Perhaps this debate has been had before but I didn't see it.  I have a
feeling this might be contentious.

Doesn't this violate the basic tenet that you should not use server
side state when you don't have to?  There is no reason for instance
when someone is submitting a news group posting to bind an empty
posting in a closure and store it on the server, thereby breaking the
application in any number of cases:

1) The session times out because the user got distracted or lost their
connection temporarily
2) The user abuses the back button
3) The server fails over (assuming there is no memory replication)
4) There is a temporary connection failure and the user reloads
5) The server is restarted

All of the above cases are recoverable with what, IMO, are properly
designed frameworks that minimize server-side state.  Those are the
things that taught us state should be stored in the client whenever
possible.

I saw a bit of a discussion distinguishing REST from human
interaction, saying human interactions are not stateless, but that
does not excuse the application being so vulnerable to breakage.

This reminds me of why I dislike many ASP applications I've used -
they always break when users don't behave well or when some kicks a
server - and users, myself included, always misbehave.  I use the back
button when I shouldn't, I leave forms half filled out when I answer
the phone, and as a frequent traveler I tend to use web applications
from places with shoddy internet.  I also don't like to lose my work
when a server fails over or is restarted.

There may be a few gains from designing things the lift way -
simplicity, security, etc - but they seem to come at too great a cost.

There maybe some solutions to this, such as serialization of this data
to the client, but I'm not sure I like any of them.

-Alex


On Mar 24, 2:46 am, "marius d." <[email protected]> wrote:
> The foo reference is captured in checkAndSave which is saved on
> LiftSession in function mapping.
>
> Br's,
> Marius
>
> On Mar 24, 10:23 am, Alex <[email protected]> wrote:
>
> > If I have this in a (not Stateful) Snippet, is the checkAndSave
> > closure saving state on the server?  Where is the reference to foo
> > saved?
>
> >   def add(form: NodeSeq) : NodeSeq = {
> >     val foo = Foo.create
> >     def checkAndSave(): Unit = foo.validate match {
> >       case Nil => foo.save ; S.notice("Started foo: " + foo.body)
> >       case xs => S.error(xs) ; S.mapSnippet("Foo.add", doBind)
> >     }
> >     def doBind(form: NodeSeq) =
> >       bind("foo", form,
> >         "body" -> foo.body.toForm,
> >         "submit" -> submit("Submit", checkAndSave))
>
> >     doBind(form)
> >   }

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