<h3>Cookies</h3>
<p>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.)
<p>Hopefully the underlying problems will be fixed in the next HAppS hackathon.
<p>Meanwhile, there is a workaround in the HAppSHelpers package on hackage, which is used by happstutorial.
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 your template for happs apps you should be fine.
<p>The cookie fix is just a couple lines of code in Controller.hs:
<p>import HAppS.Server.CookieFixer
<br>controller allowStressTests = map cookieFixer \$ .....
<p>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
<br>
<br>data AppState = AppState {
<br> appsessions :: Sessions SessionData,
<br> appdatastore :: Users
<br>} deriving (Show,Read,Typeable,Data)
<p>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.
<p>The cookie code is in <a href=/projectroot/src/Misc.hs>ControllerMisc.hs</a>:
<br>
<br>startsess' getLandingpage (RenderGlobals origRq ts _) user = do
<br> let sd = SessionData user
<br> key <- update \$ NewSession sd
<br> addCookie (3600) (mkCookie "sid" (show key))
<br> .....
<br>
<br>getMbSessKey rq = runReaderT (readCookieValue "sid") (rqInputs rq,rqCookies rq)