[xquery-talk] Question about default context node

[Michael Kay]

> 
> Which mechanism would you recommend for input data, external var or 
> context node? My use case would be one XML document in, one XML 
> document out, similar to an XSLT transformation with JAXP/TRAX.

Whatever is most convenient. There's no real difference internally. 
> 
> Do you know if other implementations also support the context node 
> concept?

I haven't been tracking other implementations, sorry!

Michael Kay


> 
> thanks,
> alex 
> 
> 
> > The key thing here is appendix C.2, which indicates that there is no
> > language-predefined default for the initial value of the context 
> item, but
> > that a value can be supplied "by the implementation" - which in 
> practice
> > means that the implementation can provide means for the user to set 
> a value
> > via an API. An implementation could if it wished always set this to 
> a fixed
> > value (for example it could always set the initial context item to 
> the
> > integer zero or to a random number) but that seems an unlikely 
> choice to
> > make. The language spec is very careful to steer clear of 
> API issues.
> > 
> > As for XQJ, I think there are lots of things missing from the 
> current drafts
> > of XQJ. I suspect (I certainly hope) that the final spec will move 
> on a fair
> > bit from the draft that we've seen.
> > 
> > Michael Kay
> > 
> > > -----Original Message-----
> > > From: talk-bounces at xquery.com 
> > > [mailto:talk-bounces at xquery.com] On Behalf Of Alex
> > > Sent: 17 September 2004 18:27
> > > To: talk at xquery.com
> > > Subject: [xquery-talk] Question about default context node
> > > 
> > > Hi,
> > > 
> > > is a default context node part of the XQuery standard? 
> I'm getting 
> > > conflicting messages. For one, I heard statements that you 
> > > need to use 
> > > doc(), collection() or external variables to pass in data to an 
> > > XQuery. On the other hand, implementations like Saxon provide 
> methods 
> > > like setContextNode() in their Java API so a simple XPath 
> like /a/b/c 
> > > is also a valid XQuery that makes sense. I like the context node 
> > > option because of its simplicity but am not sure if it's 
> standard. 
> I 
> > > haven't seen support for it in XQJ.
> > > 
> > > I would appreciate any clarification and references to the XQuery 
> > > standard concerning context nodes set from the API.  
> > > 
> > > Thanks,
> > > alex
> > > _______________________________________________
> > > talk at xquery.com
> > > http://xquery.com/mailman/listinfo/talk
> > > 
> > 
> > 
> > 
> 
> -- 
> 
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