NAME¶
Dancer::Session - session engine for the Dancer framework
VERSION¶
version 1.3132
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.
AUTHOR¶
Dancer Core Developers
COPYRIGHT AND LICENSE¶
This software is copyright (c) 2010 by Alexis Sukrieh.
This is free software; you can redistribute it and/or modify it under the same
terms as the Perl 5 programming language system itself.