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_delegate" 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".

AUTHORS

Yuval Kogman, "nothingmuch@woobling.org"

Tomas Doran, (t0m) "bobtfish@bobtfish.net" (current maintainer)