Safe Haskell	None
Language	Haskell2010

Servant.API.ContentTypes

Contents

Provided Content-Types
Building your own Content-Type
NoContent
Internal

Description

A collection of basic Content-Types (also known as Internet Media Types, or MIME types). Additionally, this module provides classes that encapsulate how to serialize or deserialize values to or from a particular Content-Type.

Content-Types are used in ReqBody and the method combinators:

>>> type MyEndpoint = ReqBody '[JSON, PlainText] Book :> Get '[JSON, PlainText] Book

Meaning the endpoint accepts requests of Content-Type application/json or text/plain;charset-utf8, and returns data in either one of those formats (depending on the Accept header).

If you would like to support Content-Types beyond those provided here, then:

Declare a new data type with no constructors (e.g. data HTML).
Make an instance of it for Accept.
If you want to be able to serialize data *into* that Content-Type, make an instance of it for MimeRender.
If you want to be able to deserialize data *from* that Content-Type, make an instance of it for MimeUnrender.

Note that roles are reversed in servant-server and servant-client: to be able to serve (or even typecheck) a Get '[JSON, XML] MyData, you'll need to have the appropriate MimeRender instances in scope, whereas to query that endpoint with servant-client, you'll need a MimeUnrender instance in scope.

Synopsis

Provided Content-Types

data JSON Source #

Instances

Accept * JSON Source #	application/json
Methods contentType :: Proxy JSON ctype -> MediaType Source # contentTypes :: Proxy JSON ctype -> NonEmpty MediaType Source #
FromJSON a => MimeUnrender * JSON a Source #	`eitherDecode`
Methods mimeUnrender :: Proxy JSON a -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy JSON a -> MediaType -> ByteString -> Either String a Source #
ToJSON a => MimeRender * JSON a Source #	`encode`
Methods mimeRender :: Proxy JSON a -> a -> ByteString Source #

data PlainText Source #

Instances

Accept * PlainText Source #	text/plain;charset=utf-8
Methods contentType :: Proxy PlainText ctype -> MediaType Source # contentTypes :: Proxy PlainText ctype -> NonEmpty MediaType Source #
MimeUnrender * PlainText String Source #	Right . BC.unpack
Methods mimeUnrender :: Proxy PlainText String -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy PlainText String -> MediaType -> ByteString -> Either String a Source #
MimeUnrender * PlainText Text Source #	left show . TextS.decodeUtf8' . toStrict
Methods mimeUnrender :: Proxy PlainText Text -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy PlainText Text -> MediaType -> ByteString -> Either String a Source #
MimeUnrender * PlainText Text Source #	left show . TextL.decodeUtf8'
Methods mimeUnrender :: Proxy PlainText Text -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy PlainText Text -> MediaType -> ByteString -> Either String a Source #
MimeRender * PlainText String Source #	BC.pack
Methods mimeRender :: Proxy PlainText String -> a -> ByteString Source #
MimeRender * PlainText Text Source #	fromStrict . TextS.encodeUtf8
Methods mimeRender :: Proxy PlainText Text -> a -> ByteString Source #
MimeRender * PlainText Text Source #	`encodeUtf8`
Methods mimeRender :: Proxy PlainText Text -> a -> ByteString Source #

data FormUrlEncoded Source #

Instances

Accept * FormUrlEncoded Source #	application/x-www-form-urlencoded
Methods contentType :: Proxy FormUrlEncoded ctype -> MediaType Source # contentTypes :: Proxy FormUrlEncoded ctype -> NonEmpty MediaType Source #
FromForm a => MimeUnrender * FormUrlEncoded a Source #	`urlDecodeAsForm` Note that the `mimeUnrender p (mimeRender p x) == Right x` law only holds if every element of x is non-null (i.e., not `("", "")`)
Methods mimeUnrender :: Proxy FormUrlEncoded a -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy FormUrlEncoded a -> MediaType -> ByteString -> Either String a Source #
ToForm a => MimeRender * FormUrlEncoded a Source #	`urlEncodeAsForm` Note that the `mimeUnrender p (mimeRender p x) == Right x` law only holds if every element of x is non-null (i.e., not `("", "")`)
Methods mimeRender :: Proxy FormUrlEncoded a -> a -> ByteString Source #

data OctetStream Source #

Instances

Accept * OctetStream Source #	application/octet-stream
Methods contentType :: Proxy OctetStream ctype -> MediaType Source # contentTypes :: Proxy OctetStream ctype -> NonEmpty MediaType Source #
MimeUnrender * OctetStream ByteString Source #	Right . toStrict
Methods mimeUnrender :: Proxy OctetStream ByteString -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy OctetStream ByteString -> MediaType -> ByteString -> Either String a Source #
MimeUnrender * OctetStream ByteString Source #	Right . id
Methods mimeUnrender :: Proxy OctetStream ByteString -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy OctetStream ByteString -> MediaType -> ByteString -> Either String a Source #
MimeRender * OctetStream ByteString Source #	`fromStrict`
Methods mimeRender :: Proxy OctetStream ByteString -> a -> ByteString Source #
MimeRender * OctetStream ByteString Source #	id
Methods mimeRender :: Proxy OctetStream ByteString -> a -> ByteString Source #

Building your own Content-Type

class Accept ctype where Source #

Instances of Accept represent mimetypes. They are used for matching against the Accept HTTP header of the request, and for setting the Content-Type header of the response

Example:

>>> import Network.HTTP.Media ((//), (/:))
>>> data HTML
>>> :{
instance Accept HTML where
   contentType _ = "text" // "html" /: ("charset", "utf-8")
:}

Minimal complete definition

contentType | contentTypes

Methods

contentType :: Proxy ctype -> MediaType Source #

contentTypes :: Proxy ctype -> NonEmpty MediaType Source #

Instances

Accept * OctetStream Source #	application/octet-stream
Methods contentType :: Proxy OctetStream ctype -> MediaType Source # contentTypes :: Proxy OctetStream ctype -> NonEmpty MediaType Source #
Accept * FormUrlEncoded Source #	application/x-www-form-urlencoded
Methods contentType :: Proxy FormUrlEncoded ctype -> MediaType Source # contentTypes :: Proxy FormUrlEncoded ctype -> NonEmpty MediaType Source #
Accept * PlainText Source #	text/plain;charset=utf-8
Methods contentType :: Proxy PlainText ctype -> MediaType Source # contentTypes :: Proxy PlainText ctype -> NonEmpty MediaType Source #
Accept * JSON Source #	application/json
Methods contentType :: Proxy JSON ctype -> MediaType Source # contentTypes :: Proxy JSON ctype -> NonEmpty MediaType Source #

class Accept ctype => MimeRender ctype a where Source #

Instantiate this class to register a way of serializing a type based on the Accept header.

Example:

data MyContentType

instance Accept MyContentType where
   contentType _ = "example" // "prs.me.mine" /: ("charset", "utf-8")

instance Show a => MimeRender MyContentType a where
   mimeRender _ val = pack ("This is MINE! " ++ show val)

type MyAPI = "path" :> Get '[MyContentType] Int

Minimal complete definition

mimeRender

Methods

mimeRender :: Proxy ctype -> a -> ByteString Source #

Instances

MimeRender * OctetStream ByteString Source #	`fromStrict`
Methods mimeRender :: Proxy OctetStream ByteString -> a -> ByteString Source #
MimeRender * OctetStream ByteString Source #	id
Methods mimeRender :: Proxy OctetStream ByteString -> a -> ByteString Source #
ToForm a => MimeRender * FormUrlEncoded a Source #	`urlEncodeAsForm` Note that the `mimeUnrender p (mimeRender p x) == Right x` law only holds if every element of x is non-null (i.e., not `("", "")`)
Methods mimeRender :: Proxy FormUrlEncoded a -> a -> ByteString Source #
MimeRender * PlainText String Source #	BC.pack
Methods mimeRender :: Proxy PlainText String -> a -> ByteString Source #
MimeRender * PlainText Text Source #	fromStrict . TextS.encodeUtf8
Methods mimeRender :: Proxy PlainText Text -> a -> ByteString Source #
MimeRender * PlainText Text Source #	`encodeUtf8`
Methods mimeRender :: Proxy PlainText Text -> a -> ByteString Source #
ToJSON a => MimeRender * JSON a Source #	`encode`
Methods mimeRender :: Proxy JSON a -> a -> ByteString Source #

class Accept ctype => MimeUnrender ctype a where Source #

Instantiate this class to register a way of deserializing a type based on the request's Content-Type header.

>>> import Network.HTTP.Media hiding (Accept)
>>> import qualified Data.ByteString.Lazy.Char8 as BSC
>>> data MyContentType = MyContentType String

>>> :{
instance Accept MyContentType where
   contentType _ = "example" // "prs.me.mine" /: ("charset", "utf-8")
:}

>>> :{
instance Read a => MimeUnrender MyContentType a where
   mimeUnrender _ bs = case BSC.take 12 bs of
     "MyContentType" -> return . read . BSC.unpack $ BSC.drop 12 bs
     _ -> Left "didn't start with the magic incantation"
:}

>>> type MyAPI = "path" :> ReqBody '[MyContentType] Int :> Get '[JSON] Int

Minimal complete definition

mimeUnrender | mimeUnrenderWithType

Methods

mimeUnrender :: Proxy ctype -> ByteString -> Either String a Source #

mimeUnrenderWithType :: Proxy ctype -> MediaType -> ByteString -> Either String a Source #

Variant which is given the actual MediaType provided by the other party.

In the most cases you don't want to branch based on the MediaType. See pr552 for a motivating example.

Instances

MimeUnrender * OctetStream ByteString Source #	Right . toStrict
Methods mimeUnrender :: Proxy OctetStream ByteString -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy OctetStream ByteString -> MediaType -> ByteString -> Either String a Source #
MimeUnrender * OctetStream ByteString Source #	Right . id
Methods mimeUnrender :: Proxy OctetStream ByteString -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy OctetStream ByteString -> MediaType -> ByteString -> Either String a Source #
FromForm a => MimeUnrender * FormUrlEncoded a Source #	`urlDecodeAsForm` Note that the `mimeUnrender p (mimeRender p x) == Right x` law only holds if every element of x is non-null (i.e., not `("", "")`)
Methods mimeUnrender :: Proxy FormUrlEncoded a -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy FormUrlEncoded a -> MediaType -> ByteString -> Either String a Source #
MimeUnrender * PlainText String Source #	Right . BC.unpack
Methods mimeUnrender :: Proxy PlainText String -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy PlainText String -> MediaType -> ByteString -> Either String a Source #
MimeUnrender * PlainText Text Source #	left show . TextS.decodeUtf8' . toStrict
Methods mimeUnrender :: Proxy PlainText Text -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy PlainText Text -> MediaType -> ByteString -> Either String a Source #
MimeUnrender * PlainText Text Source #	left show . TextL.decodeUtf8'
Methods mimeUnrender :: Proxy PlainText Text -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy PlainText Text -> MediaType -> ByteString -> Either String a Source #
FromJSON a => MimeUnrender * JSON a Source #	`eitherDecode`
Methods mimeUnrender :: Proxy JSON a -> ByteString -> Either String a Source # mimeUnrenderWithType :: Proxy JSON a -> MediaType -> ByteString -> Either String a Source #

NoContent

data NoContent Source #

A type for responses without content-body.

Constructors

NoContent

Instances

Eq NoContent Source #
Methods (==) :: NoContent -> NoContent -> Bool # (/=) :: NoContent -> NoContent -> Bool #
Read NoContent Source #
Methods readsPrec :: Int -> ReadS NoContent # readList :: ReadS [NoContent] # readPrec :: ReadPrec NoContent # readListPrec :: ReadPrec [NoContent] #
Show NoContent Source #
Methods showsPrec :: Int -> NoContent -> ShowS # show :: NoContent -> String # showList :: [NoContent] -> ShowS #
Generic NoContent Source #
Associated Types type Rep NoContent :: * -> * # Methods from :: NoContent -> Rep NoContent x # to :: Rep NoContent x -> NoContent #
AllMime ((:) * ctyp ((:) * ctyp' ctyps)) => AllMimeRender ((:) * ctyp ((:) * ctyp' ctyps)) NoContent Source #
Methods allMimeRender :: Proxy [] (( ': ctyp) ((* ': ctyp') ctyps)) -> NoContent -> [(MediaType, ByteString)] Source #
Accept * ctyp => AllMimeRender ((:) * ctyp ([] *)) NoContent Source #
Methods allMimeRender :: Proxy [] (( ': ctyp) [*]) -> NoContent -> [(MediaType, ByteString)] Source #
type Rep NoContent Source #
type Rep NoContent = D1 (MetaData "NoContent" "Servant.API.ContentTypes" "servant-0.12-AQmRz3TDpVo5YDrJHpDgbE" False) (C1 (MetaCons "NoContent" PrefixI False) U1)

Internal

newtype AcceptHeader Source #

Constructors

AcceptHeader ByteString

Instances

Eq AcceptHeader Source #
Methods (==) :: AcceptHeader -> AcceptHeader -> Bool # (/=) :: AcceptHeader -> AcceptHeader -> Bool #
Read AcceptHeader Source #
Methods readsPrec :: Int -> ReadS AcceptHeader # readList :: ReadS [AcceptHeader] # readPrec :: ReadPrec AcceptHeader # readListPrec :: ReadPrec [AcceptHeader] #
Show AcceptHeader Source #
Methods showsPrec :: Int -> AcceptHeader -> ShowS # show :: AcceptHeader -> String # showList :: [AcceptHeader] -> ShowS #
Generic AcceptHeader Source #
Associated Types type Rep AcceptHeader :: * -> * # Methods from :: AcceptHeader -> Rep AcceptHeader x # to :: Rep AcceptHeader x -> AcceptHeader #
type Rep AcceptHeader Source #
type Rep AcceptHeader = D1 (MetaData "AcceptHeader" "Servant.API.ContentTypes" "servant-0.12-AQmRz3TDpVo5YDrJHpDgbE" True) (C1 (MetaCons "AcceptHeader" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 ByteString)))

class AllMime list => AllCTRender list a where Source #

Minimal complete definition

handleAcceptH

Methods

handleAcceptH :: Proxy list -> AcceptHeader -> a -> Maybe (ByteString, ByteString) Source #

Instances

TypeError Constraint (Text "No instance for (), use NoContent instead.") => AllCTRender ([] *) () Source #
Methods handleAcceptH :: Proxy [] [] -> AcceptHeader -> () -> Maybe (ByteString, ByteString) Source #
(Accept * ct, AllMime cts, AllMimeRender ((:) * ct cts) a) => AllCTRender ((:) * ct cts) a Source #
Methods handleAcceptH :: Proxy [] (( ': ct) cts) -> AcceptHeader -> a -> Maybe (ByteString, ByteString) Source #

class AllCTUnrender list a where Source #

Minimal complete definition

canHandleCTypeH

Methods

canHandleCTypeH :: Proxy list -> ByteString -> Maybe (ByteString -> Either String a) Source #

handleCTypeH :: Proxy list -> ByteString -> ByteString -> Maybe (Either String a) Source #

Instances

AllMimeUnrender ctyps a => AllCTUnrender ctyps a Source #
Methods canHandleCTypeH :: Proxy [] ctyps -> ByteString -> Maybe (ByteString -> Either String a) Source # handleCTypeH :: Proxy [] ctyps -> ByteString -> ByteString -> Maybe (Either String a) Source #

class AllMime list where Source #

Minimal complete definition

allMime

Methods

allMime :: Proxy list -> [MediaType] Source #

Instances

AllMime ([] *) Source #
Methods allMime :: Proxy [] [] -> [MediaType] Source #
(Accept * ctyp, AllMime ctyps) => AllMime ((:) * ctyp ctyps) Source #
Methods allMime :: Proxy [] (( ': ctyp) ctyps) -> [MediaType] Source #

class AllMime list => AllMimeRender list a where Source #

Minimal complete definition

allMimeRender

Methods

allMimeRender :: Proxy list -> a -> [(MediaType, ByteString)] Source #

Instances

AllMime ((:) * ctyp ((:) * ctyp' ctyps)) => AllMimeRender ((:) * ctyp ((:) * ctyp' ctyps)) NoContent Source #
Methods allMimeRender :: Proxy [] (( ': ctyp) ((* ': ctyp') ctyps)) -> NoContent -> [(MediaType, ByteString)] Source #
Accept * ctyp => AllMimeRender ((:) * ctyp ([] *)) NoContent Source #
Methods allMimeRender :: Proxy [] (( ': ctyp) [*]) -> NoContent -> [(MediaType, ByteString)] Source #
(MimeRender * ctyp a, AllMimeRender ((:) * ctyp' ctyps) a) => AllMimeRender ((:) * ctyp ((:) * ctyp' ctyps)) a Source #
Methods allMimeRender :: Proxy [] (( ': ctyp) ((* ': ctyp') ctyps)) -> a -> [(MediaType, ByteString)] Source #
MimeRender * ctyp a => AllMimeRender ((:) * ctyp ([] *)) a Source #
Methods allMimeRender :: Proxy [] (( ': ctyp) [*]) -> a -> [(MediaType, ByteString)] Source #

class AllMime list => AllMimeUnrender list a where Source #

Minimal complete definition

allMimeUnrender

Methods

allMimeUnrender :: Proxy list -> [(MediaType, ByteString -> Either String a)] Source #

Instances

AllMimeUnrender ([] *) a Source #
Methods allMimeUnrender :: Proxy [] [] -> [(MediaType, ByteString -> Either String a)] Source #
(MimeUnrender * ctyp a, AllMimeUnrender ctyps a) => AllMimeUnrender ((:) * ctyp ctyps) a Source #
Methods allMimeUnrender :: Proxy [] (( ': ctyp) ctyps) -> [(MediaType, ByteString -> Either String a)] Source #

eitherDecodeLenient :: FromJSON a => ByteString -> Either String a Source #

Like eitherDecode but allows all JSON values instead of just objects and arrays.

Will handle trailing whitespace, but not trailing junk. ie.

>>> eitherDecodeLenient "1 " :: Either String Int
Right 1

>>> eitherDecodeLenient "1 junk" :: Either String Int
Left "trailing junk after valid JSON: endOfInput"

canHandleAcceptH :: AllMime list => Proxy list -> AcceptHeader -> Bool Source #