| Safe Haskell | None |
|---|---|
| Language | Haskell98 |
Happstack.Server.Error
Description
Some useful functions if you want to wrap the ServerPartT monad transformer around the ErrorT monad transformer. e.g., ServerPartT (ErrorT e m) athrowError and catchError inside your monad.
- spUnwrapErrorT :: Monad m => (e -> ServerPartT m a) -> Request -> UnWebT (ErrorT e m) a -> UnWebT m a
- simpleErrorHandler :: Monad m => String -> ServerPartT m Response
- errorHandlerSP :: (Monad m, Error e) => (Request -> e -> WebT m a) -> ServerPartT (ErrorT e m) a -> ServerPartT m a
Documentation
spUnwrapErrorT :: Monad m => (e -> ServerPartT m a) -> Request -> UnWebT (ErrorT e m) a -> UnWebT m a Source #
Flatten ServerPartT (ErrorT e m) aServerPartT m
asimpleHTTP. Used with
mapServerPartT', e.g.,
simpleHTTP conf $ mapServerPartT' (spUnWrapErrorT simpleErrorHandler) $ myPart `catchError` errorPart
Note that in this example, simpleErrorHandler will only be run if errorPart throws an error. You can replace simpleErrorHandler with your own custom error handler.
see also: simpleErrorHandler
simpleErrorHandler :: Monad m => String -> ServerPartT m Response Source #
A simple error handler which can be used with spUnwrapErrorT.
It returns the error message as a plain text message to the browser. More sophisticated behaviour can be achieved by calling your own custom error handler instead.
see also: spUnwrapErrorT
errorHandlerSP :: (Monad m, Error e) => (Request -> e -> WebT m a) -> ServerPartT (ErrorT e m) a -> ServerPartT m a Source #
Deprecated: Use spUnwrapErrorT
This ServerPart modifier enables the use of throwError and
catchError inside the WebT actions, by adding the ErrorT
monad transformer to the stack.
You can wrap the complete second argument to simpleHTTP in this
function.
DEPRECATED: use spUnwrapErrorT instead.