Dancer2::Core::Role::SessionFactory(3) Role for session factories

VERSION

version 0.200002

DESCRIPTION

Any class that consumes this role will be able to store, create, retrieve and destroy session objects.

The default values for attributes can be overridden in your Dancer2 configuration. See ``Session-engine'' in Dancer2::Config.

ATTRIBUTES

cookie_name

The name of the cookie to create for storing the session key

Defaults to "dancer.session"

cookie_domain

The domain of the cookie to create for storing the session key. Defaults to the empty string and is unused as a result.

cookie_path

The path of the cookie to create for storing the session key. Defaults to ``/''.

cookie_duration

Default duration before session cookie expiration. If set, the Dancer2::Core::Session "expires" attribute will be set to the current time plus this duration (expression parsed by Dancer2::Core::Time).

session_duration

Duration in seconds before sessions should expire, regardless of cookie expiration. If set, then SessionFactories should use this to enforce a limit on session validity.

is_secure

Boolean flag to tell if the session cookie is secure or not.

Default is false.

is_http_only

Boolean flag to tell if the session cookie is http only.

Default is true.

INTERFACE

Following is the interface provided by this role. When specified the required methods to implement are described.

create

Create a brand new session object and store it. Returns the newly created session object.

Triggers an exception if the session is unable to be created. 

    my $session = MySessionFactory->create();

This method does not need to be implemented in the class.

generate_id

Returns a randomly-generated, guaranteed-unique string. By default, it is a 32-character, URL-safe, Base64 encoded combination of a 32 bit timestamp and a 160 bit SHA1 digest of random seed data. The timestamp ensures that session IDs are generally monotonic.

The default algorithm is not guaranteed cryptographically secure, but it's still reasonably strong for general use.

If you have installed Math::Random::ISAAC::XS and Crypt::URandom, the seed data will be generated from a cryptographically-strong random number generator.

This method is used internally by create() to set the session ID.

This method does not need to be implemented in the class unless an alternative method for session ID generation is desired.

retrieve

Return the session object corresponding to the session ID given. If none is found, triggers an exception. 

    my $session = MySessionFactory->retrieve(id => $id);

The method "_retrieve" must be implemented. It must take $id as a single argument and must return a hash reference of session data.

destroy

Purges the session object that matches the ID given. Returns the ID of the destroyed session if succeeded, triggers an exception otherwise. 

    MySessionFactory->destroy(id => $id);

The "_destroy" method must be implemented. It must take $id as a single argument and destroy the underlying data.

flush

Make sure the session object is stored in the factory's backend. This method is called to notify the backend about the change in the session object.

The Dancer application will not call flush unless the session "is_dirty" attribute is true to avoid unnecessary writes to the database when no data has been modified.

An exception is triggered if the session is unable to be updated in the backend. 

    MySessionFactory->flush(session => $session);

The "_flush" method must be implemented. It must take two arguments: the $id and a hash reference of session data.

set_cookie_header

Sets the session cookie into the response object 

    MySessionFactory->set_cookie_header(
        response  => $response,
        session   => $session,
        destroyed => undef,
    );

The "response" parameter contains a Dancer2::Core::Response object. The "session" parameter contains a Dancer2::Core::Session object.

The "destroyed" parameter is optional. If true, it indicates the session was marked destroyed by the request context. The default "set_cookie_header" method doesn't need that information, but it is included in case a SessionFactory must handle destroyed sessions differently (such as signalling to middleware).

cookie

Coerce a session object into a Dancer2::Core::Cookie object. 

    MySessionFactory->cookie(session => $session);

sessions

Return a list of all session IDs stored in the backend. Useful to create cleaning scripts, in conjunction with session's creation time.

The "_sessions" method must be implemented. It must return an array reference of session IDs (or an empty array reference).

CONFIGURATION

If there are configuration values specific to your session factory in your config.yml or environment, those will be passed to the constructor of the session factory automatically. In order to accept and store them, you need to define accessors for them. 

    engines:
      session:
        Example:
          database_connection: "some_data"

In your session factory: 

    package Dancer2::Session::Example;
    use Moo;
    with "Dancer2::Core::Role::SessionFactory";
    has database_connection => ( is => "ro" );

You need to do this for every configuration key. The ones that do not have accessors defined will just go to the void.

AUTHOR

Dancer Core Developers

COPYRIGHT AND LICENSE

This software is copyright (c) 2016 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.

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