W3C home > Mailing lists > Public > public-html@w3.org > January 2012

Re: Meta element to prevent resending post data

From: Marat Tanalin | tanalin.com <mtanalin@yandex.ru>
Date: Fri, 27 Jan 2012 21:56:24 +0400
To: Kornel Lesiński <kornel@geekhood.net>
Cc: public-html@w3.org
Message-Id: <81921327686984@web65.yandex.ru>
27.01.2012, 21:44, "Kornel Lesiński" <kornel@geekhood.net>:
> On Fri, 27 Jan 2012 14:09:02 -0000, Marat Tanalin | tanalin.com
> <mtanalin@yandex.ru> wrote:
>
>>  Thanks, Kornel. But the proposal is _not_ about adding something to
>>  _all_ pages (that would be pointless).
>
> Of course I've meant all relevant pages, i.e. those which use POST and
> don't use POST-redirect-GET workaround.
>
> It's still an "all pages" kind of problem, because it requires webmasters
> to know and care about the problem, know the workaround, and to add it to
> existing (sometimes unmaintained) pages.
>
>>  The proposal is about minimizing negative user-experience impact _when_
>>  server-side redirect would/should be used, but is _technically
>>  impossible_.
>
> What I'm trying to say is that there is another technical possibility of
> minimizing negative user experience, and it doesn't involve servers/pages
> at all. It's provably possible, because it's been done by at least one
> browser already.
>
>>  So there are just two options in such situations:
>>  1. put up with negative impact caused by inability for user to refresh
>>  page and/or potential resending of POST data when user refreshes the
>>  page;
>>
>>  2. use the proposed meta element to prevent resending POST data when
>>  server-side (self-)redirect would be used if it was technically
>>  available.
>
> No, this is a false dichotomy. There is at least a third option:
>
> * History navigation (Back button) should always read POSTed pages from
> cache, even if pages had Cache-Control: no-cache set (this is
> RFC-compliant). This way there is no unexpected resubmission happening
> automatically, and—unless user forces browser to clear the cache—there is
> no need to ask any questions or switch to GET.
>
> * Reload button on POSTed pages should always use POST. This way user can
> still re-submit if they want to.

Unfortuntely, that's wrong. Consider that a page makes server-side redirect after POST request. User cannot resend POST data after the redirect. My proposed meta element should have exactly same effect.

For even more clarity, see also branch of my discussion with Tab:

http://lists.w3.org/Archives/Public/public-html/2012Jan/0168.html
http://lists.w3.org/Archives/Public/public-html/2012Jan/0172.html
Received on Friday, 27 January 2012 17:56:58 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 9 May 2012 00:17:43 GMT