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Diffstat (limited to 'users/Profpatsch/htmx-experiment/src/Multipart.hs')
| -rw-r--r-- | users/Profpatsch/htmx-experiment/src/Multipart.hs | 227 |
1 files changed, 0 insertions, 227 deletions
diff --git a/users/Profpatsch/htmx-experiment/src/Multipart.hs b/users/Profpatsch/htmx-experiment/src/Multipart.hs deleted file mode 100644 index 59650887c633..000000000000 --- a/users/Profpatsch/htmx-experiment/src/Multipart.hs +++ /dev/null @@ -1,227 +0,0 @@ -{-# LANGUAGE QuasiQuotes #-} - -module Multipart where - -import Conduit (ConduitT, MonadResource) -import Conduit qualified as Cond -import Control.Monad.Logger (MonadLogger) -import Control.Selective (Selective) -import Data.ByteString qualified as ByteString -import Data.DList (DList) -import Data.DList qualified as DList -import Data.Functor.Compose -import Data.List qualified as List -import FieldParser -import Label -import PossehlAnalyticsPrelude --- TODO: Use the multipart module from wai-extra -import Servant.Multipart -import Servant.Multipart.API -import ValidationParseT - --- | A parser for a HTTP multipart form (a form sent by the browser) -newtype MultipartParseT backend m a = MultipartParseT - { unMultipartParseT :: - MultipartData backend -> - m (Validation (NonEmpty Error) a) - } - deriving - (Functor, Applicative, Selective) - via (ValidationParseT (MultipartData backend) m) - --- | After parsing a form, either we get the result or a list of form fields that failed -newtype FormValidation a - = FormValidation - (DList FormValidationResult, Maybe a) - deriving (Functor, Applicative, Selective) via (Compose ((,) (DList FormValidationResult)) Maybe) - deriving stock (Show) - -data FormValidationResult = FormValidationResult - { hasError :: Maybe Error, - formFieldName :: Text, - originalValue :: Text - } - deriving stock (Show) - -mkFormValidationResult :: - ( HasField "formFieldName" form Text, - HasField "originalValue" form Text - ) => - form -> - Maybe Error -> - FormValidationResult -mkFormValidationResult form err = - FormValidationResult - { hasError = err, - formFieldName = form.formFieldName, - originalValue = form.originalValue - } - -eitherToFormValidation :: - ( HasField "formFieldName" form Text, - HasField "originalValue" form Text - ) => - form -> - Either Error a -> - FormValidation a -eitherToFormValidation form = \case - Left err -> - FormValidation $ (DList.singleton $ mkFormValidationResult form (Just err), Nothing) - Right a -> - FormValidation $ ((DList.singleton $ mkFormValidationResult form Nothing), Just a) - -failFormValidation :: - ( HasField "formFieldName" form Text, - HasField "originalValue" form Text - ) => - form -> - Error -> - FormValidation a -failFormValidation form err = - FormValidation (DList.singleton $ mkFormValidationResult form (Just err), Nothing) - --- | Parse the multipart form or throw a user error with a descriptive error message. -parseMultipart :: - (MonadLogger m, MonadThrow m) => - MultipartParseT backend m a -> - MultipartData backend -> - m a -parseMultipart parser multipartData = - runValidationParseTOrUserError "Cannot parse the multipart form" parser multipartData - --- | Parse the field out of the multipart message -field :: Applicative m => Text -> FieldParser Text a -> MultipartParseT backend m a -field fieldName fieldParser = MultipartParseT $ \mp -> - mp.inputs - & findMaybe (\input -> if input.iName == fieldName then Just input.iValue else Nothing) - & annotate [fmt|Field "{fieldName}" does not exist in the multipart form|] - >>= runFieldParser fieldParser - & eitherToListValidation - & pure - --- | Parse the field out of the multipart message -field' :: Applicative m => Text -> FieldParser Text a -> MultipartParseT backend m (FormValidation a) -field' fieldName fieldParser = MultipartParseT $ \mp -> - mp.inputs - & findMaybe (\input -> if input.iName == fieldName then Just input.iValue else Nothing) - & annotate [fmt|Field "{fieldName}" does not exist in the multipart form|] - <&> ( \originalValue -> - originalValue - & runFieldParser fieldParser - & eitherToFormValidation - ( T2 - (label @"formFieldName" fieldName) - (label @"originalValue" originalValue) - ) - ) - & eitherToListValidation - & pure - --- | Parse the field out of the multipart message, and into a 'Label' of the given name. -fieldLabel :: forall lbl backend m a. Applicative m => Text -> FieldParser Text a -> MultipartParseT backend m (Label lbl a) -fieldLabel fieldName fieldParser = label @lbl <$> field fieldName fieldParser - --- | Parse the field out of the multipart message, and into a 'Label' of the given name. -fieldLabel' :: forall lbl backend m a. Applicative m => Text -> FieldParser Text a -> MultipartParseT backend m (FormValidation (Label lbl a)) -fieldLabel' fieldName fieldParser = fmap (label @lbl) <$> field' fieldName fieldParser - --- | parse all fields out of the multipart message, with the same parser -allFields :: Applicative m => FieldParser Input b -> MultipartParseT backend m [b] -allFields fieldParser = MultipartParseT $ \mp -> - mp.inputs - & traverseValidate (runFieldParser fieldParser) - & eitherToValidation - & pure - --- | Parse a file by name out of the multipart message -file :: - Applicative m => - Text -> - GetFileContent backend m content -> - MultipartParseT backend m (MultipartFile content) -file fieldName getContent = MultipartParseT $ \mp -> - mp.files - & List.find (\input -> input.fdInputName == fieldName) - & annotate [fmt|File "{fieldName}" does not exist in the multipart form|] - & \case - Left err -> pure $ Failure (singleton err) - Right filePath -> fileDataToMultipartFile getContent filePath <&> eitherToListValidation - --- | Return all files from the multipart message -allFiles :: - Applicative m => - GetFileContent backend m content -> - MultipartParseT backend m [MultipartFile content] -allFiles getContent = MultipartParseT $ \mp -> do - traverseValidateM (fileDataToMultipartFile getContent) mp.files - <&> eitherToValidation - --- | Ensure there is exactly one file and return it (ignoring the field name) -exactlyOneFile :: - Applicative m => - GetFileContent backend m content -> - MultipartParseT backend m (MultipartFile content) -exactlyOneFile getContent = MultipartParseT $ \mp -> - mp.files - & \case - [] -> pure $ failParse "Expected to receive a file, but the multipart form did not contain any files" - [file_] -> - file_ - & fileDataToMultipartFile getContent - <&> eitherToListValidation - more -> pure $ failParse [fmt|Expected to receive exactly one file, but the multipart form contained {List.length more} files|] - where - -- \| Fail to parse the multipart form with the given error message. - failParse :: Text -> Validation (NonEmpty Error) a - failParse = Failure . singleton . newError - -newtype GetFileContent backend m content = GetFileContent - {unGetFileContent :: (MultipartResult backend -> m (Either Error content))} - --- | Get the 'FilePath' of the temporary file on disk. --- --- __ATTN__: Must be consumed before the handler returns, otherwise the temporary file is deleted! -tmpFilePath :: Applicative m => GetFileContent Tmp m FilePath -tmpFilePath = GetFileContent $ \filePath -> pure $ Right $ filePath - -tmpFileContent :: MonadIO m => GetFileContent Tmp m ByteString -tmpFileContent = - -- \| TODO: potentially catch file reading exceptions :P - GetFileContent $ \filePath -> liftIO $ Right <$> ByteString.readFile filePath - --- | Streams the contents of the file. --- --- __ATTN__: Must be consumed before the handler returns, otherwise the temporary file is deleted! --- (Although I can’t figure out whether the handle stays open so it might not be that bad; just don’t move it to a different thread.) -tmpFileContentStream :: (MonadResource io, Applicative m) => GetFileContent Tmp m (ConduitT () ByteString io ()) -tmpFileContentStream = - -- \| TODO: potentially catch file reading exceptions :P - GetFileContent $ \filePath -> pure $ Right $ Cond.sourceFile filePath - --- | A file field in a multipart message. -data MultipartFile content = MultipartFile - { -- | @name@ attribute of the corresponding HTML @\<input\>@ - multipartNameAttribute :: Text, - -- | name of the file on the client's disk - fileNameOnDisk :: Text, - -- | MIME type for the file - fileMimeType :: Text, - -- | Content of the file - content :: content - } - --- | Convert the multipart library struct of a multipart file to our own. -fileDataToMultipartFile :: - Functor f => - GetFileContent backend f content -> - FileData backend -> - f (Either Error (MultipartFile content)) -fileDataToMultipartFile getContent file_ = runExceptT $ do - content <- ExceptT $ getContent.unGetFileContent file_.fdPayload - pure $ - MultipartFile - { multipartNameAttribute = file_.fdInputName, - fileNameOnDisk = file_.fdFileName, - fileMimeType = file_.fdFileCType, - .. - } |