Avoid duplicating namespaces during xml serialization using javascript -

the following code

var ns1 = 'hello:world1',     doc = document.implementation.createdocument('nsdoc', 'doc', null),     outer = doc.createelement('outer'),     s = new xmlserializer(),     elm;  outer.setattribute('xmlns:ns1', ns1); elm = doc.createelementns(ns1, 'inner');  outer.appendchild(elm);  console.log(s.serializetostring(outer)); 

outputs following xml document in chrome , firefox.

<outer xmlns:ns1="hello:world1">   <inner xmlns="hello:world1"/> </outer> 

while technically still valid, there way remove duplicate ns declaration or there better api using setup namespaces on parent node use in children? eg, preferred document follows:

<outer xmlns:ns1="hello:world1">   <ns1:inner/> </outer> 

figured out how gain better control on how namespaces serialized via use of domparser , little bit of uncomfortable handwritten xml (but root nodes). following javascript did this:

var parser = new domparser(),     s = new xmlserializer(),     dom1 = parser.parsefromstring('<doc xmlns="one"></doc>', 'text/xml'),     dom2 = parser.parsefromstring('<outer xmlns="one" xmlns:ns3="hello-world"></outer>', 'text/xml'),     myelm = dom2.createelementns('hello-world', 'ns3:inner');  dom2.documentelement.appendchild(myelm); dom2.documentelement.attributes.removenameditem('xmlns'); dom1.documentelement.appendchild(dom2.documentelement); console.log(s.serializetostring(dom1)); 

this outputs following xml in chrome (26.0 on mac), firefox (21.0 on mac) , opera (12.15 on mac -- though opera includes xml declaration ok needs)

<doc xmlns="one">   <outer xmlns:ns3="hello-world">     <ns3:inner/>   </outer> </doc>