Re: [xml] XPath evaluation

[Nic <nferrier tapsellferrier co uk>]

"CAPRON Patrick" <capronpa e-i com> writes:

> Hi,
>  
> I don't understand how libxml2 is evaluating some expressions.
>  
> I have an XML who looks like :
> <?xml version="1.0"?>
> <REQUEST>
>     <HEADER/>
>     <CODEAPPLI>TARGET2</CODEAPPLI>
>     <BICCOR>CMCIFRPP</BICCOR>
>     <NMSRVLOG>NMSRVLOG</NMSRVLOG>
>     <NMRQTLOG>NMRQTLOG</NMRQTLOG>
>     <REQUESTREF>REQUESTREF</REQUESTREF>
>     <RQTSTATUS>RQTSTATUS</RQTSTATUS>
>     <SwInt:RequestPayload>
>         <AppHdr xmlns="urn:ssp.ApplicationHeader$ahV10">
>             <From>
>                 <Type>NAME</Type>
>                 <Id>PM</Id>
>             </From>
>             <To>
>                 <Type>NAME</Type>
>                 <Id>PM</Id>
>             </To>
>             <MsgRef>ABCDEF</MsgRef>
>             <CrDate>2006-04-19T12:00:00</CrDate>
>         </AppHdr>
>         <Document xmlns="urn:ssp.pm.GetLimit$camt.009.001.02">
>             <camt.009.001.02>
>                 <MsgId>
>                     <Id>REFERENCE12345</Id>
>                 </MsgId>
>                 <LmtQryDef>
>                     <LmtCrit>
>                         <NewCrit>
>                             <SchCrit>
>                                 <AcctOwnr>CMCIFRPAXXX</AcctOwnr>
>                             </SchCrit>
>                         </NewCrit>
>                     </LmtCrit>
>                 </LmtQryDef>
>             </camt.009.001.02>
>         </Document>
>     </SwInt:RequestPayload>
> </REQUEST>
>  
> I use the xmlXPathEvalExpression function.
> If I use the expression : /REQUEST/RequestPayload/Document the function returns 0 node.
> If I use the expression : /REQUEST/RequestPayload/*[name()='Document'] it returns the node I'm
> looking for.
>  
> Could anybody explain me why there is a difference between this two expressions ?
> I believed that they were the same...
> Is it because of the xmlns ?

Yes, I think so.

But I don't know why the second one matches at all because
RequestPayload isn't in an empty namespace either; so I expected it to
match if you did:

   /REQUEST/SwInt:RequestPayload:urn:ssp.pm.GetLimit$camt.009.001.02:Document

To get xpath to match this you could register the namespaces with tags
and then eval the expressions.


Nic Ferrier
http://www.tapsellferrier.co.uk