A typesafe container for data with a lifetime nominally equivalent to the lifetime of HttpSession attributes. object MySnippetCompanion { object mySessionVar extends SessionVar[String]("hello") } The standard pattern is to create a singleton object extending SessionVar instead of creating an instance variable of a concrete SessionVar subclass. This is preferred because SessionVar will use the name of its instantiating class for part of its state maintenance mechanism. If you find it necessary to create a SessionVar subclass of which there may be more than one instance, it is necessary to override the __nameSalt() method to return a unique salt value for each instance to prevent name collisions. Note: SessionVars can be used within CometActors

param

dflt - - the default value to be returned if none was set prior to requesting a value to be returned from the container