NAME
   Catalyst::Plugin::Session::Store::Delegate - Delegate session storage to
   an application model object.

SYNOPSIS
           use Catalyst::Plugin::Session::Store::Delegate;

DESCRIPTION
   This store plugins makes delegating session storage to a first class
   object model easy.

THE MODEL
   The model is used to retrieve the delegate object for a given session
   ID.

   This is normally something like DBIC's resultset object.

   The model must respond to the "get_model" method or closure in the
   sesion config hash (defaults to "get_session_store_delegate").

   An object must always be returned from this method, even if it means
   autovivifying. The object may optimize and create itself lazily in the
   actual store only when ->store methods are actually called.

THE DELEGATE
   A single delegate belongs to a single session ID. It provides storage
   space for arbitrary fields.

   The delegate object must respond to method calls as per the
   "session_store_delegate_key_to_accessor" method's return values.

   Typically this means responding to $obj->$field type accessors.

   If necessary, the delegate should maintain an internal reference count
   of the stored fields, so that it can garbage collect itself when all
   fields have been deleted.

   The fields are arbitrary, and are goverend by the various session
   plugins.

   The basic keys that must be supported are:

   expires
       A timestamp indicating when the session will expire.

       If a store so chooses it may clean up session data after this
       timestamp, even without being told to delete.

   session
       The main session data hash.

       Might not be used, if only "flash" exists.

   flash
       A hash much like the main session data hash, which can be created
       and deleted multiple times per session, as required.

   The delegate must also respond to the "flush" method which is used to
   tell the store delegate that no more set/get/delete methods will be
   invoked on it.

METHODS
   session_store_delegate_key_to_accessor $key, $operation
       This method implements the various calling conventions. It accepts a
       key and an operation name ("get", "set" or "delete"), and must
       return a method (could be a string or a code reference), and an
       optional list of arguments that will be invoked on the delegate.

       The default version splits $key on the first colon, extracting the
       field name and the ID. It then returns the unaltered field name, and
       if the operation is 'delete' also provides the extra argument
       "undef". This works with accessor semantics like these:

           $obj->foo;
           $obj->foo("bar");
           $obj->foo(undef);

       To facilitate a convention like

           $obj->get_foo;
           $obj->set_foo("bar");
           $obj->delete_foo;

       or

           $obj->get("foo");
           $obj->set("foo", "bar");
           $obj->delete("foo");

       simply override this method. You may look in the source of this
       module to find commented out versions which should help you.

   session_store_delegate
       This method returns the delegate, which may be cached in $c.

   get_session_store_delegate $id
       This method should get the delegate object for a given ID. See "THE
       MODEL" for more details.

   session_store_model
       This method should return the model that will provide the delegate
       object.The default implementation will simply return "$c->model(
       $c->session_store_model_name )".

   session_store_model_name
       Returns "$c->config->{session}{model_name} || "Sessions"".

   finalize_session_delegate $delegate
       Invokes the "flush" method on the delegate. May be overridden if
       that behavior is inappropriate.

   get_session_data $key
   store_session_data $key, $value
   delete_session_data $key
       These methods translate the store API into the delegate API using
       "session_store_delegate_key_to_accessor".