- From: Julian Reschke <julian.reschke@gmx.de>
- Date: Wed, 17 Feb 2010 22:31:51 +0100
- To: Maciej Stachowiak <mjs@apple.com>
- CC: "Tab Atkins Jr." <jackalmage@gmail.com>, public-html@w3.org
On 17.02.2010 22:17, Maciej Stachowiak wrote: > > On Feb 17, 2010, at 7:41 AM, Julian Reschke wrote: > >> On 17.02.2010 16:30, Tab Atkins Jr. wrote: >> >>> .. >>> It's possible that we could define a new method for @ping, call it >>> PING. It would still be "unsafe", that is, not idempotent, by >>> definition. I'm not sure what possible benefits this could bring over >>> just using POST, though. >>> ... >> >> "safe" and "idempotent" are different things. > > Aren't all "safe" methods also "idempotent" by definition? Almost. Except for the side effects that a safe method is allowed to have, such incrementing hit counters etc.: "Naturally, it is not possible to ensure that the server does not generate side-effects as a result of performing a GET request; in fact, some dynamic resources consider that a feature. The important distinction here is that the user did not request the side-effects, so therefore cannot be held accountable for them." If you ignore those potential side effects as self-inflicted by the server (and not requested by the user), then yes, a safe method is also idempotent. Best regards, Julian
Received on Wednesday, 17 February 2010 21:33:17 UTC