1 files changed, 74 insertions, 0 deletions
diff --git a/src/cookie_login.clj b/src/cookie_login.clj
new file mode 100755
index 0000000..6ac1f6c
--- /dev/null
+++ b/src/cookie_login.clj
@@ -0,0 +1,74 @@
+(ns cookie-login
+  (:use compojure))
+
+(defn clear-login-token [token-key]
+  "Creates an expiration cookie for a given cookie name."
+  (set-cookie token-key "dummy"
+              :expires "Thu, 01-Jan-1970 00:00:01 GMT"))
+
+(defn handle-request-with-login-token
+  "Validates login token, handles request, and updates cookies and session
+  repository. If token is invalid or an exception is raised while reading it, 
+  the token cookie is expired."
+  [handler request expiry token-key token-maker token-reader]
+  (if-let [session-info (token-reader (get-in request [:cookies token-key]))]
+    (let [response (handler (merge-with merge
+                                        request
+                                        {:session session-info}))
+          ; Session variable priority:
+          ; 1) variables set by handler
+          ; 2) session variables from token-reader
+          ; 3) variables from repository          
+          session-map (merge (request :session)
+                             session-info
+                             (response :session))]
+      (merge-with merge
+                  response
+                  {:session session-map}
+                  (token-maker session-info expiry)))
+    (merge (handler request)
+           (clear-login-token token-key))))
+
+; Default expiration is a week.
+(def *default-login-token-expiry* (* 1000 60 60 24 7))
+(def *default-login-token-key* :login-token)
+
+(defn with-cookie-login
+  "Middleware to support automatic cookie login. Must be placed after 
+   the with-session middleware!
+
+   Accepts five configuration options:
+   - token-key:
+        The cookie name to store the login-token under.
+        Defaults to 'login-token'.
+   - expiry:
+        The number of milliseconds a login token is valid for.
+        Defaults to one week.
+   - is-logged-in?:        
+        Function to apply to request's session map to determine whether to
+        process login token or not. If a truthy value is returned,
+        then the next handler is called.
+   - token-maker:
+        Function to generate new login token from session map and 
+        milliseconds until login token expiry.
+   - token-reader:
+        Function to generate session map from login token. Should return nil
+        if login token is invalid.
+" 
+  [handler options]
+  (let [token-key     (or (options :default-token-key) *default-login-token-key*)
+        expiry        (or (options :expiry) *default-login-token-expiry*)
+        is-logged-in? (options :is-logged-in?)
+        token-maker   (options :token-maker)
+        token-reader  (options :token-reader)]
+    (fn [request]
+      (if (or (is-logged-in? (request :session))
+              (not (get-in request [:cookies token-key])))
+        (handler request)
+        (handle-request-with-login-token
+          handler
+          request
+          expiry
+          token-key
+          token-maker
+          token-reader)))))
+\ No newline at end of file