xslt-lab/site/content/xslt/functions/xsl-non-matching-substring.md

title, description, date, version, versionLabel, category, syntax, tags

title	description	date	version	versionLabel	category	syntax	tags
xsl:non-matching-substring	Defines the template body applied to each substring that does not match the regex inside xsl:analyze-string.	2026-04-18T00:00:00Z	2.0	XSLT 2.0	element	<xsl:non-matching-substring>	xslt reference xslt2

Description

xsl:non-matching-substring is a child element of xsl:analyze-string. Its body is instantiated once for each portion of the analyzed string that falls between matches — the "gaps" around the matched substrings, including any leading or trailing text.

The element has no attributes. Inside it, the context item (.) is the non-matching segment as a string. regex-group() is not meaningful here because no capture groups apply to unmatched text.

Omitting xsl:non-matching-substring effectively discards all non-matching text from the output, which is useful when you only want to extract the matched parts.

Parameters

xsl:non-matching-substring has no attributes. It contains a sequence constructor.

Return value

The nodes or atomic values produced by the sequence constructor, contributed to the output of the enclosing xsl:analyze-string.

Examples

Extracting only the matched parts (discarding non-matches)

Input XML:

<?xml version="1.0" encoding="UTF-8"?>
<log>Error at line 42: file not found. Warning at line 99: deprecated API.</log>

Stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/log">
    <lines>
      <xsl:analyze-string select="." regex="line \d+">
        <xsl:matching-substring>
          <ref><xsl:value-of select="."/></ref>
        </xsl:matching-substring>
        <!-- No xsl:non-matching-substring: surrounding text is discarded -->
      </xsl:analyze-string>
    </lines>
  </xsl:template>
</xsl:stylesheet>

Output:

<lines>
  <ref>line 42</ref>
  <ref>line 99</ref>
</lines>

Preserving non-matching text alongside highlights

Input XML:

<?xml version="1.0" encoding="UTF-8"?>
<note>Remember to call 555-1234 or 555-5678 if urgent.</note>

Stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="html"/>

  <xsl:template match="/note">
    <p>
      <xsl:analyze-string select="." regex="\d{{3}}-\d{{4}}">
        <xsl:matching-substring>
          <strong><xsl:value-of select="."/></strong>
        </xsl:matching-substring>
        <xsl:non-matching-substring>
          <xsl:value-of select="."/>
        </xsl:non-matching-substring>
      </xsl:analyze-string>
    </p>
  </xsl:template>
</xsl:stylesheet>

Output:

<p>Remember to call <strong>555-1234</strong> or <strong>555-5678</strong> if urgent.</p>

Notes

• xsl:non-matching-substring is only valid as a direct child of xsl:analyze-string.
• If the regex matches the entire string, xsl:non-matching-substring is never instantiated.
• Leading text before the first match and trailing text after the last match are also treated as non-matching substrings.
• The context item is a string; node-related functions like name() or parent:: are not applicable here.

See also

• xsl:analyze-string
• xsl:matching-substring
• regex-group()