XSLT remove unwanted elements

Question

I have XML

<getInquiryAboutListReturn xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <inquiryAbouts>
        <inquiryAbout>
            <code>Code</code>
            <nameKk>Something</nameKk>
            <nameRu>Something</nameRu>
            <documents xsi:nil="true"/>
        </inquiryAbout>
    </inquiryAbouts>
</getInquiryAboutListReturn>

And I want to process it with XSLT to copy all XML

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
    <xsl:output indent="yes" />
    <xsl:template match="/">
        <xsl:copy-of select="//getInquiryAboutListReturn/inquiryAbouts"/>
    </xsl:template>
</xsl:stylesheet>

How could I copy all XML without <documents xsi:nil="true"/> or without xsi:nil="true"?

Desired output XML

<getInquiryAboutListReturn xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <inquiryAbouts>
        <inquiryAbout>
            <code>Code</code>
            <nameKk>Something</nameKk>
            <nameRu>Something</nameRu>
        </inquiryAbout>
    </inquiryAbouts>
</getInquiryAboutListReturn>

Answer 1

This simple XSLT:

<?xml version="1.0"?>
<xsl:stylesheet 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  version="1.0">

  <xsl:output omit-xml-declaration="no" indent="yes"/>
  <xsl:strip-space elements="*"/>

  <!-- TEMPLATE #1 -->
  <xsl:template match="node()|@*">
    <xsl:copy>
      <xsl:apply-templates select="node()|@*"/>
    </xsl:copy>
  </xsl:template>

  <!-- TEMPLATE #2 -->
  <xsl:template match="*[@xsi:nil = 'true']" />

</xsl:stylesheet>

...when applied to the OP's source XML:

<?xml version="1.0"?>
<getInquiryAboutListReturn xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <inquiryAbouts>
    <inquiryAbout>
      <code>Code</code>
      <nameKk>Something</nameKk>
      <nameRu>Something</nameRu>
      <documents xsi:nil="true"/>
    </inquiryAbout>
  </inquiryAbouts>
</getInquiryAboutListReturn>

...produces the expected result XML:

<?xml version="1.0"?>
<getInquiryAboutListReturn xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <inquiryAbouts>
    <inquiryAbout>
      <code>Code</code>
      <nameKk>Something</nameKk>
      <nameRu>Something</nameRu>
    </inquiryAbout>
  </inquiryAbouts>
</getInquiryAboutListReturn>

EXPLANATION:

1. The first template -- the Identity Template -- copies all nodes and attributes from the source XML document as-is.
2. The second template, which matches all elements with the specified, namespaced attribute equalling "true", effectively removes those elements.