Keith Moore writes:
So I'm currently thinking that Archived-At needs to supply more
information: namely the content types that are available. An
alternative might be to use a HEAD request to find out what
content-types are available.
I think the problem you are raising is a generic URI problem, and not just
a problem with this particular header.
AIUI, a URI gives you access to a "resource"; i.e. it tells you where to
find it. It tells you nothing about what to do with it when you have got
it, except what is implicit in the "scheme".
So if the scheme is 'ftp', then all you know is that you are going to get
a file of some sort.
If the scheme is 'imap', then you know that the object to be retrieved
will be something like an email message, and the rules for imap URIs will
doubtless tell you much more.
Now one of the possible benefits of the 'http' scheme is that the object
that comes back should have a Content-Type header. And what we want is for
this Content-Type to be message/rfc822.
So what Martins draft needs to say is something like "If the scheme of the
URI is 'http', then the entity that is returned SHOULD have the
Content-Type message/rfc822". Then whatever system asked for the
Archived-At object to be retrieved has a decent chance of being able to
display and process it like an email.
Either way, this document probably needs to say some things about
- use of different representations of email messages, with native
(message/rfc822) format being strongly encouraged as the primary
format and HTML as a useful alternative.
Yes, see above.
- use of HTTP vs. IMAP (maybe also mentioning POP or even NNTP)
as an access protocol
Yes.
- how a mail reader (or for that matter a web browser) should decide
whether to handle the message itself or hand it off to a different
tool.
You can't really give detailed instructions in a standard about how
individual readers or browsers are supposed to behave. The general
intention is that all readers/browsers that recognize Content-Type headers
are supposed to use the best available tool for handling that Content-Type
(possibly even using a special plugin). Naturally, some current systems
make a better job of this than others :-( .
--
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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