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



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


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.

After terminating the request, a flush is made to the session object.


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.


These settings control how a session acts.


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

    setting session_name: "mydancer_session"


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.


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.


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


Look for a session with the given id, return the session object if found, undef if not.


Create a new session, return the session object.


Write the session object to the storage engine.


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 a new uniq id.


Reads the dancer.session cookie.


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