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postgrest/src/PostgREST/ApiRequest/Payload.hs
T

139 lines
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Haskell

-- |
-- Module : PostgREST.ApiRequest.Payload
-- Description : Parser for PostgREST Request Body
--
-- This module is in charge of parsing the request body (payload)
--
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE NamedFieldPuns #-}
module PostgREST.ApiRequest.Payload
( getPayload
) where
import qualified Data.Aeson as JSON
import qualified Data.Aeson.Key as K
import qualified Data.Aeson.KeyMap as KM
import qualified Data.ByteString.Char8 as BS
import qualified Data.ByteString.Lazy as LBS
import qualified Data.Csv as CSV
import qualified Data.HashMap.Strict as HM
import qualified Data.Map.Strict as M
import qualified Data.Set as S
import qualified Data.Text.Encoding as T
import qualified Data.Vector as V
import Control.Arrow ((***))
import Data.Aeson.Types (emptyArray, emptyObject)
import Data.Either.Combinators (mapBoth)
import Network.HTTP.Types.URI (parseSimpleQuery)
import PostgREST.ApiRequest.QueryParams (QueryParams (..))
import PostgREST.ApiRequest.Types
import PostgREST.Error (ApiRequestError (..))
import PostgREST.MediaType (MediaType (..))
import PostgREST.SchemaCache.Identifiers (FieldName)
import qualified PostgREST.MediaType as MediaType
import Protolude
getPayload :: RequestBody -> MediaType -> QueryParams -> Action -> Either ApiRequestError (Maybe Payload, S.Set FieldName)
getPayload reqBody contentMediaType QueryParams{qsColumns} action = do
checkedPayload <- if shouldParsePayload then payload else Right Nothing
let cols = case (checkedPayload, columns) of
(Just ProcessedJSON{payKeys}, _) -> payKeys
(Just ProcessedUrlEncoded{payKeys}, _) -> payKeys
(Just RawJSON{}, Just cls) -> cls
_ -> S.empty
return (checkedPayload, cols)
where
payload :: Either ApiRequestError (Maybe Payload)
payload = mapBoth InvalidBody Just $ case (contentMediaType, isProc) of
(MTApplicationJSON, _) ->
if isJust columns
then Right $ RawJSON reqBody
else note "All object keys must match" . payloadAttributes reqBody
=<< if LBS.null reqBody && isProc
then Right emptyObject
else first BS.pack $
-- Drop parsing error message in favor of generic one (https://github.com/PostgREST/postgrest/issues/2344)
maybe (Left "Empty or invalid json") Right $ JSON.decode reqBody
(MTTextCSV, _) -> do
json <- csvToJson <$> first BS.pack (CSV.decodeByName reqBody)
note "All lines must have same number of fields" $ payloadAttributes (JSON.encode json) json
(MTUrlEncoded, True) ->
Right $ ProcessedUrlEncoded params (S.fromList $ fst <$> params)
(MTUrlEncoded, False) ->
let paramsMap = HM.fromList $ (identity *** JSON.String) <$> params in
Right $ ProcessedJSON (JSON.encode paramsMap) $ S.fromList (HM.keys paramsMap)
(MTTextPlain, True) -> Right $ RawPay reqBody
(MTTextXML, True) -> Right $ RawPay reqBody
(MTOctetStream, True) -> Right $ RawPay reqBody
(ct, _) -> Left $ "Content-Type not acceptable: " <> MediaType.toMime ct
shouldParsePayload = case action of
ActDb (ActRelationMut _ MutationDelete) -> False
ActDb (ActRelationMut _ _) -> True
ActDb (ActRoutine _ Inv) -> True
_ -> False
columns = case action of
ActDb (ActRelationMut _ MutationCreate) -> qsColumns
ActDb (ActRelationMut _ MutationUpdate) -> qsColumns
ActDb (ActRoutine _ Inv) -> qsColumns
_ -> Nothing
isProc = case action of
ActDb (ActRoutine _ _) -> True
_ -> False
params = (T.decodeUtf8 *** T.decodeUtf8) <$> parseSimpleQuery (LBS.toStrict reqBody)
type CsvData = V.Vector (M.Map Text LBS.ByteString)
{-|
Converts CSV like
a,b
1,hi
2,bye
into a JSON array like
[ {"a": "1", "b": "hi"}, {"a": 2, "b": "bye"} ]
The reason for its odd signature is so that it can compose
directly with CSV.decodeByName
-}
csvToJson :: (CSV.Header, CsvData) -> JSON.Value
csvToJson (_, vals) =
JSON.Array $ V.map rowToJsonObj vals
where
rowToJsonObj = JSON.Object . KM.fromMapText .
M.map (\str ->
if str == "NULL"
then JSON.Null
else JSON.String . T.decodeUtf8 $ LBS.toStrict str
)
payloadAttributes :: RequestBody -> JSON.Value -> Maybe Payload
payloadAttributes raw json =
-- Test that Array contains only Objects having the same keys
case json of
JSON.Array arr ->
case arr V.!? 0 of
Just (JSON.Object o) ->
let canonicalKeys = S.fromList $ K.toText <$> KM.keys o
areKeysUniform = all (\case
JSON.Object x -> S.fromList (K.toText <$> KM.keys x) == canonicalKeys
_ -> False) arr in
if areKeysUniform
then Just $ ProcessedJSON raw canonicalKeys
else Nothing
Just _ -> Nothing
Nothing -> Just emptyPJArray
JSON.Object o -> Just $ ProcessedJSON raw (S.fromList $ K.toText <$> KM.keys o)
-- truncate everything else to an empty array.
_ -> Just emptyPJArray
where
emptyPJArray = ProcessedJSON (JSON.encode emptyArray) S.empty