Re: [Engine-devel] Issue with XML namespaces in engine-setup

On 04/12/2012 07:18 AM, Daniel Veillard wrote: > On Tue, Apr 10, 2012 at 01:54:51PM +0200, Juan Hernandez wrote: >> Hello, >> >> The code that we use in engine-setup to modify JBoss AS XML >> configuration files uses the following pattern: >> >> datasourceStr = ''' >> <datasource ...> >> ... >> </datasource> >> ''' >> >> xmlObj.addNodes("//datasource:subsystem/datasource:datasources", >> datasourceStr) >> >> This looks correct but is in fact generating a incorrect XML document, >> as the tags being added are not associated to a namespace. The resulting >> XML file will be correct, but the temporary representation in memory is >> not. This causes problems if you later, before writing out the modified >> file, try to use xpath expressions matching the added nodes: there will >> be no match. >> >> I would suggest that we change the pattern to something like this: >> >> datasourceStr = ''' >> <any_dummy_tag xmlns="urn:jboss:domain:datasources:1.0"> >> <datasource ...> >> ... >> </datasource> >> </any_dummy_tag> >> ''' >> datasourceNodes = libxml2.parseDoc(datasourceStr).getRootElement().children >> >> xmlObje.addNodes("//datasource:subsystem/datasource:datasources", >> datasourceNodes) >> >> This way both the representation in memory and the resulting file are >> correct. >> >> Le me know what you think. > > I think it's dangerous to move nodes from one document to another > especially if there is namespaces (I assume you're operating in an > environment on top of libxml2 as I saw a reference to it ;-) > > For libxml2 there is an API in C: > http://xmlsoft.org/html/libxml-parser.html#xmlParseInNodeContext > which could do what you expect. Maybe there is a binding/wrapper > available you could use. Thanks Daniel, that looks certainly better/easier than what I am proposing. We use libxml2-python, but I can't locate that method there. Do you know if it is possible to use it from python?