servant/servant-client/src/Servant/Common/Req.hs
Oleg Grenrus cfaa7a06be Merge pull request from phadej/client-monad-control
Add MonadBaseControl IO ClientM instance
2017-01-16 10:25:35 +02:00

274 lines
9.5 KiB
Haskell

{-# LANGUAGE CPP #-}
{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
module Servant.Common.Req where
import Prelude ()
import Prelude.Compat
import Control.Exception
import Control.Monad
import Control.Monad.Catch (MonadThrow, MonadCatch)
import Data.Foldable (toList)
#if MIN_VERSION_mtl(2,2,0)
import Control.Monad.Except (MonadError(..))
#else
import Control.Monad.Error.Class (MonadError(..))
#endif
import Control.Monad.Trans.Except
import GHC.Generics
import Control.Monad.Base (MonadBase (..))
import Control.Monad.IO.Class ()
import Control.Monad.Reader
import Control.Monad.Trans.Control (MonadBaseControl (..))
import Data.ByteString.Lazy hiding (pack, filter, map, null, elem, any)
import Data.String
import Data.String.Conversions
import Data.Proxy
import Data.Text (Text)
import Data.Text.Encoding
import Data.Typeable
import Network.HTTP.Media
import Network.HTTP.Types
import Network.HTTP.Client hiding (Proxy, path)
import qualified Network.HTTP.Types.Header as HTTP
import Network.URI hiding (path)
import Servant.API.ContentTypes
import Servant.Common.BaseUrl
import qualified Network.HTTP.Client as Client
import Web.HttpApiData
data ServantError
= FailureResponse
{ responseStatus :: Status
, responseContentType :: MediaType
, responseBody :: ByteString
}
| DecodeFailure
{ decodeError :: String
, responseContentType :: MediaType
, responseBody :: ByteString
}
| UnsupportedContentType
{ responseContentType :: MediaType
, responseBody :: ByteString
}
| InvalidContentTypeHeader
{ responseContentTypeHeader :: ByteString
, responseBody :: ByteString
}
| ConnectionError
{ connectionError :: SomeException
}
deriving (Show, Typeable)
instance Eq ServantError where
FailureResponse a b c == FailureResponse x y z =
(a, b, c) == (x, y, z)
DecodeFailure a b c == DecodeFailure x y z =
(a, b, c) == (x, y, z)
UnsupportedContentType a b == UnsupportedContentType x y =
(a, b) == (x, y)
InvalidContentTypeHeader a b == InvalidContentTypeHeader x y =
(a, b) == (x, y)
ConnectionError a == ConnectionError x =
show a == show x
_ == _ = False
instance Exception ServantError
data Req = Req
{ reqPath :: String
, qs :: QueryText
, reqBody :: Maybe (RequestBody, MediaType)
, reqAccept :: [MediaType]
, headers :: [(String, Text)]
}
defReq :: Req
defReq = Req "" [] Nothing [] []
appendToPath :: String -> Req -> Req
appendToPath p req =
req { reqPath = reqPath req ++ "/" ++ p }
appendToQueryString :: Text -- ^ param name
-> Maybe Text -- ^ param value
-> Req
-> Req
appendToQueryString pname pvalue req =
req { qs = qs req ++ [(pname, pvalue)]
}
addHeader :: ToHttpApiData a => String -> a -> Req -> Req
addHeader name val req = req { headers = headers req
++ [(name, decodeUtf8 (toHeader val))]
}
-- | Set body and media type of the request being constructed.
--
-- The body is set to the given bytestring using the 'RequestBodyLBS'
-- constructor.
--
{-# DEPRECATED setRQBody "Use setReqBodyLBS instead" #-}
setRQBody :: ByteString -> MediaType -> Req -> Req
setRQBody = setReqBodyLBS
-- | Set body and media type of the request being constructed.
--
-- The body is set to the given bytestring using the 'RequestBodyLBS'
-- constructor.
--
-- @since 0.9.2.0
--
setReqBodyLBS :: ByteString -> MediaType -> Req -> Req
setReqBodyLBS b t req = req { reqBody = Just (RequestBodyLBS b, t) }
-- | Set body and media type of the request being constructed.
--
-- @since 0.9.2.0
--
setReqBody :: RequestBody -> MediaType -> Req -> Req
setReqBody b t req = req { reqBody = Just (b, t) }
reqToRequest :: (Functor m, MonadThrow m) => Req -> BaseUrl -> m Request
reqToRequest req (BaseUrl reqScheme reqHost reqPort path) =
setheaders . setAccept . setrqb . setQS <$> parseRequest url
where url = show $ nullURI { uriScheme = case reqScheme of
Http -> "http:"
Https -> "https:"
, uriAuthority = Just $
URIAuth { uriUserInfo = ""
, uriRegName = reqHost
, uriPort = ":" ++ show reqPort
}
, uriPath = path ++ reqPath req
}
setrqb r = case reqBody req of
Nothing -> r
Just (b,t) -> r { requestBody = b
, requestHeaders = requestHeaders r
++ [(hContentType, cs . show $ t)] }
setQS = setQueryString $ queryTextToQuery (qs req)
setheaders r = r { requestHeaders = requestHeaders r
<> fmap toProperHeader (headers req) }
setAccept r = r { requestHeaders = filter ((/= "Accept") . fst) (requestHeaders r)
<> [("Accept", renderHeader $ reqAccept req)
| not . null . reqAccept $ req] }
toProperHeader (name, val) =
(fromString name, encodeUtf8 val)
#if !MIN_VERSION_http_client(0,4,30)
-- 'parseRequest' is introduced in http-client-0.4.30
-- it differs from 'parseUrl', by not throwing exceptions on non-2xx http statuses
--
-- See for implementations:
-- http://hackage.haskell.org/package/http-client-0.4.30/docs/src/Network-HTTP-Client-Request.html#parseRequest
-- http://hackage.haskell.org/package/http-client-0.5.0/docs/src/Network-HTTP-Client-Request.html#parseRequest
parseRequest :: MonadThrow m => String -> m Request
parseRequest url = liftM disableStatusCheck (parseUrl url)
where
disableStatusCheck req = req { checkStatus = \ _status _headers _cookies -> Nothing }
#endif
-- * performing requests
displayHttpRequest :: Method -> String
displayHttpRequest httpmethod = "HTTP " ++ cs httpmethod ++ " request"
data ClientEnv
= ClientEnv
{ manager :: Manager
, baseUrl :: BaseUrl
}
-- | @ClientM@ is the monad in which client functions run. Contains the
-- 'Manager' and 'BaseUrl' used for requests in the reader environment.
newtype ClientM a = ClientM { runClientM' :: ReaderT ClientEnv (ExceptT ServantError IO) a }
deriving ( Functor, Applicative, Monad, MonadIO, Generic
, MonadReader ClientEnv
, MonadError ServantError
, MonadThrow, MonadCatch
)
instance MonadBase IO ClientM where
liftBase = ClientM . liftBase
instance MonadBaseControl IO ClientM where
type StM ClientM a = Either ServantError a
-- liftBaseWith :: (RunInBase ClientM IO -> IO a) -> ClientM a
liftBaseWith f = ClientM (liftBaseWith (\g -> f (g . runClientM')))
-- restoreM :: StM ClientM a -> ClientM a
restoreM st = ClientM (restoreM st)
runClientM :: ClientM a -> ClientEnv -> IO (Either ServantError a)
runClientM cm env = runExceptT $ (flip runReaderT env) $ runClientM' cm
performRequest :: Method -> Req
-> ClientM ( Int, ByteString, MediaType
, [HTTP.Header], Response ByteString)
performRequest reqMethod req = do
m <- asks manager
reqHost <- asks baseUrl
partialRequest <- liftIO $ reqToRequest req reqHost
let request = partialRequest { Client.method = reqMethod }
eResponse <- liftIO $ catchConnectionError $ Client.httpLbs request m
case eResponse of
Left err ->
throwError . ConnectionError $ SomeException err
Right response -> do
let status = Client.responseStatus response
body = Client.responseBody response
hdrs = Client.responseHeaders response
status_code = statusCode status
ct <- case lookup "Content-Type" $ Client.responseHeaders response of
Nothing -> pure $ "application"//"octet-stream"
Just t -> case parseAccept t of
Nothing -> throwError $ InvalidContentTypeHeader (cs t) body
Just t' -> pure t'
unless (status_code >= 200 && status_code < 300) $
throwError $ FailureResponse status ct body
return (status_code, body, ct, hdrs, response)
performRequestCT :: MimeUnrender ct result => Proxy ct -> Method -> Req
-> ClientM ([HTTP.Header], result)
performRequestCT ct reqMethod req = do
let acceptCTS = contentTypes ct
(_status, respBody, respCT, hdrs, _response) <-
performRequest reqMethod (req { reqAccept = toList acceptCTS })
unless (any (matches respCT) acceptCTS) $ throwError $ UnsupportedContentType respCT respBody
case mimeUnrender ct respBody of
Left err -> throwError $ DecodeFailure err respCT respBody
Right val -> return (hdrs, val)
performRequestNoBody :: Method -> Req -> ClientM [HTTP.Header]
performRequestNoBody reqMethod req = do
(_status, _body, _ct, hdrs, _response) <- performRequest reqMethod req
return hdrs
catchConnectionError :: IO a -> IO (Either ServantError a)
catchConnectionError action =
catch (Right <$> action) $ \e ->
pure . Left . ConnectionError $ SomeException (e :: HttpException)