Cookies don't work quite right in HAppS out of the box. The most common problem is that google analytics and HAppS session cookies are mutually incompatible. (There is a thread about what went wrong in the initial implementation in the happs googlegroup.)
Hopefully the underlying problems will be fixed in the next HAppS hackathon.
Meanwhile, there is a workaround in the HAppSHelpers package on hackage, which is used by happstutorial, and is built into smartserver. So cookies do work in happstutorial: I use google analytics to track visitors, along with normal HAppS session cookies. And if you use happstutorial as a template for happs apps you should be fine.
Besides the cookies used by google analytics, which are obfuscated by javascript, happstutorial
uses cookies to track session state -- the data that corresponds to the current user's session in
data AppState = AppState {
appsessions :: Sessions SessionData,
appdatastore :: Users
} deriving (Show,Read,Typeable,Data)
When you log in, a cookie is created that expires in an hour (3600 seconds). And every time a happs handler needs to check if a user is logged in (for example, when it needs to decide whether to show the logged-in-user menubar) a check is made to see if a cookie has been set.
The cookie code is in ControllerMisc.hs:
startsess' getLandingpage (RenderGlobals origRq ts _) user = do
let sd = SessionData user
key <- update \$ NewSession sd
addCookie (3600) (mkCookie "sid" (show key))
.....
getMbSessKey rq = runReaderT (readCookieValue "sid") (rqInputs rq,rqCookies rq)