Catalyst::Plugin::Session::Store.3pm

Langue: en

Version: 2009-10-06 (ubuntu - 24/10/10)

Section: 3 (Bibliothèques de fonctions)

NAME

Catalyst::Plugin::Session::Store - Base class for session storage drivers.

SYNOPSIS

     package Catalyst::Plugin::Session::Store::MyBackend;
     use base qw/Catalyst::Plugin::Session::Store/;
 
 

DESCRIPTION

This class doesn't actually provide any functionality, but when the "Catalyst::Plugin::Session" module sets up it will check to see that "YourApp->isa("Catalyst::Plugin::Session::Store")". When you write a session storage plugin you should subclass this module for this reason. This documentation is intended for authors of session storage plugins, not for end users.

WRITING STORE PLUGINS

All session storage plugins need to adhere to the following interface specification to work correctly:

Required Methods

get_session_data $key
store_session_data $key, $data
Retrieve or store session data by key.

$data is currently either a hash reference (for most keys) or an integer value (for expires), but all value types should be supported.

Keys are in the format "prefix:id", where "prefix" is "session", "expires", or "flash", and "id" is always the session ID. Plugins such as Catalyst::Plugin::Session::PerUser store extensions to this format, such as "user:username".

It is suggested that the store should split on the colon and store the data more efficiently - the API should remain stable, with the possible addition of new prefixes in the future.

For example, "Store::DBI" maps "expires:id" a column of "session:id" by special-casing "get_session_data" and "store_session_data" for that key format, in order to ease the implementation of "delete_expired_sessions".

The only assurance stores are requred to make is that given

     $c->store_session_data( $x, $y );
 
 

for any $x,

     $y == $c->get_session_data( $x )
 
 

will hold.

store_session_data ( $key, $data )
Store a session whose KEY is the first parameter and data is the second parameter in storage.

The second parameter is a hash reference, which should normally be serialized (and later deserialized by "get_session_data").

delete_session_data ( $key )
Delete the session whose KEY is the parameter.
delete_expired_sessions
This method is not called by any code at present, but may be called in the future, as part of a Catalyst-specific maintenance script.

If you are wrapping around a backend which manages its own auto expiry you can just give this method an empty body.

Error handling

All errors should be thrown using Catalyst::Exception. Return values are not checked, and are assumed to be OK. Missing values are not errors.

Auto-Expiry on the Backend

Storage plugins are encouraged to use "$c->session_expires", "$c->config('Plugin::Session' => { expires => $val })", or the storage of the "expires:$sessionid" key to perform more efficient expiration, but only for the key prefixes "session", "flash" and "expires".

If the backend chooses not to do so, Catalyst::Plugin::Session will detect expired sessions as they are retrieved and delete them if necessary.

Note that session store that use this approach may leak disk space, since nothing will actively delete an expired session. The "delete_expired_sessions" method is there so that regularly scheduled maintenance scripts can give your backend the opportunity to clean up.