{-# OPTIONS -F -pgmF MonadLoc #-} module TraceSample ( traceSample) where import MFlow.Wai.Blaze.Html.All hiding (page) import Control.Monad.Loc import Menu -- to run it alone, remove import menu and uncomment the following line --main= runNavigation "" $ transientNav traceSample traceSample= do page $ h2 << "Error trace example" ++> p << "MFlow now produces execution traces in case of error by making use of the backtracking mechanism" ++> p << "It is more detailed than a call stack" ++> p << "this example has a deliberate error" ++> br ++> p << "You must be logged as admin to see the trace" ++> wlink () << p << "pres here" page $ p << "Please login with admin/admin" ++> userWidget (Just "admin") userLogin u <- getCurrentUser page $ p << "The trace will appear after you press the link. press one of the options available at the bottom of the pagem" ++> p << ("user="++ u) ++> br ++> wlink () << "press here" page $ error $ "this is the error"