[Tclhttpd-users] Re: Checking Page flow redirects etc..????

[Colin M. <co...@ch...>]

On Fri, 2004-10-08 at 00:09, Nicolas Boretos wrote:

> Is there any simple or built-in way in tclhttpd for checking your page 
> flow, meaning verify that you got to a page from another???

Not that I know of, but it would be a cool project.

What you want (I think) is to drive each user's interaction from a state
machine.  Their session starts in state 0, then depending on the inputs
they submit, it moves to a different state.

You define a FSM (aka DFSA) which determines which transitions are
legal.

There's a tcllib FSM package.  Could be useful for this kind of thing.

> currently doing cludges like the following..
> 
> if {[string match "$::env(HTTP_REFERER)" 
> "http://$::env(HTTP_HOST)/rubia/parts.tml?record_id=[ncgi::value 
> record_id]&rec_id=[ncgi::value rec_id]&session_id=[ncgi::value 
> session_id]&use_name=[ncgi::value use_name]"]} {
> rubia::populate_checkboxes month_collected  [ncgi::value record_id] 
> month_collected session_id [ncgi::value session_id] use_name 
> [ncgi::value use_name]
> rubia::populate_checkboxes month_traded  [ncgi::value record_id] .blahhhhhh
> 
> Or how to check whether form is referred or self posted...??
> 
> proc rubia::is_self_posted {} {
>         if {$::env(REQUEST_URI) != "[eval join 
> {http://$::env(HTTP_HOST)$::page(url)}]"} {
>                         ####Form is refered, so lock record####
>                            return 0
>         } else {
>                 ####Form is self-posted, write data etc
>         return 1
>         }
>  }
> 
> or the inverse...
> 
>  proc rubia::is_referred {} {
>         if {$::env(HTTP_REFERER) != "[eval join 
> {http://$::env(HTTP_HOST)$::page(url)}]"} {
>                         ########
>                            return 1
>         } else {
>                 ####Form is self-posted, write data etc
>         return 0
>         }
>  }
> 
> This used in the .tml pages to decide what action to take ...
> if {[rubia::is_self_posted]} { do someting...
> 
> This gets painfull after a while...

Word.
-- 
Colin McCormack <co...@ch...>