Hi Anne,
Thanks for your reply. (We are assuming that this is not a formal reply
from the webapps WG.)
The XHTML 2 working group discussed the XHR draft at a recent
teleconference, and I was asked to send in a brief comment. Basically,
the XHTML 2 Working Group is concerned that the draft appears to have a
dependency on HTML5. On closer inspection, it is not clear whether
this dependency is completely necessary. Further, linking the spec to
HTML5 will delay its deployment and incorporation into other languages
that have a vested interest in portable scripting (e.g. XHTML 1, XHTML
2, XForms).
The concepts defined in HTML5 are important for getting interoperable
implementations of XMLHttpRequest. I don't think deployment is
necessarily an issue as XMLHttpRequest is already deployed. Now we just
need to make sure the various user agents get in line with respect to
the behavior they each have.
It's not entirely clear to me why XMLHttpRequest needs to be
incorperated into a language. In fact, it was incorperated in HTML5 at
some point and we splitted it out. (Given the amount of work this cost
me I'm still not sure whether it was worth the cost, but it has been an
interesting exercise nonetheless.)
Finally, it appears that the dependecy is slightly backwards, since the
requirement is that HTML5's document "Window" object support the
XMLHttpRequest interface.
Actually, no. The requirement is that objects implementing the HTML5
Window _interface_ also support the XMLHttpRequest constructor.
Furthermore, the definition of HTML5 Window is important here in case of
URI resolution in cross-frame scenarios.
Also, that is not the sole dependency the XMLHttpRequest specification
has on HTML5.
Our request is that this dependency be removed (or that the connection
be made informative instead of normative) so that all interested
constituents can take advantage of this important interface as soon as
possible.
I don't think this is possible. Feel free to go through the
public-webapi mailing list archives to find more detailed discussion on
this subject if you feel the above is not sufficient:
There seem to be several options:
1. XMLHttpRequest is irrevocably bound to HTML5.
If that is the case then there seems to be no reason to develop this
spec outside of the HTML5 WG, or indeed for developing as a separate spec.
2. XMLHttpRequest is host neutral, and therefore can be used in different
environments.
If that is the case, and it would seem preferable since there are
several other technologies that are able to use this, then it seems good
to make it as widely adoptable as possible. It seems like there are two
ways to do this:
a. copy the restrictions due to HTML5 into this document, so that it is
free-standing
b. remove the restrictions due to HTML5, and ensure that they are added
to that spec, and let languages that use it specify the necessary
restrictions needed to make it work in that environment.
Which of these do you think best apply to XMLHttpRequest?
There seem to be several technologies in W3C that could use
XMLHttpRequest; SMIL and XForms come readily to mind. Would you be able to
enumerate what it is in XMLHttpRequest that is so bound to HTML5?
Thanks!
Best wishes,
Steven Pemberton
