Удаляет пробелы, знаки табуляции и перевода каретки
<xsl:variable name="whitespace" select="'	 '" />
<!-- Strips trailing whitespace characters from 'string' -->
<xsl:template name="string-rtrim">
<xsl:param name="string" />
<xsl:param name="trim" select="$whitespace" />
<xsl:variable name="length" select="string-length($string)" />
<xsl:if test="$length > 0">
<xsl:choose>
<xsl:when test="contains($trim, substring($string, $length, 1))">
<xsl:call-template name="string-rtrim">
<xsl:with-param name="string" select="substring($string, 1, $length - 1)" />
<xsl:with-param name="trim" select="$trim" />
</xsl:call-template>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="$string" />
</xsl:otherwise>
</xsl:choose>
</xsl:if>
</xsl:template>
<!-- Strips leading whitespace characters from 'string' -->
<xsl:template name="string-ltrim">
<xsl:param name="string" />
<xsl:param name="trim" select="$whitespace" />
<xsl:if test="string-length($string) > 0">
<xsl:choose>
<xsl:when test="contains($trim, substring($string, 1, 1))">
<xsl:call-template name="string-ltrim">
<xsl:with-param name="string" select="substring($string, 2)" />
<xsl:with-param name="trim" select="$trim" />
</xsl:call-template>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="$string" />
</xsl:otherwise>
</xsl:choose>
</xsl:if>
</xsl:template>
<!-- Strips leading and trailing whitespace characters from 'string' -->
<xsl:template name="string-trim">
<xsl:param name="string" />
<xsl:param name="trim" select="$whitespace" />
<xsl:call-template name="string-rtrim">
<xsl:with-param name="string">
<xsl:call-template name="string-ltrim">
<xsl:with-param name="string" select="$string" />
<xsl:with-param name="trim" select="$trim" />
</xsl:call-template>
</xsl:with-param>
<xsl:with-param name="trim" select="$trim" />
</xsl:call-template>
</xsl:template>
Вызов:
<xsl:call-template name="string-trim">
<xsl:with-param name="string" select="." />
</xsl:call-template>
Примечание: если требуется удалить только пробелы, разумнее использовать встроенную функцию normalize-space($string)
<xsl:template name="removeMultipleSpaces">
<xsl:param name="string" />
<xsl:value-of select="normalize-space($string)"/>
</xsl:template>
<xsl:call-template name="removeMultipleSpaces">
<xsl:with-param name="string" select="." />
</xsl:call-template>