Re: [xml] Relative paths and top-level xpath queries

[Daniel Veillard <veillard redhat com>]

On Mon, Apr 05, 2004 at 12:11:01PM -0700, Greg Chapman wrote:
> I am a complete newbie at xpath and libxml2, so I apologize if I'm missing
> something basic.  Anyway, I'm using the v. 2.6.6 of the Python bindings for
> libxml2 (Python 2.3.3, Windows XP).  I was surprised at the following result
> (test1.xml is the same as that in the C source distribution, i.e. "<doc/>"):
> 
> >>> import libxml2
> >>> doc = libxml2.parseFile("test1.xml")
> >>> context = doc.xpathNewContext()
> >>> context.xpathEval("doc")
> []
> 
> Changing the above to a non-relative path gets the only node:
> 
> >>> context.xpathEval("/doc")
> [<xmlNode (doc) object at 0x146ee90>]
> 
> 
> Is this the correct behavior?  I ask because it seems that Microsoft's
> XPathNavigator.Evaluate method does return the doc node when given a "doc" path.

  Seems to be a matter of initialization of the context node,
>>> import libxml2
>>> doc = libxml2.parseFile("tst.xml")
>>> context = doc.xpathNewContext()
>>> context.xpathEval("doc")
[]
>>> doc.xpathEval("doc")
[<xmlNode (doc) object at 0x8247664>]
>>>

  confirmed by

>>> import libxml2
>>> doc = libxml2.parseFile("tst.xml")
>>> context = doc.xpathNewContext()
>>> context.setContextNode(doc)
>>> context.xpathEval("doc")
[<xmlNode (doc) object at 0x8185b0c>]
>>>

Daniel

-- 
Daniel Veillard      | Red Hat Network https://rhn.redhat.com/
veillard redhat com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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