Re: [xsl] questions about preceding::processing-instruction

["Imsieke, Gerrit, le-tex gerrit.imsieke@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

On 10.04.2017 15:12, Erik Zander erik.zander@xxxxxxxxxxxxxxxxxxxx wrote:
> Hi All!
>
> I have an optimization problem concerning 
> preceding::processing-instruction.
>
> First some background in my xml I have processing instructions like 
> <?anchor xml:id="orgPage.7"/?> representing the start of a page.
>
> And I have a template that matches on *text().*
>
> In the template matching on text() I want to know the page number.
>
> To get this I have in the text template declared a variable as
>
> <xsl:variablename="currentPage"select="substring-before(substring-after(((./preceding::processing-instruction('anchor'))[last()]), 
> 'Page.'), '&quot;')"/>
>
> Which works (although I donbt see why as I had the understanding that 
> preceding:: returned in reverse document order) but it takes up a great 
> deal of the processing time.
>
> So my questions are:
>
> Is there a better (faster/smarter) way to get the page from the 
> processing instruction.

Maybe put all of them into a global variable and then do something like 
($all-page-anchors[. &lt;&lt; current()])[last()]

> And is it the expected behavior that calling 
> preceding:processing-instruction() gives me
>
> <?anchor xml:id="orgPage.1"/?>
>
> <?anchor xml:id="orgPage.2"/?>
>
> <?anchor xml:id="orgPage.3"/?>
>
> <?anchor xml:id="orgPage.4"/?>
>
> I have this behavior in both Saxon 9.6.0.7 and Marklogic.

This is because the ( ) around the expression effects that the nodes 
will be put in document order. See the note after 
https://www.w3.org/TR/xpath20/#dt-numeric-predicate

Gerrit

> Regards
>
> Erik Zander
>
> XSL-List info and archive <http://www.mulberrytech.com/xsl/xsl-list>
> EasyUnsubscribe <-list/225679> 
> (by email <>)

--
Gerrit Imsieke
GeschC$ftsfC<hrer / Managing Director
le-tex publishing services GmbH
Weissenfelser Str. 84, 04229 Leipzig, Germany
Phone +49 341 355356 110, Fax +49 341 355356 510
gerrit.imsieke@xxxxxxxxx, http://www.le-tex.de

Registergericht / Commercial Register: Amtsgericht Leipzig
Registernummer / Registration Number: HRB 24930

GeschC$ftsfC<hrer: Gerrit Imsieke, Svea Jelonek,
Thomas Schmidt, Dr. Reinhard VC6ckler