[Catalyst-dev] Another Session discussion

[Tomas Doran]

On 4 Feb 2009, at 16:55, Matt Pitts wrote:

> I started hacking on a Moose-based Session plugin that uses Roles and
> delegation to a specified $c->model for storage. My main justification
> for this work is to just get my own gears turning, so these are just
> ideas, and I'd be happy to scrap it there's already something started.

There isn't anything started other than the vague ideas discussed the  
other day on irc.

If you have _any_ code at all, please grab a commit bit and get a  
branch of Plugin::Session (even if you throw away all the code in it  
and start again) so that the code is public - as quite a lot of  
people prefer to read code than to read text, and it'll also be nice  
to capture the entire development from beginning to end in revision  
history.

> A Roles distribution:

Are you thinking of this as actually a different dist, or as part of  
the session plugin? As Session::Store::XXXX will require  
Plugin::Session, so I don't see an issue bundling it in the main  
session dist.

>
>   Catalyst::Role::Session

<snip>

>   Catalyst::Role::Session::Flash
>     - the basic methods necessary for flash functionality
>     - interface
>         requires 'flash';
>         requires 'clear_flash';
>         requires 'keep_flash';

Flash is a _bad idea_ as its not tab safe, so I'd only be supporting  
flash for backwards compatibility - I don't think there is any value  
to providing a new interface on ways to fail ;)

>   Catalyst::Role::Session::Store
>     - the basic methods necessary to implement a storage backend

<snip>

> The Main P::Session distribution:
>
>   Catalyst::Plugin::Session
>     - consumes Catalyst::Role::Session
>     - gets $self->_session_model from
> $c->model($self->_session_model_class)
>     - ensures that
> $self->_session_model->has_role('Catalyst::Role::Session::Store')
>     - delegates many functions to $self->_session_model

It would be nice to be able to use _any model_ at all for session  
storage, even one which hadn't been specifically 'sessionified' (I'm  
thinking specifically Catalyst::Model::Adaptor type models etc).

However there is nothing to stop you having a way to apply the role  
(which is just checking requirements really) to an arbitrary model...  
Worth thinking about anyway..

>   Catalyst::Model::Session::Cookie
>     - consumes Catalyst::Role::Session::Store
>
>   Catalyst::Model::Session::DBIC
>     - consumes Catalyst::Role::Session::Store
>
>   Catalyst::Model::Session::ImaginarySomething
>     - consumes Catalyst::Role::Session::Store

How do things which don't have a store (such as, for example,  
something like Catalyst::Plugin::CookiedSession) fit into this scheme?

> And that's about as far as I got, I thought I'd get opinions before  
> more
> model starts coming about of my head. BTW, none of this actually works
> yet, it's just conceptualize code.

Good call.

Maybe worth taking a round of feedback and then writing 'the plan' up  
in some text format in subversion so that anyone interested can check  
back on (and again, we have versioned history with comments as the  
plan evolves in the face of trying to actually implement it).

> Oh, and I'm not even thinking about
> compat right now.

Totally fair. Plan the new thing, get a prototype up to prove the  
'plan' works, _then_ start thinking about how compat fits into the  
picture before everything is finalised..

Good stuff, and well volunteered - its nice to see session getting  
the redesign it needs / deserves.

Cheers
t0m