Re: [xsl] xsl sorting on derived values

[Trevor Nash <tcn at melvaig dot co dot uk>]

On Mon, 16 Sep 2002 15:08:30 +0100, you wrote:

>Hi,
>
>I need to sort a list based on a value derived from a doubly recursive loop.
>It is a table for cumulative time and I current generate the times using a
>template to perform the recursive steps but I need to sort on these for
>display. Does anyone know if this is possible and, if so, how it can be
>done.
>
Hi Mike

Without knowing exactly what your algorithm is, its hard to tell...
but in principle you can sort on anything that you can calculate in an
XPath expression.  There are tricks you can use to get the effect of
conditionals, but recursion is probably out of the question.

There are a number of approaches:
1.  Can you use sum() instead of recursion?
2.  Do the processing in two passes (either separate transforms or
using node-set), so the first calculates the value you want to sort on
(see the identity transform).
3. Use an extension, assuming you do not mind being tied to one
processor (for example, saxon:function does a good job)
4. Use XSLT 2.0 / XPath 2.0 (currently that means Saxon 7.2).  XPath
2.0 has more facilities which might be enough to implement your time
calculation purely in XPath.

HTH

Trevor Nash
--
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