NAME

       Dancer::Session::Abstract - abstract class for session engine

SPEC

       role
           A Dancer::Session object represents a session engine and should provide anything
           needed to manipulate a session, whatever its storing engine is.

       id  The session id will be written to a cookie, by default named "dancer.session", it is
           assumed that a client must accept cookies to be able to use a session-aware Dancer
           webapp. (The cookie name can be change using the "session_name" config setting.)

       storage engine
           When the session engine is enabled, a before filter takes care to initialize the
           appropriate session engine (according to the setting "session").

           Then, the filter looks for a cookie named "dancer.session" (or whatever you've set the
           "session_name" setting to, if you've used it) in order to retrieve the current session
           object. If not found, a new session object is created and its id written to the
           cookie.

           Whenever a session call is made within a route handler, the singleton representing the
           current session object is modified.

           A flush is made to the session object after every modification unless the session
           engine overrides the "is_lazy" method to return true.

DESCRIPTION

       This virtual class describes how to build a session engine for Dancer. This is done in
       order to allow multiple session storage backends with a common interface.

       Any session engine must inherit from Dancer::Session::Abstract and implement the following
       abstract methods.

   Configuration
       These settings control how a session acts.

       session_name

       The default session name is "dancer_session". This can be set in your config file:

           setting session_name: "mydancer_session"

       session_domain

       Allows you to set the domain property on the cookie, which will override the default.
       This is useful for setting the session cookie's domain to something like ".domain.com" so
       that the same cookie will be applicable and usable across subdomains of a base domain.

       session_secure

       The user's session id is stored in a cookie.  If true, this cookie will be made "secure"
       meaning it will only be served over https.

       session_expires

       When the session should expire.  The format is either the number of seconds in the future,
       or the human readable offset from "expires" in Dancer::Cookie.

       By default, there is no expiration.

       session_is_http_only

       This setting defaults to 1 and instructs the session cookie to be created with the
       "HttpOnly" option active, meaning that JavaScript will not be able to access to its value.

   Abstract Methods
       retrieve($id)
           Look for a session with the given id, return the session object if found, undef if
           not.

       create()
           Create a new session, return the session object.

       flush()
           Write the session object to the storage engine.

       destroy()
           Remove the current session object from the storage engine.

       session_name (optional)
           Returns a string with the name of cookie used for storing the session ID.

           You should probably not override this; the user can control the cookie name using the
           "session_name" setting.

   Inherited Methods
       The following methods are not supposed to be overloaded, they are generic and should be OK
       for each session engine.

       build_id
           Build a new uniq id.

       read_session_id
           Reads the "dancer.session" cookie.

       write_session_id
           Write the current session id to the "dancer.session" cookie.

       is_lazy
           Default is false.  If true, session data will not be flushed after every modification
           and the session engine (or application) will need to ensure that a flush is called
           before the end of the request.