[xquery-talk] querying an xml file with namespaces
michael.michaud at free.fr
Thu Jan 12 08:07:16 PST 2006
Thank you Wolfgang,
You helped me to understand how it works.
Now I must have a closer look at the XQuery functions syntax.
I also noticed some namespace-relative methods in the xom Element class,
which may be helpful.
Wolfgang Hoschek a écrit :
> On Jan 11, 2006, at 2:17 PM, Michaël Michaud wrote:
>> I try to query an xml file with nux XQueryUtil.
>> First time, i get messages such as
>> "Prefix md has not been declared"
>> I could get the result by adding something like
>> "declare namespace md="http://www.isotc211.org/2005/gmd";"
>> in front of my query string.
> That's the standard and hence recommended way of doing it.
>> Now I try to read the namespaces first with another query
>> XQueryUtil.xquery(node, "//namespace::*")
>> to automatically add the namespaces in front of my main query,
>> but I get the message :
>> "The namespace axis is not available in XQuery"
> This simply won't work. The namespace axis has been deprecated by the
> W3C, so Saxon followed suit and disabled it a few releases ago by
> toggling an internal flag. Namespaces continue to be available
> supported, of course. It's just the namespace axis iteration that's
>> Question : what is the simple method to query an xml file using
>> namespaces ?
> Depends on what you're trying to do.
> You could write yourself a Java method or XQuery function that
> computes the namespaces in scope for a given element, then precede
> the query with the relevant declarations. For example, using standard
> XQuery functions such as fn:namespace-uri(Node) or similar.
> The best solution might be to argue on the XOM mailing list for a
> public method returning the namespace declarations of a XOM
> XPathContext, such as nu.xom.XPathContext.toMap(). If this would be
> public I'd consider adding a query method that takes an XPathContext
> as additional input parameter, similar to the XOM XPath functionality.
> talk at xquery.com
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