Re: [xsl] A sequence of more than one item is not allowed as the value of item

Subject: Re: [xsl] A sequence of more than one item is not allowed as the value of item
From: David Carlisle <davidc@xxxxxxxxx>
Date: Thu, 2 Jun 2005 12:36:22 +0100
   In summary then, when building a string in a variable and you want to
   avoid document node creation it's preferable to use item()+ than
   xs:string+ as that allows the merging of adjacent text nodes before
   atomization, creating a sequence of one item therefore bypassing the
   separator issue?

well yes or no.


If you want to build a (sequence of) string(s) in a variable
then you have to use xs:string+ as otherwise you will get other things
in your sequence (like nodes). Sometimes you don't need to worry about
the difference between a string and a text node, but somethimes you do
(as you've demonstrated). In general the distinction is far more
important in 2.0 than 1.0.

So, if you want a sequence of strings use xsd:string and use
separator="" on a value-of if you don't want the spaces.

If you want a sequence of nodes and/or strings use item()+
(but personally if I knew there was a possibility of adding an unwanted
space I'd just always add separator="" rather than run through the six
point simple content construct in my head every time to see if the
spaces wouldn't be added)

If you just want to use the thing as a string, and don't want spaces,
and don't want to worry about any of this stuff then just use the xsl
1.0 version without an as attribute at all. there is the extra overhead
that you are generating a document node, but since you are also
generating new nodes in the as="item()+" version then this probably
isn't really so expensive (unless Michael says otherwise:-)

David

   <xsl:variable name="foo" as="item()+">
     <xsl:text>abc</xsl:text><xsl:value-of select="'def'"/>
   </xsl:variable>

   <xsl:template match="/">
     <xsl:value-of select="$foo"/>
   </xsl:template>

   Gives the required 'abcdef'

   <xsl:variable name="foo" as="xs:string+">
     <xsl:text>abc</xsl:text><xsl:value-of select="'def'"/>
   </xsl:variable>

   <xsl:template match="/">
     <xsl:value-of select="$foo"/>
   </xsl:template>

   Gives the unwanted 'abc def'

   Hmmmmmmm...



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