos]"/>
        </xsl:copy>
    </xsl:template>    

</xsl:transform>

http://xsltransform.net/93Fbify

edited May 20 '20 at 17:28

answered May 20 '20 at 14:52

Martin Honnen

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You do not necessarily need an XSLT 3 processor. There are other ways to generate a random.number. – michael.hor257k May 20 '20 at 15:35
can it be possible at xslt 1.0?' – Rudraprasad Pradhan May 20 '20 at 16:07
Not possible in XSLT 1.0 without some kind of extension functions. – Michael Kay May 20 '20 at 17:43
Thank You @Martin , I don't have support for EXSLT. I want to do via XSLT 1.0 – Rudraprasad Pradhan May 20 '20 at 18:10
@MichaelKay You do not necessarily need an extension function. A seed supplied from outside may suffice. I have seen suggestions to use some metric of the input XML as the seed, but I don't like the odds of that. – michael.hor257k May 20 '20 at 18:11
Okay , Is it possible via xslt 2.0 ? – Rudraprasad Pradhan May 20 '20 at 18:35
Can you please help me to get xslt select between two position .. Like this is xslt select between two numbers. I want same kind of functionality for 2 positions. – Rudraprasad Pradhan May 20 '20 at 18:37

how to select number of element values randomly in XSLT

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