On May 12, 2008, at 5:52 AM, Bjoern Hoehrmann wrote:
* Maciej Stachowiak wrote:
A function is not a particularly convenient way to specify a
namespace
mapping, and it creates these error handling issues as well as
causing
problems with case (in)sensitivity. Even though NSResolver is what
XPath uses, wouldn't it be simpler to just accept an object that
provides the relevant namespace mappings?
That would preclude simple solutions to the resolution problem like
http://lists.w3.org/Archives/Public/public-webapi/2008Apr/0204.html
I originally thought that >this could be a JSON-style JavaScript
object,
but it seems to me that a DOM node would actually work just as well.
Most of the time, you want to use the namespace prefixes in effect
for
the root element, and if not, then it is pretty simple to construct a
DOM node with all the right xmlns declarations.
That would not have the particular problem above, but many others.
I do not think you want the prefixes on the document element most
of the time, it is not as easy to create such a node as you suggest,
and all in all this would likely cause great confusion. It's hard
to imagine the typical user of this API using code like this:
var node = document.createElementNS(null, "magic-ns-element");
node.setAttributeNS('http://www.w3.org/2000/xmlns/',
'xmlns:xht', 'http://www.w3.org/1999/xhtml');
node.setAttributeNS('http://www.w3.org/2000/xmlns/',
'xmlns:svg', 'http://www.w3.org/2000/svg');
node.setAttributeNS('http://www.w3.org/2000/xmlns/',
'xmlns:mml', 'http://www.w3.org/1998/Math/MathML');
I think this would be a very bad idea.
This does not look much better (it does avoid repeatedly mentioning
the xmlns namespace at least):
function resolver(prefix) {
if (prefix == "xht") {
return "http://www.w3.org/1999/xhtml";;
} else if if (prefix == "svg") {
return "http://www.w3.org/2000/svg";;
} else if (prefix == "mml") {
return "http://www.w3.org/2000/xmlns/";;
}
return null; // ???
}
However, this does look better:
var namespaces = {xht: "http://www.w3.org/1999/xhtml";; svg: "http://www.w3.org/2000/svg
"; mml: "http://www.w3.org/1998/Math/MathML"; };
I therefore make a second proposal to accept either vanilla JS objects
of this format or DOM nodes, instead of NSResolver objects.
Regards,
Maciej
