Trim Template for XSLT (See related posts)

<xsl:template name="left-trim">
  <xsl:param name="s" />
  <xsl:choose>
    <xsl:when test="substring($s, 1, 1) = ''">
      <xsl:value-of select="$s"/>
    </xsl:when>
    <xsl:when test="normalize-space(substring($s, 1, 1)) = ''">
      <xsl:call-template name="left-trim">
        <xsl:with-param name="s" select="substring($s, 2)" />
      </xsl:call-template>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="$s" />
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

<xsl:template name="right-trim">
  <xsl:param name="s" />
  <xsl:choose>
    <xsl:when test="substring($s, 1, 1) = ''">
      <xsl:value-of select="$s"/>
    </xsl:when>
    <xsl:when test="normalize-space(substring($s, string-length($s))) = ''">
      <xsl:call-template name="right-trim">
        <xsl:with-param name="s" select="substring($s, 1, string-length($s) - 1)" />
      </xsl:call-template>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="$s" />
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

<xsl:template name="trim">
  <xsl:param name="s" />
  <xsl:call-template name="right-trim">
    <xsl:with-param name="s">
      <xsl:call-template name="left-trim">
        <xsl:with-param name="s" select="$s" />
      </xsl:call-template>
    </xsl:with-param>
  </xsl:call-template>
</xsl:template>