app: render and serve proper web pages

1 files changed, 27 insertions, 0 deletions

diff --git a/app/app_sessions.py b/app/app_sessions.py
index 89521fb..7a931d5 100644
--- a/app/app_sessions.py
+++ b/app/app_sessions.py
@@ -15,6 +15,33 @@ cookie_key = environ['COOKIE_SECRET_KEY']
 SessionManager = partial(SessionMiddleware, secret_key=cookie_key)
 
 
+class FlashMessageQueue:
+    """
+    Session decorator for managing session flash messages to be displayed to
+    the user from one page to another. This suits confirmation and error
+    messages. Messages are stored in the session cookie, which is limited in
+    size to about 4kb.
+    """
+
+    def __init__(self, request: Request):
+        if 'messages' not in request.session:
+            request.session['messages'] = []
+
+        self._messages = request.session['messages']
+
+    def add(self, class_: str, message: str):
+        self._messages.append((class_, message))
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if not self._messages:
+            raise StopIteration
+
+        return self._messages.pop(0)
+
+
 class UserSession:
     """
     Session decorator for managing user login sessions.