Eliminate wasteful namespace declarations (optimise the XML output) #555
Description
I'm currently working some code and have noticed that for the sake of a smaller XML file, if you have a lot of declarations like this, the namespace duplication is very wasteful:
<saml2:AttributeValue xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="xs:string">demouser</saml2:AttributeValue>
Wouldn't it then make sense to include the namespace once at the root? This is related to #249 and #336 (the lack of declaration of namespaces for xs: types).
Is there a way to optimise this somehow? See the XML assertion in
pysaml2-built-assertion-with-individual-namespace-declarations.txt, it is 2346 bytes long.
An optimised version (see
pysaml2-built-assertion-with-root-namespace-declaration.txt ) is only 2038 bytes long.
While in the grand scheme of things this 308-byte difference doesn't look like much, it does mean a lot in the case we have, where every byte counts towards a 4096 octet limit. @rohe knows which case I refer to (Moonshot).