Safe Haskell	None
Language	Haskell2010

MessageDb.Handlers

Synopsis

data HandleError
- = HandlerParseFailure ParseMessageFailure
- | HandlerNotFound
newtype Handler output = Handler {
- fromHandler :: ReaderT Message (Except HandleError) output
}
runHandler :: Handler output -> Message -> Either HandleError output
getMessage :: Handler Message
getParsedMessage :: (FromJSON payload, FromJSON metadata) => Handler (ParsedMessage payload metadata)
type Handlers output = Map MessageType (Handler output)
emptyHandlers :: Handlers output
listToHandlers :: [(MessageType, Handler output)] -> Handlers output
addHandler :: MessageType -> Handler output -> Handlers output -> Handlers output
removeHandler :: MessageType -> Handlers output -> Handlers output
handle :: Handlers output -> Message -> Either HandleError output
type ProjectionHandler state = Handler (Endo state)
projectionHandler :: forall payload metadata state. (FromJSON payload, FromJSON metadata) => (Message -> payload -> metadata -> state -> state) -> ProjectionHandler state
type ProjectionHandlers state = Handlers (Endo state)
addProjectionHandler :: forall payload metadata state. (FromJSON payload, FromJSON metadata) => MessageType -> (Message -> payload -> metadata -> state -> state) -> ProjectionHandlers state -> ProjectionHandlers state
projectionHandle :: ProjectionHandlers state -> Message -> state -> Either HandleError state
type SubscriptionHandler = Handler (IO ())
subscriptionHandler :: forall payload metadata. (FromJSON payload, FromJSON metadata) => (Message -> payload -> metadata -> IO ()) -> SubscriptionHandler
type SubscriptionHandlers = Handlers (IO ())
addSubscriptionHandler :: forall payload metadata. (FromJSON payload, FromJSON metadata) => MessageType -> (Message -> payload -> metadata -> IO ()) -> SubscriptionHandlers -> SubscriptionHandlers
subscriptionHandle :: SubscriptionHandlers -> Message -> IO (Either HandleError ())

Documentation

data HandleError Source #

An error that may occur from handling a message.

Constructors

HandlerParseFailure ParseMessageFailure
HandlerNotFound

Instances

Instances details

Eq HandleError Source #
Instance details Defined in MessageDb.Handlers Methods (==) :: HandleError -> HandleError -> Bool # (/=) :: HandleError -> HandleError -> Bool #
Show HandleError Source #
Instance details Defined in MessageDb.Handlers Methods showsPrec :: Int -> HandleError -> ShowS # show :: HandleError -> String # showList :: [HandleError] -> ShowS #
Exception HandleError Source #
Instance details Defined in MessageDb.Handlers Methods toException :: HandleError -> SomeException # fromException :: SomeException -> Maybe HandleError # displayException :: HandleError -> String #
MonadError HandleError Handler Source #
Instance details Defined in MessageDb.Handlers Methods throwError :: HandleError -> Handler a # catchError :: Handler a -> (HandleError -> Handler a) -> Handler a #

newtype Handler output Source #

Constructors

Handler
Fields fromHandler :: ReaderT Message (Except HandleError) output

Instances

Instances details

Monad Handler Source #
Instance details Defined in MessageDb.Handlers Methods (>>=) :: Handler a -> (a -> Handler b) -> Handler b # (>>) :: Handler a -> Handler b -> Handler b # return :: a -> Handler a #
Functor Handler Source #
Instance details Defined in MessageDb.Handlers Methods fmap :: (a -> b) -> Handler a -> Handler b # (<$) :: a -> Handler b -> Handler a #
Applicative Handler Source #
Instance details Defined in MessageDb.Handlers Methods pure :: a -> Handler a # (<>) :: Handler (a -> b) -> Handler a -> Handler b # liftA2 :: (a -> b -> c) -> Handler a -> Handler b -> Handler c # (>) :: Handler a -> Handler b -> Handler b # (<*) :: Handler a -> Handler b -> Handler a #
MonadReader Message Handler Source #
Instance details Defined in MessageDb.Handlers Methods ask :: Handler Message # local :: (Message -> Message) -> Handler a -> Handler a # reader :: (Message -> a) -> Handler a #
MonadError HandleError Handler Source #
Instance details Defined in MessageDb.Handlers Methods throwError :: HandleError -> Handler a # catchError :: Handler a -> (HandleError -> Handler a) -> Handler a #
Semigroup output => Semigroup (Handler output) Source #
Instance details Defined in MessageDb.Handlers Methods (<>) :: Handler output -> Handler output -> Handler output # sconcat :: NonEmpty (Handler output) -> Handler output # stimes :: Integral b => b -> Handler output -> Handler output #
Monoid output => Monoid (Handler output) Source #
Instance details Defined in MessageDb.Handlers Methods mempty :: Handler output # mappend :: Handler output -> Handler output -> Handler output # mconcat :: [Handler output] -> Handler output #

runHandler :: Handler output -> Message -> Either HandleError output Source #

getMessage :: Handler Message Source #

getParsedMessage :: (FromJSON payload, FromJSON metadata) => Handler (ParsedMessage payload metadata) Source #

type Handlers output = Map MessageType (Handler output) Source #

emptyHandlers :: Handlers output Source #

listToHandlers :: [(MessageType, Handler output)] -> Handlers output Source #

addHandler :: MessageType -> Handler output -> Handlers output -> Handlers output Source #

removeHandler :: MessageType -> Handlers output -> Handlers output Source #

handle :: Handlers output -> Message -> Either HandleError output Source #

type ProjectionHandler state = Handler (Endo state) Source #

projectionHandler :: forall payload metadata state. (FromJSON payload, FromJSON metadata) => (Message -> payload -> metadata -> state -> state) -> ProjectionHandler state Source #

type ProjectionHandlers state = Handlers (Endo state) Source #

addProjectionHandler :: forall payload metadata state. (FromJSON payload, FromJSON metadata) => MessageType -> (Message -> payload -> metadata -> state -> state) -> ProjectionHandlers state -> ProjectionHandlers state Source #

projectionHandle :: ProjectionHandlers state -> Message -> state -> Either HandleError state Source #

type SubscriptionHandler = Handler (IO ()) Source #

subscriptionHandler :: forall payload metadata. (FromJSON payload, FromJSON metadata) => (Message -> payload -> metadata -> IO ()) -> SubscriptionHandler Source #

type SubscriptionHandlers = Handlers (IO ()) Source #

addSubscriptionHandler :: forall payload metadata. (FromJSON payload, FromJSON metadata) => MessageType -> (Message -> payload -> metadata -> IO ()) -> SubscriptionHandlers -> SubscriptionHandlers Source #

subscriptionHandle :: SubscriptionHandlers -> Message -> IO (Either HandleError ()) Source #