Re: [xsl] Re: XSL Variable declaration

[Michael Kay <mike@xxxxxxxxxxxx>]

On 14/02/2011 10:48, Vasu Chakkera wrote:
>     There is an interesting stylesheet I came across this morning where
> some developer had declared two Xsl:variables one after the other with
> the same name.
>     <xsl:variable name = "foo">
>    </xsl:variable>
>   <xsl:variable name = "foo">
>    </xsl:variable>
>     Not sure why he did that, but to my surprise, it seems to be valid
> in XSLT2 .. and as my expectations, it failed in XSLT1 saying two
> variables cant have same name within the same scope..
>    Is this right??

Yes, this is permitted in XSLT 2.0 but not 1.0 (I assume you are talking 
about local variables).

It can be quite a handy style of programming, so long as you recognize 
that each xsl:variable is a new variable:

<xsl:variable name="s" select="@something"/>
<xsl:variable name="s" select="substring-before($s, ':')"/>
<xsl:variable name="s" select="substring-after($s, '/')"/>
<xsl:variable name="s" select="concat('(', $s, ')')"/>
<xsl:value-of select="$s"/>

Saves (a) writing deeply nested XPath expressions, and (b) thinking up 
new variable names for intermediate results, or (c) changing variable 
names when an extra computation step is introduced.

But it might confuse some readers, so use with care.

Michael Kay
Saxonica