How do I generate a comma-separated list with XSLT/XPath?
Solution 1
This is a pretty common pattern:
<xsl:for-each select="*">
<xsl:value-of select="."/>
<xsl:if test="position() != last()">
<xsl:text>,</xsl:text>
</xsl:if>
</xsl:for-each>
Solution 2
For an XSLT 2.0 option, you can use the separator
attribute on xsl:value-of
.
This xsl:value-of
:
<xsl:value-of select="/root/item" separator=", "/>
would produce this output:
apple, orange, banana
You could also use more than just a comma for a separator. For example, this:
<xsl:text>'</xsl:text>
<xsl:value-of select="/root/item" separator="', '"/>
<xsl:text>'</xsl:text>
Would produce the following output:
'apple', 'orange', 'banana'
Another XSLT 2.0 option is string-join()
...
<xsl:value-of select="string-join(/*/item,', ')"/>
Solution 3
<xsl:if test="following-sibling::*">,</xsl:if>
or (perhaps more efficient, but you'd have to test):
<xsl:for-each select="*[1]">
<xsl:value-of select="."/>
<xsl:for-each select="following-sibling::*">
<xsl:value-of select="concat(',',.)"/>
</xsl:for-each>
</xsl:for-each>
Solution 4
A simple XPath 1.0 one-liner:
concat(., substring(',', 2 - (position() != last())))
Put it into this transformation:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text"/>
<xsl:template match="/*">
<xsl:for-each select="*">
<xsl:value-of select=
"concat(., substring(',', 2 - (position() != last())))"
/>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
and apply it to the XML document:
<root>
<item>apple</item>
<item>orange</item>
<item>banana</item>
</root>
to get the wanted result:
apple,orange,banana
EDIT:
Here is a comment from Robert Rossney to this answer:
That's pretty opaque code for a human to read. It requires you to know two non-obvious things about XSLT: 1) what the substring function does if its index is out of range and 2) that logical values can be implicitly converted to numerical ones.
and here is my answer:
Guys, never shy from learning something new. In fact this is all Stack Overflow is about, isn't it? :)
Solution 5
Robert gave the classis not(position() = last())
answer. This requires you to process the whole current node list to get context size, and in large input documents this might make the conversion consume more memory. Therefore, I normally invert the test to be the first thing
<xsl:for-each select="*">
<xsl:if test="not(position() = 1)>, </xsl:if>
<xsl:value-of select="."/>
</xsl:for-each>
Anders Sandvig
Updated on November 12, 2020Comments
-
Anders Sandvig over 3 years
Given this XML data:
<root> <item>apple</item> <item>orange</item> <item>banana</item> </root>
I can use this XSLT markup:
... <xsl:for-each select="root/item"> <xsl:value-of select="."/>, </xsl:for-each> ...
to get this result:
apple, orange, banana,
but how do I produce a list where the last comma is not present? I assume it can be done doing something along the lines of:
... <xsl:for-each select="root/item"> <xsl:value-of select="."/> <xsl:if test="...">,</xsl:if> </xsl:for-each> ...
but what should the test expression be?
I need some way to figure out how long the list is and where I currently am in the list, or, alternatively, if I am currently processing the last element in the list (which means I don't care how long it is or what the current position is).