Re: [xsl] Confused with templates and XPath

[David Carlisle <davidc@xxxxxxxxx>]

> are you sure of that ?

yes:-)


If I run saxon on the example document that you posted, I get:


$ saxon prio.xml prio.xsl
Recoverable error
Ambiguous rule match for /doc[1]/chapter[1]/para[1]
Matches both "//para" on line 8 of file:/c:/tmp/prio.xsl
and "chapter/para" on line 5 of file:/c:/tmp/prio.xsl


   default-para : para1

   default-para : para2


Or if you prefer:


$ saxon -w2 prio.xml prio.xsl
Recoverable error
Ambiguous rule match for /doc[1]/chapter[1]/para[1]
Matches both "//para" on line 8 of file:/c:/tmp/prio.xsl
and "chapter/para" on line 5 of file:/c:/tmp/prio.xsl
Processing terminated because error recovery is disabled
Error
  Ambiguous rule match for /doc[1]/chapter[1]/para[1]
Matches both "//para" on line 8 of file:/c:/tmp/prio.xsl
and "chapter/para" on line 5 of file:/c:/tmp/prio.xsl
Transformation failed: Run-time errors were reported





>  From my point of view, 
>  chapter/para is more specific, so its priority is 0.5
>  and //para is less specific, so its priority is negative.



_You_ can tell that  chapter/para is more specific than //para but
the XSLT default priorities were explictly designed _not_ to require the
system to do detailed analysis on the paths to determine specificity.

the rules are _very_ simple.

If it is a sigle name, such as "para" then it is priority 0
if it is a child or attribute axis followed by a single name
child::para, attribute::para, @para it would also be 0

If its a namespace wildcard such as x:* it's -0.25

If its a node test such as comment() it's 0.25

otherwise it is 0.5

so:

//para has priority 0.5
chapter/para has priority 0.5
para has priority 0

David


-- 
http://www.dcarlisle.demon.co.uk/matthew

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