xsl:for each problem

riffla · March 12th, 2008, 05:14 PM

Hi

Have a problem with a loop of subitems. Having an xml input file containing a <servicelist> item, with several subitems <service>. The
service subitem contains four subelements, which can be seen in code below. But my problem lies in the loop repeating the first <service> item 'n' times, where 'n' corresponds to number of <service> items, which actually means the loop is repeated the right number of times.
The loop should pick the <service> items one by one, since in each round a new item should be the context. Putting position() in the loop gives the right response (1-'n').
Here's code from my xsl:

Code:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet  xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0" xmlns:na="http://www.netadmin.se/2006/API_XMLSchema">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>

<xsl:template match="/">
...
...
...
 <xsl:for-each select="//na:servicelist/na:service">
   <service>
      <service_id>
    <xsl:value-of select="//na:service_id"/>
      </service_id>
      <cpe_type>
    <xsl:value-of select="//na:cpe_type"/>
      </cpe_type>
      <state>
    <xsl:value-of select="//na:state"/>
      </state>
      <free_date>
    <xsl:value-of select="//na:free_date"/>
      </free_date>
   </service>
 </xsl:for-each>
</xsl:template
...
...
...
</xsl:stylesheet>

And here's the xml:

Code:

<?xml version="1.0" encoding="utf-8"?>
<GetAvailableServicesOut xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.netadmin.se/2006/API_XMLSchema" xsi:schemaLocation="http://www.netadmin.se/2006/API_XMLSchema C:\teliasonera\herkules\webServiceAdapter\XSD\GetAvailableServicesOut.xsd">
    <servicelist>
        <service>
            <service_id>4576</service_id>
            <cpe_type>Prod_cpe_type</cpe_type>
            <state>free</state>
            <free_date>2008-03-22</free_date>            
        </service>
        <service>
            <service_id>0123</service_id>
            <cpe_type>Test_cpe_type</cpe_type>
            <state>mod</state>
            <free_date>2008-03-12</free_date>
        </service>
        <service>
            <service_id>999</service_id>
            <cpe_type>Dev_cpe_type</cpe_type>
            <state>dev</state>
            <free_date>2009-03-22</free_date>            
        </service>
    </servicelist>
    <reply>
        <err_number>0</err_number>
        <err_description>a</err_description>
    </reply>
</GetAvailableServicesOut>

Any of you have a clue what's causing this problem???

/R

mhkay · March 12th, 2008, 06:02 PM

<xsl:value-of select="//na:service_id"/>

Get rid of that "//" - it causes selection from the root of the document, whereas you want selection underneath the context node.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

riffla · March 13th, 2008, 12:54 AM

Thanks Mhkay

Tried it, with some modification, and now it works fine
When removing the double slash from for each, there was no iteration in loop, but this works:
<xsl:for-each select="//na:servicelist/na:service">

while removing '//' from value-of expressions made it
Does this makes sense?

Thanks again

/R

samjudson · March 13th, 2008, 04:14 AM

It makes perfect sense when you understand what // actually does.

//na:service_id will select every single na:service_id element in the entire document, therefore <xsl:value-of select="//na:service_id"/> will always select the text value of the first element in the document.

When you are inside the xsl:for-each instruction the 'context' as it is called has changed, so you are now positioned at each service element in turn - so you you don't want to then select every single service_id element, you want the service_id element which is the child of the current service element.

To select something on the 'child' axis you can use the following convention: "child::na:service_id" - however in XSLT the child axis is the default axis, so can be removed and you can just use "na:service_id"

I'd recommend getting a good book on the subject if you plan to do much work with XSLT as you obviously need to get a handle on the basics.

/- Sam Judson : Wrox Technical Editor -/

riffla · March 13th, 2008, 04:45 AM

Thanks a lot

Of course it makes sense to me, reading your answer
And it's a good idea to dig deeper into this, since there's more of this job coming up

Worked a lot years ago, and memory is good, but too short :-)

Appreciate your help very much

Regards

/R

mhkay · March 13th, 2008, 04:52 AM

Question is, do you understand why it now works?

It's crucial to understand the notion of context and its effect on the values of path expressions.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

riffla · March 13th, 2008, 06:11 AM

Actually, I do, but to set this permanently I need to refresh and reinforce my knowledge in this. Worked a lot with XSLT-FO and PDF generation years ago, and that sure was a struggle with both XPATH and contexts, but also with positioning, but you tend to forget things you leave behind... And that's why these boards are so valuable, and of course other resources such as litterature, walk-thru's and so on

And I really like the commitment to help people here

Cheers

/R