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Re: draft findings on Unsafe Methods (whenToUseGet-7)

From: Graham Klyne <GK@ninebynine.org>
Date: Thu, 18 Apr 2002 17:12:07 +0100
Message-Id: <5.1.0.14.2.20020418170232.038c8120@joy.songbird.com>
To: Paul Prescod <paul@prescod.net>
Cc: www-tag@w3.org
At 12:34 AM 4/18/02 -0700, Paul Prescod wrote:
> > - an operation that is idempotent:  has no further side effects if repeated
> > after it has been performed once
>
>The HTTP specification uses the term idempotent to mean idempotent.
>
>http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.1.2
>
>PUT is safe but not idempotent.

Yup, what it says there is exactly what I meant.  And according to that 
reference, PUT is idempotent.

And I really don't see how PUT can be regarded as safe.  Unfortunately, the 
definition of safe in terms of accountability is, to me, rather vague.  I 
can't see how to test it.

The section immediately preceding the one you cite mentions "actions they 
might take which may have an unexpected significance to themselves or 
others" -- in a web context, it seems to me that any action which changes 
what is visible on the web is potentially significant, hence my attempt to 
characterize it in terms of visible side effects.

#g


-------------------
Graham Klyne
<GK@NineByNine.org>
Received on Thursday, 18 April 2002 12:40:27 GMT

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