As in the Play Framework, Wisdom makes a distinction between the session and flash scope. If you have to keep data across multiple HTTP requests, you can save them in the Session or the Flash scope. Data stored in the Session is available during the whole user session, and data stored in the flash scope is only available to the next request.

It’s important to understand that Session and Flash data are not stored in the server but are added to each subsequent HTTP Request, using Cookies. This means that the data size is very limited (up to 4 KB) and that you can only store string values.

Cookies are signed with a secret key so the client can’t modify the cookie data (or it will be invalidated). The Wisdom session is not intended to be used as a cache. If you need to cache some data related to a specific session, you can use the Wisdom Cache Service and use the session to store a unique ID to associate the cached data with a specific user.

There is no technical timeout for the session, which expires when the user closes the web browser. If you need a functional timeout for a specific application, just store a timestamp into the user Session and use it however your application needs (e.g. for a maximum session duration, maximum inactivity duration, etc.).

You can retrieve the incoming Session from the HTTP request:

As the Session is just a Cookie, it is also just an HTTP header, but Wisdom provides a helper method to store a session value:

The same way, you can remove any value from the incoming session:

If you want to discard the whole session, there is special operation:

The Flash scope works exactly like the Session, but with two differences:

Here are a few examples using the Flash scope: