Network.Wai.Middleware.Verbs

This module provides everything you need to route based off different HTTP verbs. The Combinators section defines the get, post and other functions you would expect in a toolset like this. Likewise, we also include tools for manually looking into the VerbListenerT object constructed from the combinators, and turning it directly into a WAI MiddlewareT.

Combinators

get :: Monad m => r -> VerbListenerT r e u m ()

For simple GET responses

getReq :: Monad m => (Request -> r) -> VerbListenerT r e u m ()

Inspect the Request object supplied by WAI

post :: (Monad m, MonadIO m) => HandleUpload e m u -> (Either (Maybe e) u -> r) -> VerbListenerT r e u m ()

For simple POST responses

postReq :: (Monad m, MonadIO m) => HandleUpload e m u -> RespondUpload e u r -> VerbListenerT r e u m ()

Inspect the Request object supplied by WAI

put :: (Monad m, MonadIO m) => HandleUpload e m u -> (Either (Maybe e) u -> r) -> VerbListenerT r e u m ()

For simple PUT responses

putReq :: (Monad m, MonadIO m) => HandleUpload e m u -> RespondUpload e u r -> VerbListenerT r e u m ()

Inspect the Request object supplied by WAI

delete :: Monad m => r -> VerbListenerT r e u m ()

For simple DELETE responses

deleteReq :: Monad m => (Request -> r) -> VerbListenerT r e u m ()

Inspect the Request object supplied by WAI

Types

newtype Verbs e u m r

A map from an HTTP verb, to a responding and uploading mechanism.

Constructors

Verbs

Fields

unVerbs :: Map Verb (ResponseSpec e u m r)

Instances

Functor (Verbs e u m)

Monoid (Verbs e u m r)

Monad m => MonadState (Verbs e u m r) (VerbListenerT r e u m)

type Verb = StdMethod

getVerb :: Request -> Verb

Fetches the HTTP verb from the WAI Request - defaults to GET.

type ResponseSpec e u m r = (HandleUpload e m u, RespondUpload e u r)

type HandleUpload e m u = Request -> ExceptT (Maybe e) m u

Given a request, either throw a possibly existent error, or create some upload result.

type RespondUpload e u r = Request -> Either (Maybe e) u -> r

Given a request and the potential result of handling an upload, return a response (usually Middleware).

supplyReq :: Request -> Map Verb (ResponseSpec e u m r) -> Map Verb (ExceptT (Maybe e) m u, Either (Maybe e) u -> r)

flip ($) for supplying a Request into the two ResponseSpec functions.

Monad Transformer

newtype VerbListenerT r e u m a

The type variables are r for the result, e for the error type throwable during uploading, u is the sucessful upload type, and m and a form the last two parts of the monad transformer.

Constructors

VerbListenerT

Fields

runVerbListenerT :: StateT (Verbs e u m r) m a

Instances

MonadTrans (VerbListenerT r e u)

Monad m => Monad (VerbListenerT r e u m)

Functor m => Functor (VerbListenerT r e u m)

Monad m => Applicative (VerbListenerT r e u m)

MonadIO m => MonadIO (VerbListenerT r e u m)

Monad m => MonadState (Verbs e u m r) (VerbListenerT r e u m)

execVerbListenerT :: Monad m => VerbListenerT r e u m a -> m (Verbs e u m r)

verbsToMiddleware :: MonadIO m => VerbListenerT (MiddlewareT m) e u m () -> MiddlewareT m

Turn a map from HTTP verbs to middleware, into a middleware.

mapVerbs :: Monad m => (a -> b) -> VerbListenerT a e u m () -> VerbListenerT b e u m ()

Utilities

lookupVerb :: Verb -> Request -> Verbs e u m r -> Maybe (ExceptT (Maybe e) m u, Either (Maybe e) u -> r)

Take a verb map and a request, and return the lookup after providing the request (for upload cases).

lookupVerbM :: Monad m => Verb -> Request -> Verbs e u m r -> m (Maybe r)

Take the monadic partial result of lookupVerb, and actually handle the upload.