graphql-engine/server/src-lib/Hasura/GraphQL/Transport/HTTP/Protocol.hs

131 lines
3.8 KiB
Haskell

module Hasura.GraphQL.Transport.HTTP.Protocol
( GQLReq(..)
, GQLReqUnparsed
, GQLReqParsed
, toParsed
, GQLQueryText
, GQLExecDoc(..)
, OperationName(..)
, VariableValues
, encodeGQErr
, encodeGQResp
, GQResult(..)
, GQResponse
, isExecError
, RemoteGqlResp(..)
, GraphqlResponse(..)
, encodeGraphqlResponse
) where
import Hasura.EncJSON
import Hasura.GraphQL.Utils
import Hasura.Prelude
import Hasura.RQL.Types
import Language.GraphQL.Draft.Instances ()
import qualified Data.Aeson as J
import qualified Data.Aeson.Casing as J
import qualified Data.Aeson.TH as J
import qualified Data.ByteString.Lazy as BL
import qualified Data.HashMap.Strict as Map
import qualified Language.GraphQL.Draft.Parser as G
import qualified Language.GraphQL.Draft.Syntax as G
newtype GQLExecDoc
= GQLExecDoc { unGQLExecDoc :: [G.ExecutableDefinition] }
deriving (Ord, Show, Eq, Hashable)
instance J.FromJSON GQLExecDoc where
parseJSON v = (GQLExecDoc . G.getExecutableDefinitions) <$> J.parseJSON v
instance J.ToJSON GQLExecDoc where
toJSON = J.toJSON . G.ExecutableDocument . unGQLExecDoc
newtype OperationName
= OperationName { _unOperationName :: G.Name }
deriving (Ord, Show, Eq, Hashable, J.ToJSON)
instance J.FromJSON OperationName where
parseJSON v = OperationName . G.Name <$> J.parseJSON v
type VariableValues = Map.HashMap G.Variable J.Value
data GQLReq a
= GQLReq
{ _grOperationName :: !(Maybe OperationName)
, _grQuery :: !a
, _grVariables :: !(Maybe VariableValues)
} deriving (Show, Eq, Generic)
$(J.deriveJSON (J.aesonDrop 3 J.camelCase){J.omitNothingFields=True}
''GQLReq
)
instance (Hashable a) => Hashable (GQLReq a)
newtype GQLQueryText
= GQLQueryText
{ _unGQLQueryText :: Text
} deriving (Show, Eq, Ord, J.FromJSON, J.ToJSON, Hashable)
type GQLReqUnparsed = GQLReq GQLQueryText
type GQLReqParsed = GQLReq GQLExecDoc
toParsed :: (MonadError QErr m ) => GQLReqUnparsed -> m GQLReqParsed
toParsed req = case G.parseExecutableDoc gqlText of
Left _ -> withPathK "query" $ throwVE "not a valid graphql query"
Right a -> return $ req { _grQuery = GQLExecDoc $ G.getExecutableDefinitions a }
where
gqlText = _unGQLQueryText $ _grQuery req
encodeGQErr :: Bool -> QErr -> J.Value
encodeGQErr includeInternal qErr =
J.object [ "errors" J..= [encodeGQLErr includeInternal qErr]]
data GQResult a
= GQSuccess !a
| GQPreExecError ![J.Value]
| GQExecError ![J.Value]
deriving (Show, Eq, Functor, Foldable, Traversable)
type GQResponse = GQResult BL.ByteString
isExecError :: GQResult a -> Bool
isExecError = \case
GQExecError _ -> True
_ -> False
encodeGQResp :: GQResponse -> EncJSON
encodeGQResp gqResp =
encJFromAssocList $ case gqResp of
GQSuccess r -> [("data", encJFromLBS r)]
GQPreExecError e -> [("errors", encJFromJValue e)]
GQExecError e -> [("data", "null"), ("errors", encJFromJValue e)]
-- | Represents GraphQL response from a remote server
data RemoteGqlResp
= RemoteGqlResp
{ _rgqrData :: !(Maybe J.Value)
, _rgqrErrors :: !(Maybe [J.Value])
, _rgqrExtensions :: !(Maybe J.Value)
} deriving (Show, Eq)
$(J.deriveFromJSON (J.aesonDrop 5 J.camelCase) ''RemoteGqlResp)
encodeRemoteGqlResp :: RemoteGqlResp -> EncJSON
encodeRemoteGqlResp (RemoteGqlResp d e ex) =
encJFromAssocList [ ("data", encJFromJValue d)
, ("errors", encJFromJValue e)
, ("extensions", encJFromJValue ex)
]
-- | Represents a proper GraphQL response
data GraphqlResponse
= GRHasura !GQResponse
| GRRemote !RemoteGqlResp
encodeGraphqlResponse :: GraphqlResponse -> EncJSON
encodeGraphqlResponse = \case
GRHasura resp -> encodeGQResp resp
GRRemote resp -> encodeRemoteGqlResp resp