Sessions

Sessions in joy are persisted in an encrypted cookie and set with SameSite=Strict, HttpOnly and Path=/

Adding data to the session

In a given handler, how do you add data to the session? Here’s how:

(use joy)

(defn home-page [request]
  (let [name (get-in request [:session :name])]
    [:div (string "welcome to the home page " name])))

(defn add-to-session [request]
  (let [name (get-in request [:params :name])]
    (-> (redirect-to :home-page)
        (put :session {:name name}))))

(defroutes routes
  [:get "/" home-page]
  [:get "/set-name/:name" add-to-session])

(def app (-> (handler routes)
             (session)))

Here we see how to take a url parameter :name get it out of the params dictionary in request and then put it into the session. You don’t need to redirect, it’s just a convenience thing and usually you’re setting the session on a redirect not a regular 200 response.

Another way to see it is this:

(defn add-to-session [request]
  (let [name (get-in request [:params :name])]
    {:status 200 :body " " :headers @{"Location" "/"} :session {:name name}}))

Always good to see the bare data.

Removing data from the session

Likewise you can remove data from the session similarly:

(-> (redirect-to :home-page)
    (put :session {}))