POST-WITH-NO-SIDE-EFFECTS method

Shel writes:
    In this case the one who controls this is the HTML writer, I think.
    
    In one case you could have a form defined using
    
	    <form method=POST action=/bla/bla>
    
    and in the other case you could have
    
	    <form method=POST-WITH-NO-SIDE-EFFECTS action=/bla/bla>
    
    The browser would have to transform that into a different request
    than the normal kind of POST.

This suggestion (a new kind of POST method) has a certain elegance
to it.  What worries me most is that it is probably incompatible
with existing proxies (or do they forward methods that they don't
know about?)  I would like to operate under the assumption that
we will never entirely get rid of HTTP/1.0 proxies, since as far
as I can tell, the computer industry has never entirely gotten
rid of anything.

I suppose we might be able to figure out techniques that decide
whether the entire request chain is HTTP/1.1, and allow the
browser to send POST instead of POST-W-N-S-E in that case.  But
this makes me nervous.

Aside from the proxy-compatibility issue (and perhaps the political
hassle of convincing the working group to add a new method), I
do like this idea.

From the protocol point of view, the simpler alternative (I
think) is for the server to always make such URIs either non-cachable
or (perhaps better) "always stale", which forces the cache
to transmit the request to the server even if it wants to
try to cache the response.  This should work with older proxies,
since they presumably do not ever use their caches to respond
to POST methods.  (Or am I wrong?)

However, I suspect that server implementors will hate this, because
it would require them to either provide a mechanism for server
administrators to control POST-cachability on a per-URI basis,
or to simply turn off POST-caching for servers that have any
URIs that need POST-W-N-S-E.  On the other hand, we'll probably
end up with something like this anyway, just to take advantage
of various Fresh-until:, Cache-control:, and Expires: mechanisms.

-Jeff

Received on Friday, 5 January 1996 03:02:51 UTC