Hi,
Jacek Konieczny wrote:
On Mon, Feb 28, 2005 at 11:45:34AM +0100, Kasimier Buchcik wrote:
Jacek Konieczny wrote:
Hello,
I have a big problem with libxml2 python bindings. The problem also occurs in the C API, but it is easily fixable there (so it can be just called a 'feature').
Here is the test case (python code):
import libxml2 doc=libxml2.parseDoc("<a xmlns='http://a/'><b xmlns='http://b/'/></a>") a = doc.getRootElement() b = a.children print `doc.serialize()` print "Ns of <b/>: %r" % (b.ns().content,) b.setNs(a.ns()) print `doc.serialize()` print "Ns of <b/>: %r" % (b.ns().content,)
The output is: '<?xml version="1.0"?>\n<a xmlns="http://a/";><b xmlns="http://b/"/></a>\n' Ns of <b/>: 'http://b/' '<?xml version="1.0"?>\n<a xmlns="http://a/";><b xmlns="http://b/"/></a>\n' Ns of <b/>: 'http://a/'
[...]
The biggest problem is, that I cannot fix that using only the Python API. xmlNode.reconciliateNs() does nothing about that.
There was a bug in xmlSearchNsByHref, which caused xmlReconciliateNs to fail in this scenario. Fixed in CVS (tree.c 1.339).
After applying the patch on libxml2-2.6.17 the output is:
'<?xml version="1.0"?>\n<a xmlns="http://a/";><b xmlns="http://b/"/></a>\n' Ns of <b/>: 'http://b/' '<?xml version="1.0"?>\n<a xmlns="http://a/";><default:b xmlns="http://b/"; xmlns:default="http://a/"/></a>\n' Ns of <b/>: 'http://a/'
That is a correct XML, but still does not satisfy me. A prefix has been added to <b/> and the unneccessary namespace declaration is still there.
Yes, xmlReconciliateNs does not remove unreferenced namespace declarations, since it cannot know if those declarations are needed for following processing or not; it goes the save way in preserving them. I recommend implementing a "xmlCleanupNsDecl" function, removing unreferenced namespaces from a given branch. Adding generated prefixes is OK - take a look at the namespace normalization algorithm of the W3C [1]; preserving prefixes is not always possible if serializing, so you should not rely on it.
For my needs that is still unacceptable. I implement an XMPP implementation and for backward-compatibility with many Jabber clients I need to use default namespaces (no prefixes) in some places.
I see, OK so you need total control of the declarations.
I think a function to remove (or override) namespace declaration from a node is what I need and I will request it via Bugzilla.
Exactly.
[1] http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/namespaces-algorithms.html
Regards,
Kasimier _______________________________________________ xml mailing list, project page http://xmlsoft.org/ [email protected] http://mail.gnome.org/mailman/listinfo/xml
