| cgi-3001.1.6.0: A library for writing CGI programs | Source code | Contents | Index
Network.CGI.Monad |
Portability | non-portable
Stability | experimental
Maintainer | bjorn@bringert.net
Contents
CGI monad class CGI monad transformer Request info Error handling
Description
Internal stuff that most people shouldn't have to use. This module mostly deals with the internals of the CGIT monad transformer.
Synopsis
class Monad m => MonadCGI m where
cgiAddHeader :: HeaderName -> String -> m ()
cgiGet :: (CGIRequest -> a) -> m a
newtype CGIT m a = CGIT {
unCGIT :: (ReaderT CGIRequest (WriterT Headers m) a)
}
type CGI a = CGIT IO a
runCGIT :: Monad m => CGIT m a -> CGIRequest -> m (Headers, a)
data CGIRequest = CGIRequest {
cgiVars :: (Map String String)
cgiInputs :: [(String, Input)]
cgiRequestBody :: ByteString
}
throwCGI :: (MonadCGI m, MonadIO m) => Exception -> m a
catchCGI :: CGI a -> (Exception -> CGI a) -> CGI a
tryCGI :: CGI a -> CGI (Either Exception a)
handleExceptionCGI :: CGI a -> (Exception -> CGI a) -> CGI a
CGI monad class
class Monad m => MonadCGI m where | Source
The class of CGI monads. Most CGI actions can be run in any monad which is an instance of this class, which means that you can use your own monad transformers to add extra functionality.
Methods
cgiAddHeader :: HeaderName -> String -> m () | Source
Add a response header.
cgiGet :: (CGIRequest -> a) -> m a | Source
Get something from the CGI request.
Instances
Monad m => MonadCGI (CGIT m)
CGI monad transformer
newtype CGIT m a | Source
The CGIT monad transformer.
Constructors
CGIT |
unCGIT :: (ReaderT CGIRequest (WriterT Headers m) a) |
Instances
MonadTrans CGIT
MonadError Exception (CGIT IO)
Monad m => Functor (CGIT m)
Monad m => Monad (CGIT m)
Monad m => MonadCGI (CGIT m)
MonadIO m => MonadIO (CGIT m)
(Typeable1 m, Typeable a) => Typeable (CGIT m a)
type CGI a = CGIT IO a | Source
A simple CGI monad with just IO.
runCGIT :: Monad m => CGIT m a -> CGIRequest -> m (Headers, a) | Source
Run a CGI action.
Request info
data CGIRequest | Source
The input to a CGI action.
Constructors
CGIRequest |
cgiVars :: (Map String String) | Environment variables.
cgiInputs :: [(String, Input)] | Input parameters. For better laziness in reading inputs, this is not a Map.
cgiRequestBody :: ByteString | Raw request body. To avoid memory leaks, this is the empty string if the request body has been interpreted as inputs in application/x-www-form-urlencoded or multipart/form-data format.
Instances
Show CGIRequest
Error handling
throwCGI :: (MonadCGI m, MonadIO m) => Exception -> m a | Source
Throw an exception in a CGI monad. The monad is required to be a `MonadIO`, so that we can use `throwIO` to guarantee ordering.
catchCGI :: CGI a -> (Exception -> CGI a) -> CGI a | Source
Catches any expection thrown by a CGI action, and uses the given exception handler if an exception is thrown.
tryCGI :: CGI a -> CGI (Either Exception a) | Source
Catches any exception thrown by an CGI action, and returns either the exception, or if no exception was raised, the result of the action.
handleExceptionCGI :: CGI a -> (Exception -> CGI a) -> CGI a | Source
Deprecated version of `catchCGI`. Use `catchCGI` instead.
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