W3C home > Mailing lists > Public > www-tag@w3.org > April 2002

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: <>
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.


Graham Klyne
Received on Wednesday, 17 April 2002 04:55:33 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 22:55:51 UTC