NAME

       Dancer::Session - session engine for the Dancer framework

DESCRIPTION

       This module provides support for server-side sessions for the Dancer web framework. The
       session is accessible to the user via an abstraction layer implemented by the
       Dancer::Session class.

USAGE

   Configuration
       The session engine must be first enabled in the environment settings, this can be done
       like the following:

       In the application code:

           # enabling the YAML-file-based session engine
           set session => 'YAML';

       Or in config.yml or environments/$env.yml

           session: "YAML"

       By default sessions are disabled, you must enable them before using it. If the session
       engine is disabled, any Dancer::Session call will throw an exception.

       See "Configuration" in Dancer::Session::Abstract for more configuration options.

   Route Handlers
       When enabled, the session engine can be used in a route handler with the keyword session.
       This keyword allows you to store/retrieve values from the session by name.

       Storing a value into the session:

           session foo => 'bar';

       Retrieving that value later:

           my $foo = session 'foo';

       You can either look for an existing item in the session storage or modify one.  Here is a
       simple example of two route handlers that implement basic "/login" and "/home" actions
       using the session engine.

           post '/login' => sub {
               # look for params and authenticate the user
               # ...
               if ($user) {
                   session user_id => $user->id;
               }
           };

           get '/home' => sub {
               # if a user is present in the session, let him go, otherwise redirect to
               # /login
               if (not session('user_id')) {
                   redirect '/login';
               }
           };

       Of course, you probably don't want to have to duplicate the code to check whether the user
       is logged in for each route handler; there's an example in the Dancer::Cookbook showing
       how to use a before filter to check whether the user is logged in before all requests, and
       redirect to a login page if not.

SUPPORTED ENGINES

       Dancer has a modular session engine that makes implementing new session backends pretty
       easy. If you'd like to write your own, feel free to take a look at
       Dancer::Session::Abstract.

       The following engines are supported out-of-the-box (shipped with the core Dancer
       distribution):

       Dancer::Session::YAML
           A YAML file-based session backend, pretty convenient for development purposes, but
           maybe not the best for production needs.

       Dancer::Session::Simple
           A very simple session backend, holding all session data in memory.  This means that
           sessions are volatile, and no longer exist when the process exits.  This module is
           likely to be most useful for testing purposes, and of little use for production.

       Additionally, many more session engines are available from CPAN, including:

       Dancer::Session::Memcached
           Session are stored in Memcached servers. This is good for production matters and is a
           good way to use a fast, distributed session storage.  If you may be scaling up to add
           additional servers later, this will be a good choice.

       Dancer::Session::Cookie
           This module implements a session engine for sessions stored entirely inside encrypted
           cookies (this engine doesn't use a server-side storage).

       Dancer::Session::Storable
           This backend stores sessions on disc using Storable, which offers solid performance
           and reliable serialization of various data structures.

       Dancer::Session::MongoDB
           A backend to store sessions using MongoDB

       Dancer::Session::KiokuDB
           A backend to store sessions using KiokuDB

       Dancer::Session::PSGI
           Let Plack::Middleware::Session handle sessions; may be useful to share sessions
           between a Dancer app and other Plack-based apps.

DEPENDENCY

       Dancer::Session may depend on third-party modules, depending on the session engine used.
       See the session engine module for details.

AUTHORS

       This module has been written by Alexis Sukrieh. See the AUTHORS file that comes with this
       distribution for details.

LICENSE

       This module is free software and is released under the same terms as Perl itself.

SEE ALSO

       See Dancer for details about the complete framework.