Re: Resubmitting POSTS (Was Re: Proxies changing POST to GET?)

Alastair Aitken CLMS (ZPALASTAIR@CLUSTER.NORTH-LONDON.AC.UK)
Sun, 1 Jan 1995 00:17:02 +0100

M.J.Cox@uk.ac.bradford writes @ Wed, 21 Dec 1994 10:23:42 +0100
>Ari Luotonen wrote:
>> This is because some clients don't use POST correctly when reloading the
>> page, but use GET instead; NCSA Mosaic definitely has this bug,

>This implies that reloading a page should POST the original data again:
>not such a great idea if a user has just submitted an order and ends up
>making several identical orders.

>It isn't in any specs, so what is the expected action?

> Do a GET on the same URL? (broken browsers do this now)
> Disable the ability to Reload the page?
> Ask the user if they want to resubmit the POST? (Netscape now does)
> Resubmit the Post anyway? (Netscape used to)

>In the latter case sites that accept forms will have to watch out for
>identical copies or implement some hidden session numbers.

I am using Netscape (a browser) to handle forms for maintaining data on
NCSA's httpd (a server). Sometimes only small changes to the data are
needed so that an IP (Information Provider) may be POSTing the form and
returning to it several times to upload data. This is easier than filling
the whole form in each time. I use perl to process the name-value pairs
and if there is an exact match on the POSTed data and a record in my files
then I issue an error message accordingly.

My version of Netscape does not ask the user if s/he wishes to rePOST the
form - it just does it repeatedly if asked. I am using 1.0 in windows. I
would be very disappointed if either of your first two options were
implemented as 'solutions' to this. I think responsibility lies with the
webmaster or technical staff to ensure the integrity of the systems that
manage the data whilst, true to data prep principles, responsibility for
the data itself lies with the data owners. On this basis it is my job to
ensure that the systems do not allow multiple POST's of the same data
whilst the quality of that data is down to the IP.

Accordingly, I agree with Ari that Mosaic's failure to rePOST a form full
of data is a bug, or at least an ill-considered feature. My version 1.0
Netscape does a rePOST and not a GET on subsequent calls.

Alastair.