Robert Hansson wrote:

> I have been taking over a project with thousands of lines of XSLT code that
> I need to change because of performance and readability problems. About the
> performance issues I 
> 
> need someone to tell me which of the following two examples is the best one
> for performance, what's the differences and what to think about.

> Example 1:
> 
> <xsl:element name="div"><xsl:attribute name="id"><xsl:value-of
> select="@id"/></xsl:attribute></xsl:element>
> 
> Example 2:

> <div id="{@id}"></div>

The only reason to use xsl:element and xsl:attribute is if you need to 
create element and attribute names dynamically.  Otherwise, literal 
result syntax is much more readable, and hence maintainable.  For its 
performance, you always have to test with your sources and processors, 
but in this case there would probably be no noticable difference.

Typical performance problems come from multiple evaluations of the same 
quantity (often inadvertant), poorly designed recursive templates, not 
using keys, using "//", evaluating a whole branch when you need only 
evaluate one node, selecting nodes in the predicate of a template match 
attribute rather than in an apply-templates select attribute, and so on.

For maintenance, use lots of variables for clarity.

Xslt questions are best asked on the Mulberry xslt list.

Cheers,

Tom P

-- 
Thomas B. Passin
Explorer's Guide to the Semantic Web (Manning Books)
http://www.manning.com/catalog/view.php?book=passin