'Twas brillig, and Fire Eye'd Boy at 01/04/09 21:36 did gyre and gimble:
IMHO the back button won't 'break': It simply enables the user to go back to a previous invalidaded form state.
Only if the user reposts the data, and depending on the browser in question, this may or may not be particularly user friendly. Personally, I'd like to avoid all doubt here, but each to their own :)
IMO the POST - redirect - GET pattern is meant to prevent the submitting of *valid* post data which could lead to unwanted multiple sensitive transactions. As long as the data is invalid there is nothing to worry about. I'ld even argue that it is more userfriendly to allow the user to track back with the backbutton what form states failed submission.
I respectfully disagree. If the user is entering some details and gets it wrong two or more times and decides to go back to change some other data elsewhere that will impact his changes, then they cannot do that via the back button without reposting (which to an average user is rather confusing process in itself).
There is also the (arguably unlikely) scenario that the code may change while the user is using the app and previously invalid data is subseqently considered valid. The user may think "Hmm do I want to repost this data? Yes, because I know it's invalid and it will be rejected. Oh Carp, it was accepted this time... WTF?".
Thanks for your input tho'. It's always nice to discuss these things. Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mandriva Linux Contributor [http://www.mandriva.com/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/]
