Robin Berjon wrote:
There are quite a few services out there that return XML — it would
be disingenuous to pretend otherwise. The addition of x-site requests to
the stack makes these even more available. XHR supports XML natively,
including namespace. Selectors support namespaces natively.
Implementations already support that — exposing it at the API level is
hardly a massive cost. So apart from saying that all of these are wrong,
or saying that XML, XHR, Selectors aren't part of the web stack I can
hardly see where your argument is going.
No-one is disputing the fact that those tools exist and that they could
be used for XML with namespaces. But are those tools being used in ways
that utilise namespaces in useful ways, such that having them exposed at
the selector API level would be either useful or even necessary?
How about we take a look at some public website APIs using XML that
could be suitable for use in cross site requests, and see which, if any,
could possibly benefit from supporting prefixes in this API?
Twitter: http://apiwiki.twitter.com/Twitter-API-Documentation
Does not use namespaces at all, would not benefit from it being added to
this API.
Flickr: http://www.flickr.com/services/api/
Again, does not use namespaces at all.
Validator.nu: http://wiki.whatwg.org/wiki/Validator.nu_Web_Service_Interface
http://wiki.whatwg.org/wiki/Validator.nu_XML_Output
This does use namespaces in the XML version of it's API. It nests
fragments of the XHTML markup within the <message> and <extract>
elements. These tag names don't clash with any in XHTML, and so they
can be selected without bothering about namespaces, or by using a
selector like
"messages>error>elaboration"
To select any of the XHTML itself, it's easy enough to use a selector
like:
"error>elaboration div" or "info>message code"
The source element does clash with the source element in HTML5, but it
can be easily and unambiguously selected using "messages>source".
So, even if a script opted for the XML output, there is no clear
dependency on using namespaced selectors here.
Besides, all of those APIs mentioned also offer JSON output, which is
much more optimised for use in JavaScript environments where cross site
requests will be most common.
So what other sorts of APIs do you have in mind which would greatly
benefit from namespace support in selectors API? It would help if you
could find some other APIs and illustrate with some real world sites
that use them, where namespace-supporting APIs are utilised for good
reasons on the client side.
--
Lachlan Hunt - Opera Software
http://lachy.id.au/
http://www.opera.com/
