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

From: Graham Klyne <GK@ninebynine.org>
Date: Wed, 17 Apr 2002 09:55:02 +0100
Message-Id: <5.1.0.14.2.20020417095020.00a943a0@joy.songbird.com>
To: <LMM@acm.org>
Cc: <www-tag@w3.org>
At 10:10 PM 4/16/02 -0700, Larry Masinter wrote:
>No, it isn't 'utterly pointless'. One of the primary use cases for
>knowing about whether a method was 'safe' was to decide whether it
>was OK to re-do the method without warning the user, as is now done
>with POST. A Safe POST could be redone (click Reload) without prompting,
>and knowing after the fact was as useful as knowing before.

This suggests two possible ideas of "safe":

- an operation that has no (externally visible) side effects

- an operation that is idempotent:  has no further side effects if repeated 
after it has been performed once

In the context of GET, I think the first is desired/needed.

#g


-------------------
Graham Klyne
<GK@NineByNine.org>
Received on Wednesday, 17 April 2002 04:55:33 GMT

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