Hi Garvin,



see my comments below.




Garvin Riensche wrote:
I should have written "tiding up namespaces" instead of "removing" as 
I don't want to loose them. I just want to clean them up.



Maybe I am wrong but I thought that if the "method" element has the 
namespace "http://new.element", all child elements will belong to this 
namespace too. So there's no need to write the namespaces of the child 
elements to the output.

No. The method element has indeed the mentioned namespace. All child 
element will have the namespace that is bound as the default namespace, 
which, when not defined, is the default empty namespace. To emphasize 
this, the serializer puts xmlns="" on the main element, to make sure the 
child elements are in the default empty namespace.



To work with namespaces it is best practice to use the prefixes you 
formerly declared.




The namespaces are as you proposed defined in the stylesheet element 
on top of the stylesheet:



<xsl:stylesheet version="2.0"
    xmlns:srcml="http://srcml.de"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:srcml-new="http://new.element"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:meta="http://srcml.de/meta">

Good, that's what I meant. Now, do not use the namespace attribute 
anymore in the xsl:element instruction. Instead, use the prefix you 
declared in the the xsl:stylesheet element. The name of xsl:element must 
contain a QName. The first part of a QName is the prefix of the 
namespace. This makes the namespace attribute (in your case) redundant.
...



I don't really understand why the namespaces show up in the elements 
although they are declared on top of the stylesheet. 

They show up because you specifically declare them again (using the 
namespace attribute of xsl:element). Don't do that, use the prefix 
instead, and your problem goes away. Also, when the name of the element 
is a fixed name (i.e., does not come from a variable or XPath 
expression) then it is normally better and more readable to not use 
xsl:element at all but just use a literal result element (i.e., just 
write <method> or <myns:method> instead of <xsl:element name="method"> 
or <xsl:element name="myns:method">)



Also, in the case that your resulting document does not have a single 
root element (which is not allowed in XML but is allowed in XSLT output 
for various reasons) every "rooted" element must have all namespaces 
declared again and again. Once there's a single root element, the 
serializer can optimize by putting the namespaces there.



And I am wondering where the xmlns="" comes from. It would just look 
nicer if I could get rid of the namespaces in the elements. If I use 
the Syntax srcml-new:modifiers in the template instead of just 
"modifiers" there is still the complete srcml-new namespace definition 
in the output.



It seems to me that the redeclaration of the default namespace to an 
empty namespace (the default of XML + NS) is not necessary in your case, 
but I haven't seen enough of your code to justify that statement. The 
reason that a serializer will redeclare the default namespace to the 
empty namespace can be one of ambiguity, or because you ask him to. 
Again, removing all the extra namespaces in your code (xsl:element and 
xsl:attribute) will make your code cleaner and probably removes this 
redundant declaration too.



Note that over-declaration of your namespace means that your document is 
wrong. If your document is used for machine reading (i.e. further 
processing) and the namespaces are otherwise correct, then there's 
technically no necessity to remove the redundant namespaces (other then 
space, but space is cheap nowadays).



Cheers,
-- Abel Braaksma