Happstack.UrlDisp

Run the monad

runUrlDisp :: ServerMonad m => UrlDisp m a -> m a

Unpacks a UrlDisp into a plain old ServerMonad. Used as a top-level wrapper.

Verbose API

path :: (MonadState UrlS m, Alternative m) => String -> m ()

Filters on and consumes the next element of the url path. path "str" will match requests whose next path element is "str" Consumption of the path element backtracks on failure.

meth :: (ServerMonad m, MonadPlus m) => String -> m ()

Filters on the request method. meth "GET" will match requests made using get.

param :: (ServerMonad m, Alternative m) => (String, String) -> m ()

Filters on any parameter (via put or get). param ("cmd", "foo") will match on ?cmd=foo

takePath :: (MonadState UrlS m, Alternative m) => m String

Combinator that consumes the next element of the path and passes it as an unparsed string into the following lambda expression. h takePath \x -> output (x++"99") will match on "/12" and output "1299" Consumption of the path element backtracks on failure.

readPath :: (Read a, MonadState UrlS m, Alternative m) => m a

Matches and consumes the next element of the path if that element can be successfully read as the proper type. The parsed element is returned.

endPath :: (MonadState UrlS m, Alternative m) => m ()

Only matches if the remaining path is empty.

getInput :: (ServerMonad f, Alternative f) => String -> f String

Returns a string representation of a parameter, if available. Otherwise fails.

getInputMay :: (ServerMonad f, Alternative f) => String -> f (Maybe String)

Returns Just a string representation of a parameter, or Nothing.

Infix API

h :: ServerMonad m => m ()

A null CGI action, used to begin a string of path combinators

(|/) :: (MonadState UrlS m, Alternative m) => m a -> String -> m ()

Combinator that filters on and consumes the next element of the url path. h |/ "dir" |/ "subdir" will match "/dir/subdir". Consumtion of the path element backtracks on failure.

(|//) :: (ServerMonad m, MonadPlus m) => m a -> String -> m ()

Combinator that filters on the request method. h |// "GET" will match requests made using get.

(|?) :: (ServerMonad m, Alternative m) => m a -> (String, String) -> m ()

Combinator that filters on any parameter (via put or get). h |? ("cmd","foo") will match on ?cmd=foo

(|\) :: (Read x, MonadState UrlS m, Alternative m) => m a -> (x -> m b) -> m b

Combinator that matches and consumes the next element of the path if path element can be successfully read as the proper type and passed to the following lambda expression. h |\ \x -> output (x + (1.5::Float)) will match on "/12" and output "13.5". Consumption of the path element backtracks on failure.

(|\\) :: (MonadState UrlS m, Alternative m) => m a -> (String -> m b) -> m b

Combinator that consumes the next element of the path and passes it as an unparsed string into the following lambda expression. h |\\ \x -> output (x++"99") will match on "/12" and output "1299" Consumtion of the path element backtracks on failure.

(|.) :: (MonadState UrlS m, Alternative m) => m a -> m b -> m b

Combinator that only matches if the remaining path is empty.

data UrlS

Constructors

UrlS

Fields

pPath :: [String]

Instances

Monad m => MonadState UrlS (UrlDisp m)

(FilterMonad Response m, Monad m) => FilterMonad Response (StateT UrlS m)

Monad m => Applicative (StateT UrlS m)

ServerMonad m => ServerMonad (StateT UrlS m)

newtype UrlDisp m a

Constructors

UrlDisp

Fields

unUrlDisp :: StateT UrlS m a

Instances

MonadTrans UrlDisp

(FilterMonad Response m, Monad m) => FilterMonad Response (UrlDisp m)

Monad m => WebMonad Response (UrlDisp (ServerPartT m))

Monad m => MonadState UrlS (UrlDisp m)

Monad m => Monad (UrlDisp m)

Monad m => Functor (UrlDisp m)

MonadPlus m => MonadPlus (UrlDisp m)

Monad m => Applicative (UrlDisp m)

(Monad m, MonadPlus m, Functor m) => Alternative (UrlDisp m)

ServerMonad m => ServerMonad (UrlDisp m)

MonadIO m => MonadIO (UrlDisp m)

Lifted catch

spCatch :: Exception e => ServerPartT IO a -> (e -> ServerPartT IO a) -> ServerPartT IO a