Why is my variable not being read inside brackets in a select statement xsl-CodePudding

I'm not sure why my queryString variable not being read in totalRecords's select statement. What am I missing or doing wrong?

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xsl:output indent="yes" omit-xml-declaration="yes"/>
    <xsl:template match="/">
    
        <xsl:variable name="carMake">
            <xsl:value-of select="//input_payload/carMake"/>
        </xsl:variable>

        
        <xsl:variable name="queryString">Sold='False'</xsl:variable>
  {
    carMake: <xsl:value-of select="$carMake"/>,
   querystring: <xsl:value-of select="$queryString"/>,
   "totalRecords": <xsl:value-of select="count(//responseAfterTransform[$queryString])"/>,
   
   }
    </xsl:template>

</xsl:stylesheet>

CodePudding user response：

XSLT 3 example showing the use of a shadow attribute with a static parameter or of xsl:evaluate to construct a predicate expression from a string:

<root>
  <item>
    <name>item 1</name>
    <category>foo</category>
  </item>
    <item>
    <name>item 2</name>
    <category>bar</category>
  </item>
    <item>
    <name>item 3</name>
    <category>foo</category>
  </item>
    <item>
    <name>item 4</name>
    <category>baz</category>
  </item>
</root>

XSLT

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    exclude-result-prefixes="#all"
    version="3.0">

  <xsl:param name="predicate" static="yes" as="xs:string" select="'category = ''foo'''"/>

  <xsl:template match="/">
    <shadow-attribute-example>
      <xsl:sequence _select="//item[{$predicate}]"/>
    </shadow-attribute-example>
    <evaluate-example>
      <xsl:evaluate xpath="'//item[' || $predicate || ']'" context-item="."/>
    </evaluate-example>
  </xsl:template>
  
  <xsl:output indent="yes"/>
  
</xsl:stylesheet>

https://xsltfiddle.liberty-development.net/jypqQ9e gives e.g.

<?xml version="1.0" encoding="UTF-8"?>
<shadow-attribute-example>
   <item>
      <name>item 1</name>
      <category>foo</category>
   </item>
   <item>
      <name>item 3</name>
      <category>foo</category>
   </item>
</shadow-attribute-example>
<evaluate-example>
   <item>
      <name>item 1</name>
      <category>foo</category>
   </item>
   <item>
      <name>item 3</name>
      <category>foo</category>
   </item>
</evaluate-example>

CodePudding user response：

I've been trying to find an extension to make this possible in v1 or v2 but have not been sucessful

In some XSLT 1.0 processors (e.g. libxslt or Xalan) you can use the EXSLT dyn:evaluate() extension function - for example:

XML

<root>
  <item>
    <name>item 1</name>
    <category>foo</category>
  </item>
    <item>
    <name>item 2</name>
    <category>bar</category>
  </item>
    <item>
    <name>item 3</name>
    <category>foo</category>
  </item>
    <item>
    <name>item 4</name>
    <category>baz</category>
  </item>
</root>

XSLT 1.0 EXSLT

<xsl:stylesheet version="1.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:dyn="http://exslt.org/dynamic"
extension-element-prefixes="dyn">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>

<xsl:param name="predicate">category="foo"</xsl:param>

<xsl:template match="/root">
    <output>
        <xsl:copy-of select="item[dyn:evaluate($predicate)]" />
    </output>   
</xsl:template>

</xsl:stylesheet>

Result

<?xml version="1.0" encoding="UTF-8"?>
<output>
  <item>
    <name>item 1</name>
    <category>foo</category>
  </item>
  <item>
    <name>item 3</name>
    <category>foo</category>
  </item>
</output>

Not sure why you need this at all. In your example, the predicate is a variable hard-coded into the stylesheet, not a parameter that can be supplied dynamically during runtime. In these circumstances, you could simply hard-code the predicate directly into the select expression, without going through a string first.