I'm trying to get the unique values of a custom generated sequence of strings in XSLT. The problem at hand is rather unusual since I have to first split a string on '.' and chop of the last bit, that's working fine but getting the unique values using the XSLT 2.0 distinct-values is not.
Given some input
<TreeNumberList>
<TreeNumber>A01.001.001</TreeNumber>
<TreeNumber>A01.001.002</TreeNumber>
<TreeNumber>A01.001.003</TreeNumber>
<TreeNumber>A01.002.111</TreeNumber>
</TreeNumberList>
The desired output would be an iterable sequence of
A01.001, A01.002
So far I have the following function
<xsl:function name="func:strip-last">
<xsl:param name="str"></xsl:param>
<xsl:value-of select="substring($str, 1, string-length($str) - 1)"></xsl:value-of>
</xsl:function>
<xsl:function name="func:parent-of">
<xsl:param name="nodes"></xsl:param>
<xsl:variable name="output">
<xsl:for-each select="$nodes">
<xsl:variable name="parent">
<xsl:for-each select="tokenize(., '\.')">
<xsl:if test="position() != last()">
<xsl:value-of select="."></xsl:value-of>
<xsl:text>.</xsl:text>
</xsl:if>
</xsl:for-each>
</xsl:variable>
<tmp><xsl:value-of select="func:strip-last($parent))"></xsl:value-of></tmp>
</xsl:for-each>
</xsl:variable>
<xsl:sequence select="distinct-values($output/*)"></xsl:sequence>
</xsl:function>
But this does not return a set of distinct elements, rather a sequence of all the elements involved. The eventual code will be a bit more contrived since the TreeNumbers themselves will not be unique but a some name retrieved through a key lookup will be. (For those recognizing the mark-up, it's part of the MeSH XML)
I've also tried to use a key-ed index or group-by for uniqueness but those did not play well with the document fragments.
Do you have to have functions? Could you just create a variable that has the sequence?
Example...
XML Input
<TreeNumberList>
<TreeNumber>A01.001.001</TreeNumber>
<TreeNumber>A01.001.002</TreeNumber>
<TreeNumber>A01.001.003</TreeNumber>
<TreeNumber>A01.002.111</TreeNumber>
</TreeNumberList>
XSLT 2.0
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:variable name="vAllTreeNumbers">
<xsl:for-each select="/*/TreeNumber">
<xsl:analyze-string select="." regex="(.*)\.[^.]*$">
<xsl:matching-substring>
<xsl:value-of select="concat(regex-group(1),' ')"/>
</xsl:matching-substring>
</xsl:analyze-string>
</xsl:for-each>
</xsl:variable>
<xsl:variable name="vUniqueTreeNumbers" select="distinct-values(tokenize(normalize-space($vAllTreeNumbers),' '))"/>
<xsl:template match="/">
<results>
<!--This demonstrates that each value is part of a sequence.-->
<xsl:for-each select="$vUniqueTreeNumbers">
<item>
<xsl:value-of select="."/>
</item>
</xsl:for-each>
</results>
</xsl:template>
</xsl:stylesheet>
XML Output (just to demonstrate the sequence)
<results>
<item>A01.001</item>
<item>A01.002</item>
</results>
Here's another option that returns the same results...
XSLT 2.0
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:local="local"
xmlns:xs="http://www.w3.org/2001/XMLSchema" exclude-result-prefixes="#all">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:function name="local:getUniqueTreeNumbers">
<xsl:param name="pNodes"/>
<xsl:variable name="vAllTreeNumbers">
<xsl:for-each select="$pNodes">
<xsl:analyze-string select="." regex="(.*)\.[^.]*$">
<xsl:matching-substring>
<xsl:value-of select="concat(regex-group(1),' ')"/>
</xsl:matching-substring>
</xsl:analyze-string>
</xsl:for-each>
</xsl:variable>
<xsl:sequence select="distinct-values(tokenize(normalize-space($vAllTreeNumbers),' '))"></xsl:sequence>
</xsl:function>
<xsl:template match="/">
<results>
<!--This demonstrates that each value is part of an iterable sequence.-->
<xsl:for-each select="local:getUniqueTreeNumbers(*/TreeNumber)">
<item>
<xsl:value-of select="."/>
</item>
</xsl:for-each>
</results>
</xsl:template>
</xsl:stylesheet>
以下表达式将一组不同的值作为字符串序列给出:
distinct-values(TreeNumber/replace(., '\..*$', ''))
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