[xml] Rer: Re: XPath question

["Erik F. Andersen" <ea ascott dk>]

Hi!

The prefix is not "nil". NIL is Delphi syntax for a NULL pointer in C. If you look at the definition for xmlns in <DenDynamiskeBlanket> there is no prefix specified.

It is quite obvoius looking at the source in xpath.c why xmlXPathRegisterNs won't work with a NULL prefix. It return -1. If I register the namespace with any prefix for instance xmlXPathRegisterNs("nil", "http://www.medcom.dk/DenDynamiskeBlanket/2006-01-30/";) XPath will work if I just remember to prefix my queries witj "nil" as you suggest.

I just don't get it why it is necessary to register the namespace at all...

Regards,
Erik

>>> Rob Richards<rrichards ctindustries net> 21.11.2006 14:29:39 >>>
Erik F. Andersen wrote:
> Hello!
>
> I use LibXML version 2.6.17 on Windows and I have a problem with an XML document where I cannot get XPath to return any nodes.
>
> The start of the XML looks like this:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <DenDynamiskeBlanket xmlns="http://www.medcom.dk/DenDynamiskeBlanket/2006-01-30/";
>     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
>     xsi:schemaLocation="http://www.medcom.dk/DenDynamiskeBlanket/2006-01-30/ file:/C:/Documents%20and%20Settings/Jacob/workspace/Den%20Dynamiske%20Blanket%20Fremviser/xml/xsds/ddb.xsd">
>     <Form>
>         <Identifier></Identifier>
>         <SentDateTime>2002-02-02T23:23:23</SentDateTime>
>         <TypeCode>LÆ255</TypeCode>
>         <VersionCode></VersionCode>
>         <StatisticalCode></StatisticalCode>
>         <PageStock>A4</PageStock>
>         <Graphics>
>
> My problem is that no matter what I do I cannot locate any nodes with XPath. I tried registering the namespace using xmlXPathRegisterNs (the prefix is nil). Is there a problem with the XML above or am I doing something wrong?  If I remove the xmlns attribute I have no problems. I think the XML is wrong but I don't know what it is...
>   
Are you using the registered prefix in your query?
i.e. //nil:Form should return all the Form element nodes (assuming you 
registered "http://www.medcom.dk/DenDynamiskeBlanket/2006-01-30/"; with 
the prefix "nil")

Rob