Provided by: libcgi-application-plugin-session-perl_1.05-2_all 
NAME
CGI::Application::Plugin::Session - Plugin that adds session support to CGI::Application
VERSION
version 1.05
SYNOPSIS
use CGI::Application::Plugin::Session;
my $language = $self->session->param('language');
DESCRIPTION
CGI::Application::Plugin::Session seamlessly adds session support to your CGI::Application
modules by providing a CGI::Session object that is accessible from anywhere in the
application.
Lazy loading is used to prevent expensive file system or database calls from being made if
the session is not needed during this request. In other words, the Session object is not
created until it is actually needed. Also, the Session object will act as a singleton by
always returning the same Session object for the duration of the request.
This module aims to be as simple and non obtrusive as possible. By not requiring any
changes to the inheritance tree of your modules, it can be easily added to existing
applications. Think of it as a plugin module that adds a couple of new methods directly
into the CGI::Application namespace simply by loading the module.
NAME
CGI::Application::Plugin::Session - Add CGI::Session support to CGI::Application
METHODS
session
This method will return the current CGI::Session object. The CGI::Session object is
created on the first call to this method, and any subsequent calls will return the same
object. This effectively creates a singleton session object for the duration of the
request. CGI::Session will look for a cookie or param containing the session ID, and
create a new session if none is found. If "session_config" has not been called before the
first call to "session", then it will choose some sane defaults to create the session
object.
# retrieve the session object
my $session = $self->session;
- or -
# use the session object directly
my $language = $self->session->param('language');
session_config
This method can be used to customize the functionality of the
CGI::Application::Plugin::Session module. Calling this method does not mean that a new
session object will be immediately created. The session object will not be created until
the first call to $self->session. This 'lazy loading' can prevent expensive file system
or database calls from being made if the session is not needed during this request.
The recommended place to call "session_config" is in the "cgiapp_init" stage of
CGI::Application. If this method is called after the session object has already been
accessed, then it will die with an error message.
If this method is not called at all then a reasonable set of defaults will be used (the
exact default values are defined below).
The following parameters are accepted:
CGI_SESSION_OPTIONS
This allows you to customize how the CGI::Session object is created by providing a
list of options that will be passed to the CGI::Session constructor. Please see the
documentation for CGI::Session for the exact syntax of the parameters.
DEFAULT_EXPIRY
CGI::Session Allows you to set an expiry time for the session. You can set the
DEFAULT_EXPIRY option to have a default expiry time set for all newly created
sessions. It takes the same format as the $session->expiry method of CGI::Session
takes. Note that it is only set for new session, not when a session is reloaded from
the store.
COOKIE_PARAMS
This allows you to customize the options that are used when creating the session
cookie. For example you could provide an expiry time for the cookie by passing
-expiry => '+24h'. The -name and -value parameters for the cookie will be added
automatically unless you specifically override them by providing -name and/or -value
parameters. See the CGI::Cookie docs for the exact syntax of the parameters.
NOTE: You can do the following to get both the cookie name and the internal name of
the CGI::Session object to be changed:
$self->session_config(
CGI_SESSION_OPTIONS => [
$driver,
$self->query,
\%driver_options,
{ name => 'new_cookie_name' } # change cookie and session name
]
);
Also, if '-name' parameter and 'name' of session don't match a warning will be
emitted.
SEND_COOKIE
If set to a true value, the module will automatically add a cookie header to the
outgoing headers if a new session is created (Since the session module is lazy loaded,
this will only happen if you make a call to $self->session at some point to create the
session object). This option defaults to true. If it is set to false, then no
session cookies will be sent, which may be useful if you prefer URL based sessions (it
is up to you to pass the session ID in this case).
The following example shows what options are set by default (ie this is what you would get
if you do not call session_config).
$self->session_config(
CGI_SESSION_OPTIONS => [ "driver:File", $self->query, {Directory=>'/tmp'} ],
COOKIE_PARAMS => {
-path => '/',
},
SEND_COOKIE => 1,
);
Here is a more customized example that uses the PostgreSQL driver and sets an expiry and
domain on the cookie.
$self->session_config(
CGI_SESSION_OPTIONS => [ "driver:PostgreSQL;serializer:Storable", $self->query, {Handle=>$dbh} ],
COOKIE_PARAMS => {
-domain => 'mydomain.com',
-expires => '+24h',
-path => '/',
-secure => 1,
},
);
session_cookie
This method will add a cookie to the outgoing headers containing the session ID that was
assigned by the CGI::Session module.
This method is called automatically the first time $self->session is accessed if
SEND_COOKIE was set true, which is the default, so it will most likely never need to be
called manually.
NOTE that if you do choose to call it manually that a session object will automatically be
created if it doesn't already exist. This removes the lazy loading benefits of the plugin
where a session is only created/loaded when it is required.
It could be useful if you want to force the cookie header to be sent out even if the
session is not used on this request, or if you want to manage the headers yourself by
turning SEND_COOKIE to false.
# Force the cookie header to be sent including some
# custom cookie parameters
$self->session_cookie(-secure => 1, -expires => '+1w');
session_loaded
This method will let you know if the session object has been loaded yet. In other words,
it lets you know if $self->session has been called.
sub cgiapp_postrun {
my $self = shift;
$self->session->flush if $self->session_loaded;;
}
session_recreate
This method will delete the existing session, and create a brand new one for you with a
new session ID. It copies over all existing parameters into the new session.
This can be useful to protect against some login attacks when storing authentication
tokens in the session. Very briefly, an attacker loads a page on your site and creates a
session, then tries to trick a victim into loading this page with the same session ID
(possibly by embedding it in a URL). Then if the victim follows the link and subsequently
logs into their account, the attacker will have a valid session ID where the session is
now logged in, and hence the attacker has access to the victims account.
sub mylogin {
my $self = shift;
if ($newly_authenticated) {
$self->session_recreate;
}
}
session_delete
This method will perform a more comprehensive clean-up of the session, calling both the
CGI::Session delete() method, but also deleting the cookie from the client, if you are
using cookies.
sub logout {
my $self = shift;
$self->session_delete;
# what now? redirect user back to the homepage?
}
EXAMPLE
In a CGI::Application module:
# configure the session once during the init stage
sub cgiapp_init {
my $self = shift;
# Configure the session
$self->session_config(
CGI_SESSION_OPTIONS => [ "driver:PostgreSQL;serializer:Storable", $self->query, {Handle=>$self->dbh} ],
DEFAULT_EXPIRY => '+1w',
COOKIE_PARAMS => {
-expires => '+24h',
-path => '/',
},
SEND_COOKIE => 1,
);
}
sub cgiapp_prerun {
my $self = shift;
# Redirect to login, if necessary
unless ( $self->session->param('~logged-in') ) {
$self->prerun_mode('login');
}
}
sub my_runmode {
my $self = shift;
# Load the template
my $template = $self->load_tmpl('my_runmode.tmpl');
# Add all the session parameters to the template
$template->param($self->session->param_hashref());
# return the template output
return $template->output;
}
TODO
• I am considering adding support for other session modules in the future, like
Apache::Session and possibly others if there is a demand.
• Possibly add some tests to make sure cookies are accepted by the client.
• Allow a callback to be executed right after a session has been created
SEE ALSO
CGI::Application, CGI::Session, perl(1)
AUTHOR
Cees Hek <ceeshek@gmail.com>
LICENSE
Copyright (C) 2004, 2005 Cees Hek <ceeshek@gmail.com>
This library is free software. You can modify and or distribute it under the same terms as
Perl itself.
AUTHOR
Cees Hek <ceeshek@gmail.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by Cees Hek.
This is free software; you can redistribute it and/or modify it under the same terms as
the Perl 5 programming language system itself.