[web-devel] Re: State in Yesod

Michael Snoyman michael at snoyman.com
Wed Nov 24 18:59:01 CET 2010


On Wed, Nov 24, 2010 at 6:04 PM, Dmitry Olshansky <olshanskydr at gmail.com> wrote:
> Hello all,
>
> can I save in Yesod on server-side some information between different
> requests (State)?
> I haven't found how to do this.

Yes you can, but not by using a State monad. You basically have two choices:

* Store inside the Yesod process, using something like an MVar or
TVar. This will work fine, unless you are using multiple Yesod
processes to serve requests (odds are, you aren't).

* Store state in the database.

But if you just want to store a small amount of data about the user,
you can use the session, which stores the data encrypted in a cookie.
I can give you better advice if I know what the purpose of this is.

Michael


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