Re: [xsl] Clone a Nodeset and then modify some Elements

[Jonas Mellin <jonas.mellin@xxxxxx>]

Alex Maddern wrote, On 2008-09-03 08:48:
> Hi All,
>
> I'm trying to clone a nodeset and alter one or two of the element values in
> an attempt to save me having to rebuild all of them or copy them all over
> and add the new ones.
>
> So What I would like to do is "Copy" SomeBlock named "A" with all the 50+
> child elements intact, but modify one or more random fields with updated
> values 

> [...]
>
> I have played with copying the entire SomeBlock into a Variable, but I'm
> struggling to find a mechanism to updated any of the values without looping
> through all the of the elements and writing them out unless they are the
> Names in question and then writing my own element which just seems lengthy
> to me. Isn't there a way to do something similar to the following:
>
> <xsl:for-each select="/wrapper/actions/action">
>     <xsl:variable name="actionTtype" select="@type">
>     <xsl:variable name="blockName" select="@ref">
>     <xsl:variable name="tempSomeBlock">
>         <xsl:copy-of select="/wrapper/SomeBlock[@name='$blockName']" />
>     </xsl:variable>
>     <xsl:for-each select="field">
>         <!-- Locate the SomeField named @name in $tempSomeBlock and update
> it's value to . of SomeField -->
>     </xsl:for-each>
>     <xsl:copy-of select="tempSomeBlock" />
> </xsl:for-each>
>   
Variables in XSLT are single-assignment so you cannot update the content 
of the variable within the scope it was created. One solution is to 
implement a recursive function that builds the sequence item for item 
for each recursive call and when you reach the and of the input sequence 
you return the resulting sequence back to the top.

BTW, nodeset is a concept from XSLT 1.0, which has been replaced with 
sequences in XSLT 2.0. See www.w3.org for more information. If you are 
using XSLT 1.0, you need to implement the recursive function as a named 
template, whereas in XSLT 2.0 you can implement it as a function.
>  
> As you can see this isn't right and I was looking for a short sharp kick in
> the pants to point me in the right direction.
>
> Caveats - Obviously this is a watered down example which I think covers the
> area I am having trouble with. The values that will replace the existing one
> will come from various sources further down the document, not just within
> the action\field elements
>
> Any help or abuse greatly appreciated
>
> Al
>
>   


--
Carpe Diem!
===
Jonas Mellin, Assistant Professor in Computer Science
School of Humanities and Informatics, Building E-2
University of Skvvde, P.O. Box 408, SE-541 28 Skvvde, Sweden
Phone: +46 500 448321, Fax: +46 500 448399
Email: jonas.mellin@xxxxxx, URL: http://www.his.se/melj