Network.HTTP.Req

The documentation below is structured in such a way that the most important information is presented first: you learn how to do HTTP requests, how to embed them in the monad you have, and then it gives you details about less-common things you may want to know about. The documentation is written with sufficient coverage of details and examples, and it's designed to be a complete tutorial on its own.

About the library

Req is an HTTP client library that attempts to be easy-to-use, type-safe, and expandable.

“Easy-to-use” means that the library is designed to be beginner-friendly so it's simple to add to your monad stack, intuitive to work with, well-documented, and does not get in your way. Doing HTTP requests is a common task and a Haskell library for this should be approachable and clear to beginners, thus certain compromises were made. For example, one cannot currently modify ManagerSettings of the default manager because the library always uses the same implicit global manager for simplicity and maximal connection sharing. There is a way to use your own manager with different settings, but it requires more typing.

“Type-safe” means that the library tries to eliminate certain classes of errors. For example, we have correct-by-construction URLs; it is guaranteed that the user does not send the request body when using methods like GET or OPTIONS, and the amount of implicit assumptions is minimized by making the user specify their intentions in an explicit form. For example, it's not possible to avoid specifying the body or the method of a request. Authentication methods that assume HTTPS force the user to use HTTPS at the type level.

“Expandable” refers to the ability to create new components without having to resort to hacking. For example, it's possible to define your own HTTP methods, create new ways to construct the body of a request, create new authorization options, perform a request in a different way, and create your own methods to parse a response.

Using with other libraries

• You won't need the low-level interface of http-client most of the time, but when you do, it's better to do a qualified import, because http-client has naming conflicts with req.
• For streaming of large request bodies see the companion package req-conduit: https://hackage.haskell.org/package/req-conduit.

Lightweight, no risk solution

The library uses the following mature packages under the hood to guarantee you the best experience:

• https://hackage.haskell.org/package/http-client—low level HTTP client used everywhere in Haskell.
• https://hackage.haskell.org/package/http-client-tls—TLS (HTTPS) support for http-client.

It's important to note that since we leverage well-known libraries that the whole Haskell ecosystem uses, there is no risk in using req. The machinery for performing requests is the same as with http-conduit and wreq. The only difference is the API.

Making a request

To make an HTTP request you normally need only one function: req.

req

Arguments

:: (MonadHttp m, HttpMethod method, HttpBody body, HttpResponse response, HttpBodyAllowed (AllowsBody method) (ProvidesBody body))

=> method

HTTP method

-> Url scheme

Url—location of resource

-> body

Body of the request

-> Proxy response

A hint how to interpret response

-> Option scheme

Collection of optional parameters

-> m response

Response

Make an HTTP request. The function takes 5 arguments, 4 of which specify required parameters and the final Option argument is a collection of optional parameters.

Let's go through all the arguments first: req method url body response options.

method is an HTTP method such as GET or POST. The documentation has a dedicated section about HTTP methods below.

url is a Url that describes location of resource you want to interact with.

body is a body option such as NoReqBody or ReqBodyJson. The tutorial has a section about HTTP bodies, but usage is very straightforward and should be clear from the examples.

response is a type hint how to make and interpret response of an HTTP request. Out-of-the-box it can be the following:

• ignoreResponse
• jsonResponse
• bsResponse (to get a strict ByteString)
• lbsResponse (to get a lazy ByteString)

Finally, options is a Monoid that holds a composite Option for all other optional settings like query parameters, headers, non-standard port number, etc. There are quite a few things you can put there, see the corresponding section in the documentation. If you don't need anything at all, pass mempty.

Note that if you use req to do all your requests, connection sharing and reuse is done for you automatically.

See the examples below to get on the speed quickly.

Examples

First, this is a piece of boilerplate that should be in place before you try the examples:

{-# LANGUAGE DeriveGeneric     #-}
{-# LANGUAGE OverloadedStrings #-}

module Main (main) where

import Control.Monad
import Control.Monad.IO.Class
import Data.Aeson
import Data.Maybe (fromJust)
import Data.Monoid ((<>))
import Data.Text (Text)
import GHC.Generics
import Network.HTTP.Req
import qualified Data.ByteString.Char8 as B
import qualified Text.URI as URI

We will be making requests against the https://httpbin.org service.

Make a GET request, grab 5 random bytes:

main :: IO ()
main = runReq defaultHttpConfig $ do
  let n :: Int
      n = 5
  bs <- req GET (https "httpbin.org" /: "bytes" /~ n) NoReqBody bsResponse mempty
  liftIO $ B.putStrLn (responseBody bs)

The same, but now we use a query parameter named "seed" to control seed of the generator:

main :: IO ()
main = runReq defaultHttpConfig $ do
  let n, seed :: Int
      n    = 5
      seed = 100
  bs <- req GET (https "httpbin.org" /: "bytes" /~ n) NoReqBody bsResponse $
    "seed" =: seed
  liftIO $ B.putStrLn (responseBody bs)

POST JSON data and get some info about the POST request:

data MyData = MyData
  { size  :: Int
  , color :: Text
  } deriving (Show, Generic)

instance ToJSON MyData
instance FromJSON MyData

main :: IO ()
main = runReq defaultHttpConfig $ do
  let myData = MyData
        { size  = 6
        , color = "Green" }
  v <- req POST (https "httpbin.org" /: "post") (ReqBodyJson myData) jsonResponse mempty
  liftIO $ print (responseBody v :: Value)

Sending URL-encoded body:

main :: IO ()
main = runReq defaultHttpConfig $ do
  let params =
        "foo" =: ("bar" :: Text) <>
        queryFlag "baz"
  response <- req POST (https "httpbin.org" /: "post") (ReqBodyUrlEnc params) jsonResponse mempty
  liftIO $ print (responseBody response :: Value)

Using various optional parameters and URL that is not known in advance:

main :: IO ()
main = runReq defaultHttpConfig $ do
  -- This is an example of what to do when URL is given dynamically. Of
  -- course in a real application you may not want to use 'fromJust'.
  uri <- URI.mkURI "https://httpbin.org/get?foo=bar"
  let (url, options) = fromJust (useHttpsURI uri)
  response <- req GET url NoReqBody jsonResponse $
    "from" =: (15 :: Int)           <>
    "to"   =: (67 :: Int)           <>
    basicAuth "username" "password" <>
    options                         <> -- contains the ?foo=bar part
    port 443 -- here you can put any port of course
  liftIO $ print (responseBody response :: Value)

reqBr

Arguments

:: (MonadHttp m, HttpMethod method, HttpBody body, HttpBodyAllowed (AllowsBody method) (ProvidesBody body))

=> method

HTTP method

-> Url scheme

Url—location of resource

-> body

Body of the request

-> Option scheme

Collection of optional parameters

-> (Response BodyReader -> IO a)

How to consume response

-> m a

Result

A version of req that does not use one of the predefined instances of HttpResponse but instead allows the user to consume Response BodyReader manually, in a custom way.

Since: 1.0.0

reqCb

Arguments

:: (MonadHttp m, HttpMethod method, HttpBody body, HttpResponse response, HttpBodyAllowed (AllowsBody method) (ProvidesBody body))

=> method

HTTP method

-> Url scheme

Url—location of resource

-> body

Body of the request

-> Proxy response

A hint how to interpret response

-> Option scheme

Collection of optional parameters

-> (Request -> m Request)

Callback to modify the request

-> m response

Response

A version of req that takes a callback to modify the Request, but otherwise performs the request identically.

Since: 3.7.0

req'

Arguments

:: forall m method body scheme a. (MonadHttp m, HttpMethod method, HttpBody body, HttpBodyAllowed (AllowsBody method) (ProvidesBody body))

=> method

HTTP method

-> Url scheme

Url—location of resource

-> body

Body of the request

-> Option scheme

Collection of optional parameters

-> (Request -> Manager -> m a)

How to perform request

-> m a

Result

Mostly like req with respect to its arguments, but accepts a callback that allows to perform a request in arbitrary fashion.

This function does not perform handling/wrapping exceptions, checking response (with httpConfigCheckResponse), and retrying. It only prepares Request and allows you to use it.

Since: 0.3.0

withReqManager :: MonadIO m => (Manager -> m a) -> m a

Perform an action using the global implicit Manager that the rest of the library uses. This allows to reuse connections that the Manager controls.

Embedding requests in your monad

To use req in your monad, all you need to do is to make the monad an instance of the MonadHttp type class.

When writing a library, keep your API polymorphic in terms of MonadHttp, only define instance of MonadHttp in final application. Another option is to use a newtype-wrapped monad stack and define MonadHttp for it. As of the version 0.4.0, the Req monad that follows this strategy is provided out-of-the-box (see below).

class MonadIO m => MonadHttp m where

A type class for monads that support performing HTTP requests. Typically, you only need to define the handleHttpException method unless you want to tweak HttpConfig.

Minimal complete definition

handleHttpException

Methods

handleHttpException :: HttpException -> m a

This method describes how to deal with HttpException that was caught by the library. One option is to re-throw it if you are OK with exceptions, but if you prefer working with something like MonadError, this is the right place to pass it to throwError.

getHttpConfig :: m HttpConfig

Return the HttpConfig to be used when performing HTTP requests. Default implementation returns its def value, which is described in the documentation for the type. Common usage pattern with manually defined getHttpConfig is to return some hard-coded value, or a value extracted from MonadReader if a more flexible approach to configuration is desirable.

Instances

MonadHttp Req

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> Req a

getHttpConfig :: Req HttpConfig

MonadHttp m => MonadHttp (MaybeT m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> MaybeT m a

getHttpConfig :: MaybeT m HttpConfig

MonadHttp m => MonadHttp (IdentityT m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> IdentityT m a

getHttpConfig :: IdentityT m HttpConfig

MonadHttp m => MonadHttp (ExceptT e m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> ExceptT e m a

getHttpConfig :: ExceptT e m HttpConfig

(MonadHttp m, Monoid w) => MonadHttp (WriterT w m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> WriterT w m a

getHttpConfig :: WriterT w m HttpConfig

MonadHttp m => MonadHttp (StateT s m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> StateT s m a

getHttpConfig :: StateT s m HttpConfig

MonadHttp m => MonadHttp (ReaderT r m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> ReaderT r m a

getHttpConfig :: ReaderT r m HttpConfig

MonadHttp m => MonadHttp (StateT s m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> StateT s m a

getHttpConfig :: StateT s m HttpConfig

(MonadHttp m, Monoid w) => MonadHttp (WriterT w m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> WriterT w m a

getHttpConfig :: WriterT w m HttpConfig

(MonadHttp m, Monoid w) => MonadHttp (AccumT w m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> AccumT w m a

getHttpConfig :: AccumT w m HttpConfig

(MonadHttp m, Monoid w) => MonadHttp (WriterT w m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> WriterT w m a

getHttpConfig :: WriterT w m HttpConfig

MonadHttp m => MonadHttp (SelectT r m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> SelectT r m a

getHttpConfig :: SelectT r m HttpConfig

MonadHttp m => MonadHttp (ContT r m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> ContT r m a

getHttpConfig :: ContT r m HttpConfig

(MonadHttp m, Monoid w) => MonadHttp (RWST r w s m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> RWST r w s m a

getHttpConfig :: RWST r w s m HttpConfig

(MonadHttp m, Monoid w) => MonadHttp (RWST r w s m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> RWST r w s m a

getHttpConfig :: RWST r w s m HttpConfig

(MonadHttp m, Monoid w) => MonadHttp (RWST r w s m)

Since: 3.10.0

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> RWST r w s m a

getHttpConfig :: RWST r w s m HttpConfig

data HttpConfig

HttpConfig contains settings to be used when making HTTP requests.

Constructors

HttpConfig

Fields

• httpConfigProxy :: Maybe Proxy

  Proxy to use. By default values of HTTP_PROXY and HTTPS_PROXY environment variables are respected, this setting overwrites them. Default value: Nothing.

• httpConfigRedirectCount :: Int

  How many redirects to follow when getting a resource. Default value: 10.

• httpConfigAltManager :: Maybe Manager

  Alternative Manager to use. Nothing (default value) means that the default implicit manager will be used (that's what you want in 99% of cases).

• httpConfigCheckResponse :: forall b. Request -> Response b -> ByteString -> Maybe HttpExceptionContent

  Function to check the response immediately after receiving the status and headers, before streaming of response body. The third argument is the beginning of response body (typically first 1024 bytes). This is used for throwing exceptions on non-success status codes by default (set to \_ _ _ -> Nothing if this behavior is not desirable).

  When the value this function returns is Nothing, nothing will happen. When it there is HttpExceptionContent inside Just, it will be thrown.

  Throwing is better then just returning a request with non-2xx status code because in that case something is wrong and we need a way to short-cut execution (also remember that Req retries automatically on request timeouts and such, so when your request fails, it's certainly something exceptional). The thrown exception is caught by the library though and is available in handleHttpException.

  Note: signature of this function was changed in the version 1.0.0.

  Since: 0.3.0

• httpConfigRetryPolicy :: RetryPolicyM IO

  The retry policy to use for request retrying. By default def is used (see RetryPolicyM).

  Note: signature of this function was changed to disallow IO in version 1.0.0 and then changed back to its current form in 3.1.0.

  Since: 0.3.0

• httpConfigRetryJudge :: forall b. RetryStatus -> Response b -> Bool

  The function is used to decide whether to retry a request. True means that the request should be retried.

  Note: signature of this function was changed in the version 1.0.0.

  Since: 0.3.0

• httpConfigRetryJudgeException :: RetryStatus -> SomeException -> Bool

  Similar to httpConfigRetryJudge, but is used to decide when to retry requests that resulted in an exception. By default it retries on response timeout and connection timeout (changed in version 3.8.0).

  Since: 3.4.0

• httpConfigBodyPreviewLength :: forall a. Num a => a

  Max length of preview fragment of response body.

  Since: 3.6.0

defaultHttpConfig :: HttpConfig

The default value of HttpConfig.

Since: 2.0.0

data Req a

A monad that allows us to run req in any IO-enabled monad without having to define new instances.

Since: 0.4.0

Instances

Monad Req

Defined in Network.HTTP.Req

Methods

(>>=) :: Req a -> (a -> Req b) -> Req b

(>>) :: Req a -> Req b -> Req b

return :: a -> Req a

Functor Req

Defined in Network.HTTP.Req

Methods

fmap :: (a -> b) -> Req a -> Req b

(<$) :: a -> Req b -> Req a

Applicative Req

Defined in Network.HTTP.Req

Methods

pure :: a -> Req a

(<*>) :: Req (a -> b) -> Req a -> Req b

liftA2 :: (a -> b -> c) -> Req a -> Req b -> Req c

(*>) :: Req a -> Req b -> Req b

(<*) :: Req a -> Req b -> Req a

MonadIO Req

Defined in Network.HTTP.Req

Methods

liftIO :: IO a -> Req a

MonadThrow Req

Since: 3.7.0

Defined in Network.HTTP.Req

Methods

throwM :: Exception e => e -> Req a

MonadCatch Req

Since: 3.7.0

Defined in Network.HTTP.Req

Methods

catch :: Exception e => Req a -> (e -> Req a) -> Req a

MonadMask Req

Since: 3.7.0

Defined in Network.HTTP.Req

Methods

mask :: ((forall a. Req a -> Req a) -> Req b) -> Req b

uninterruptibleMask :: ((forall a. Req a -> Req a) -> Req b) -> Req b

generalBracket :: Req a -> (a -> ExitCase b -> Req c) -> (a -> Req b) -> Req (b, c)

MonadUnliftIO Req

Defined in Network.HTTP.Req

Methods

withRunInIO :: ((forall a. Req a -> IO a) -> IO b) -> Req b

MonadHttp Req

Defined in Network.HTTP.Req

Methods

handleHttpException :: HttpException -> Req a

getHttpConfig :: Req HttpConfig

MonadBase IO Req

Defined in Network.HTTP.Req

Methods

liftBase :: IO α -> Req α

MonadBaseControl IO Req

Defined in Network.HTTP.Req

Associated Types

type StM Req a

Methods

liftBaseWith :: (RunInBase Req IO -> IO a) -> Req a

restoreM :: StM Req a -> Req a

type StM Req a

Defined in Network.HTTP.Req

type StM Req a = a

runReq

Arguments

:: MonadIO m

=> HttpConfig

HttpConfig to use

-> Req a

Computation to run

-> m a

Run a computation in the Req monad with the given HttpConfig. In the case of an exceptional situation an HttpException will be thrown.

Since: 0.4.0

Request

Method

The package supports all methods as defined by RFC 2616, and PATCH which is defined by RFC 5789—that should be enough to talk to RESTful APIs. In some cases, however, you may want to add more methods (e.g. you work with WebDAV https://en.wikipedia.org/wiki/WebDAV); no need to compromise on type safety and hack, it only takes a couple of seconds to define a new method that will works seamlessly, see HttpMethod.

data GET

GET method.

Constructors

GET

Instances

HttpMethod GET

Defined in Network.HTTP.Req

Associated Types

type AllowsBody GET :: CanHaveBody

Methods

httpMethodName :: Proxy GET -> ByteString

type AllowsBody GET

Defined in Network.HTTP.Req

type AllowsBody GET = 'NoBody

data POST

POST method.

Constructors

POST

Instances

HttpMethod POST

Defined in Network.HTTP.Req

Associated Types

type AllowsBody POST :: CanHaveBody

Methods

httpMethodName :: Proxy POST -> ByteString

type AllowsBody POST

Defined in Network.HTTP.Req

type AllowsBody POST = 'CanHaveBody

data HEAD

HEAD method.

Constructors

HEAD

Instances

HttpMethod HEAD

Defined in Network.HTTP.Req

Associated Types

type AllowsBody HEAD :: CanHaveBody

Methods

httpMethodName :: Proxy HEAD -> ByteString

type AllowsBody HEAD

Defined in Network.HTTP.Req

type AllowsBody HEAD = 'NoBody

data PUT

PUT method.

Constructors

PUT

Instances

HttpMethod PUT

Defined in Network.HTTP.Req

Associated Types

type AllowsBody PUT :: CanHaveBody

Methods

httpMethodName :: Proxy PUT -> ByteString

type AllowsBody PUT

Defined in Network.HTTP.Req

type AllowsBody PUT = 'CanHaveBody

data DELETE

DELETE method. RFC 7231 allows a payload in DELETE but without semantics.

Note: before version 3.4.0 this method did not allow request bodies.

Constructors

DELETE

Instances

HttpMethod DELETE

Defined in Network.HTTP.Req

Associated Types

type AllowsBody DELETE :: CanHaveBody

Methods

httpMethodName :: Proxy DELETE -> ByteString

type AllowsBody DELETE

Defined in Network.HTTP.Req

type AllowsBody DELETE = 'CanHaveBody

data TRACE

TRACE method.

Constructors

TRACE

Instances

HttpMethod TRACE

Defined in Network.HTTP.Req

Associated Types

type AllowsBody TRACE :: CanHaveBody

Methods

httpMethodName :: Proxy TRACE -> ByteString

type AllowsBody TRACE

Defined in Network.HTTP.Req

type AllowsBody TRACE = 'CanHaveBody

data CONNECT

CONNECT method.

Constructors

CONNECT

Instances

HttpMethod CONNECT

Defined in Network.HTTP.Req

Associated Types

type AllowsBody CONNECT :: CanHaveBody

Methods

httpMethodName :: Proxy CONNECT -> ByteString

type AllowsBody CONNECT

Defined in Network.HTTP.Req

type AllowsBody CONNECT = 'CanHaveBody

data OPTIONS

OPTIONS method.

Constructors

OPTIONS

Instances

HttpMethod OPTIONS

Defined in Network.HTTP.Req

Associated Types

type AllowsBody OPTIONS :: CanHaveBody

Methods

httpMethodName :: Proxy OPTIONS -> ByteString

type AllowsBody OPTIONS

Defined in Network.HTTP.Req

type AllowsBody OPTIONS = 'NoBody

data PATCH

PATCH method.

Constructors

PATCH

Instances

HttpMethod PATCH

Defined in Network.HTTP.Req

Associated Types

type AllowsBody PATCH :: CanHaveBody

Methods

httpMethodName :: Proxy PATCH -> ByteString

type AllowsBody PATCH

Defined in Network.HTTP.Req

type AllowsBody PATCH = 'CanHaveBody

class HttpMethod a where

A type class for types that can be used as an HTTP method. To define a non-standard method, follow this example that defines COPY:

data COPY = COPY

instance HttpMethod COPY where
  type AllowsBody COPY = 'CanHaveBody
  httpMethodName Proxy = "COPY"

Associated Types

type AllowsBody a :: CanHaveBody

Type function AllowsBody returns a type of kind CanHaveBody which tells the rest of the library whether the method can have body or not. We use the special type CanHaveBody lifted to the kind level instead of Bool to get more user-friendly compiler messages.

Methods

httpMethodName :: Proxy a -> ByteString

Return name of the method as a ByteString.

Instances

HttpMethod PATCH

Defined in Network.HTTP.Req

Associated Types

type AllowsBody PATCH :: CanHaveBody

Methods

httpMethodName :: Proxy PATCH -> ByteString

HttpMethod OPTIONS

Defined in Network.HTTP.Req

Associated Types

type AllowsBody OPTIONS :: CanHaveBody

Methods

httpMethodName :: Proxy OPTIONS -> ByteString

HttpMethod CONNECT

Defined in Network.HTTP.Req

Associated Types

type AllowsBody CONNECT :: CanHaveBody

Methods

httpMethodName :: Proxy CONNECT -> ByteString

HttpMethod TRACE

Defined in Network.HTTP.Req

Associated Types

type AllowsBody TRACE :: CanHaveBody

Methods

httpMethodName :: Proxy TRACE -> ByteString

HttpMethod DELETE

Defined in Network.HTTP.Req

Associated Types

type AllowsBody DELETE :: CanHaveBody

Methods

httpMethodName :: Proxy DELETE -> ByteString

HttpMethod PUT

Defined in Network.HTTP.Req

Associated Types

type AllowsBody PUT :: CanHaveBody

Methods

httpMethodName :: Proxy PUT -> ByteString

HttpMethod HEAD

Defined in Network.HTTP.Req

Associated Types

type AllowsBody HEAD :: CanHaveBody

Methods

httpMethodName :: Proxy HEAD -> ByteString

HttpMethod POST

Defined in Network.HTTP.Req

Associated Types

type AllowsBody POST :: CanHaveBody

Methods

httpMethodName :: Proxy POST -> ByteString

HttpMethod GET

Defined in Network.HTTP.Req

Associated Types

type AllowsBody GET :: CanHaveBody

Methods

httpMethodName :: Proxy GET -> ByteString

URL

We use Urls which are correct by construction, see Url. To build a Url from a URI, use useHttpURI, useHttpsURI, or generic useURI.

data Url (scheme :: Scheme)

Request's Url. Start constructing your Url with http or https specifying the scheme and host at the same time. Then use the (/~) and (/:) operators to grow the path one piece at a time. Every single piece of path will be url(percent)-encoded, so using (/~) and (/:) is the only way to have forward slashes between path segments. This approach makes working with dynamic path segments easy and safe. See examples below how to represent various Urls (make sure the OverloadedStrings language extension is enabled).

Examples

http "httpbin.org"
-- http://httpbin.org

https "httpbin.org"
-- https://httpbin.org

https "httpbin.org" /: "encoding" /: "utf8"
-- https://httpbin.org/encoding/utf8

https "httpbin.org" /: "foo" /: "bar/baz"
-- https://httpbin.org/foo/bar%2Fbaz

https "httpbin.org" /: "bytes" /~ (10 :: Int)
-- https://httpbin.org/bytes/10

https "юникод.рф"
-- https://%D1%8E%D0%BD%D0%B8%D0%BA%D0%BE%D0%B4.%D1%80%D1%84

Instances

Typeable scheme => Lift (Url scheme :: Type)

Defined in Network.HTTP.Req

Methods

lift :: Url scheme -> Q Exp

liftTyped :: Url scheme -> Q (TExp (Url scheme))

Eq (Url scheme)

Defined in Network.HTTP.Req

Methods

(==) :: Url scheme -> Url scheme -> Bool

(/=) :: Url scheme -> Url scheme -> Bool

Typeable scheme => Data (Url scheme)

Defined in Network.HTTP.Req

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Url scheme -> c (Url scheme)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Url scheme)

toConstr :: Url scheme -> Constr

dataTypeOf :: Url scheme -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Url scheme))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Url scheme))

gmapT :: (forall b. Data b => b -> b) -> Url scheme -> Url scheme

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Url scheme -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Url scheme -> r

gmapQ :: (forall d. Data d => d -> u) -> Url scheme -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Url scheme -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Url scheme -> m (Url scheme)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Url scheme -> m (Url scheme)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Url scheme -> m (Url scheme)

Ord (Url scheme)

Defined in Network.HTTP.Req

Methods

compare :: Url scheme -> Url scheme -> Ordering

(<) :: Url scheme -> Url scheme -> Bool

(<=) :: Url scheme -> Url scheme -> Bool

(>) :: Url scheme -> Url scheme -> Bool

(>=) :: Url scheme -> Url scheme -> Bool

max :: Url scheme -> Url scheme -> Url scheme

min :: Url scheme -> Url scheme -> Url scheme

Show (Url scheme)

Defined in Network.HTTP.Req

Methods

showsPrec :: Int -> Url scheme -> ShowS

show :: Url scheme -> String

showList :: [Url scheme] -> ShowS

Generic (Url scheme)

Defined in Network.HTTP.Req

Associated Types

type Rep (Url scheme) :: Type -> Type

Methods

from :: Url scheme -> Rep (Url scheme) x

to :: Rep (Url scheme) x -> Url scheme

type Rep (Url scheme)

Defined in Network.HTTP.Req

type Rep (Url scheme) = D1 ('MetaData "Url" "Network.HTTP.Req" "req-3.13.0-Kvi8nvPJvoxGi19Xb00npT" 'False) (C1 ('MetaCons "Url" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Scheme) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (NonEmpty Text))))

http :: Text -> Url 'Http

Given host name, produce a Url which has “http” as its scheme and empty path. This also sets port to 80.

https :: Text -> Url 'Https

Given host name, produce a Url which has “https” as its scheme and empty path. This also sets port to 443.

(/~) :: ToHttpApiData a => Url scheme -> a -> Url scheme infixl 5

Grow a given Url appending a single path segment to it. Note that the path segment can be of any type that is an instance of ToHttpApiData.

(/:) :: Url scheme -> Text -> Url scheme infixl 5

A type-constrained version of (/~) to remove ambiguity in the cases when next URL piece is a Text literal.

useHttpURI :: URI -> Maybe (Url 'Http, Option scheme)

The useHttpURI function provides an alternative method to get Url (possibly with some Options) from a URI. This is useful when you are given a URL to query dynamically and don't know it beforehand.

This function expects the scheme to be “http” and host to be present.

Since: 3.0.0

useHttpsURI :: URI -> Maybe (Url 'Https, Option scheme)

Just like useHttpURI, but expects the “https” scheme.

Since: 3.0.0

useURI :: URI -> Maybe (Either (Url 'Http, Option scheme0) (Url 'Https, Option scheme1))

A combination of useHttpURI and useHttpsURI for cases when scheme is not known in advance.

Since: 3.0.0

urlQ :: QuasiQuoter

A quasiquoter to build an Url and Option tuple. The type of the generated expression is (Url scheme0, Option scheme1) with scheme0 being either Http or Https depending on the input.

Since: 3.2.0

renderUrl :: Url scheme -> Text

Render a Url as Text.

Since: 3.4.0

Body

A number of options for request bodies are available. The Content-Type header is set for you automatically according to the body option you use (it's always specified in the documentation for a given body option). To add your own way to represent request body, define an instance of HttpBody.

data NoReqBody

This data type represents empty body of an HTTP request. This is the data type to use with HttpMethods that cannot have a body, as it's the only type for which ProvidesBody returns NoBody.

Using of this body option does not set the Content-Type header.

Constructors

NoReqBody

Instances

HttpBody NoReqBody

Defined in Network.HTTP.Req

Methods

getRequestBody :: NoReqBody -> RequestBody

getRequestContentType :: NoReqBody -> Maybe ByteString

newtype ReqBodyJson a

This body option allows us to use a JSON object as the request body—probably the most popular format right now. Just wrap a data type that is an instance of ToJSON type class and you are done: it will be converted to JSON and inserted as request body.

This body option sets the Content-Type header to "application/json; charset=utf-8" value.

Constructors

ReqBodyJson a

Instances

ToJSON a => HttpBody (ReqBodyJson a)

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyJson a -> RequestBody

getRequestContentType :: ReqBodyJson a -> Maybe ByteString

newtype ReqBodyFile

This body option streams request body from a file. It is expected that the file size does not change during streaming.

Using of this body option does not set the Content-Type header.

Constructors

ReqBodyFile FilePath

Instances

HttpBody ReqBodyFile

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyFile -> RequestBody

getRequestContentType :: ReqBodyFile -> Maybe ByteString

newtype ReqBodyBs

HTTP request body represented by a strict ByteString.

Using of this body option does not set the Content-Type header.

Constructors

ReqBodyBs ByteString

Instances

HttpBody ReqBodyBs

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyBs -> RequestBody

getRequestContentType :: ReqBodyBs -> Maybe ByteString

newtype ReqBodyLbs

HTTP request body represented by a lazy ByteString.

Using of this body option does not set the Content-Type header.

Constructors

ReqBodyLbs ByteString

Instances

HttpBody ReqBodyLbs

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyLbs -> RequestBody

getRequestContentType :: ReqBodyLbs -> Maybe ByteString

newtype ReqBodyUrlEnc

URL-encoded body. This can hold a collection of parameters which are encoded similarly to query parameters at the end of query string, with the only difference that they are stored in request body. The similarity is reflected in the API as well, as you can use the same combinators you would use to add query parameters: (=:) and queryFlag.

This body option sets the Content-Type header to "application/x-www-form-urlencoded" value.

Constructors

ReqBodyUrlEnc FormUrlEncodedParam

Instances

HttpBody ReqBodyUrlEnc

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyUrlEnc -> RequestBody

getRequestContentType :: ReqBodyUrlEnc -> Maybe ByteString

data FormUrlEncodedParam

An opaque monoidal value that allows to collect URL-encoded parameters to be wrapped in ReqBodyUrlEnc.

Instances

Semigroup FormUrlEncodedParam

Defined in Network.HTTP.Req

Methods

(<>) :: FormUrlEncodedParam -> FormUrlEncodedParam -> FormUrlEncodedParam

sconcat :: NonEmpty FormUrlEncodedParam -> FormUrlEncodedParam

stimes :: Integral b => b -> FormUrlEncodedParam -> FormUrlEncodedParam

Monoid FormUrlEncodedParam

Defined in Network.HTTP.Req

Methods

mempty :: FormUrlEncodedParam

mappend :: FormUrlEncodedParam -> FormUrlEncodedParam -> FormUrlEncodedParam

mconcat :: [FormUrlEncodedParam] -> FormUrlEncodedParam

FromForm FormUrlEncodedParam

Use formToQuery.

Since: 3.11.0

Defined in Network.HTTP.Req

Methods

fromForm :: Form -> Either Text FormUrlEncodedParam

QueryParam FormUrlEncodedParam

Defined in Network.HTTP.Req

Methods

queryParam :: ToHttpApiData a => Text -> Maybe a -> FormUrlEncodedParam

queryParamToList :: FormUrlEncodedParam -> [(Text, Maybe Text)]

data ReqBodyMultipart

Multipart form data. Please consult the Network.HTTP.Client.MultipartFormData module for how to construct parts, then use reqBodyMultipart to create actual request body from the parts. reqBodyMultipart is the only way to get a value of the type ReqBodyMultipart, as its constructor is not exported on purpose.

Examples

import Control.Monad.IO.Class
import Data.Default.Class
import Network.HTTP.Req
import qualified Network.HTTP.Client.MultipartFormData as LM

main :: IO ()
main = runReq def $ do
  body <-
    reqBodyMultipart
      [ LM.partBS "title" "My Image"
      , LM.partFileSource "file1" "/tmp/image.jpg"
      ]
  response <-
    req POST (http "example.com" /: "post")
      body
      bsResponse
      mempty
  liftIO $ print (responseBody response)

Since: 0.2.0

Instances

HttpBody ReqBodyMultipart

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyMultipart -> RequestBody

getRequestContentType :: ReqBodyMultipart -> Maybe ByteString

reqBodyMultipart :: MonadIO m => [Part] -> m ReqBodyMultipart

Create ReqBodyMultipart request body from a collection of Parts.

Since: 0.2.0

class HttpBody body where

A type class for things that can be interpreted as an HTTP RequestBody.

Minimal complete definition

getRequestBody

Methods

getRequestBody :: body -> RequestBody

How to get actual RequestBody.

getRequestContentType :: body -> Maybe ByteString

This method allows us to optionally specify the value of Content-Type header that should be used with particular body option. By default it returns Nothing and so Content-Type is not set.

Instances

HttpBody ReqBodyMultipart

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyMultipart -> RequestBody

getRequestContentType :: ReqBodyMultipart -> Maybe ByteString

HttpBody ReqBodyUrlEnc

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyUrlEnc -> RequestBody

getRequestContentType :: ReqBodyUrlEnc -> Maybe ByteString

HttpBody ReqBodyLbs

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyLbs -> RequestBody

getRequestContentType :: ReqBodyLbs -> Maybe ByteString

HttpBody ReqBodyBs

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyBs -> RequestBody

getRequestContentType :: ReqBodyBs -> Maybe ByteString

HttpBody ReqBodyFile

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyFile -> RequestBody

getRequestContentType :: ReqBodyFile -> Maybe ByteString

HttpBody NoReqBody

Defined in Network.HTTP.Req

Methods

getRequestBody :: NoReqBody -> RequestBody

getRequestContentType :: NoReqBody -> Maybe ByteString

ToJSON a => HttpBody (ReqBodyJson a)

Defined in Network.HTTP.Req

Methods

getRequestBody :: ReqBodyJson a -> RequestBody

getRequestContentType :: ReqBodyJson a -> Maybe ByteString

type family ProvidesBody body :: CanHaveBody where ...

The type function recognizes NoReqBody as having NoBody, while any other body option CanHaveBody. This forces the user to use NoReqBody with GET method and other methods that should not have body.

Equations

ProvidesBody NoReqBody = 'NoBody

ProvidesBody body = 'CanHaveBody

type family HttpBodyAllowed (allowsBody :: CanHaveBody) (providesBody :: CanHaveBody) :: Constraint where ...

This type function allows any HTTP body if method says it CanHaveBody. When the method says it should have NoBody, the only body option to use is NoReqBody.

Equations

HttpBodyAllowed 'NoBody 'NoBody = ()

HttpBodyAllowed 'CanHaveBody body = ()

HttpBodyAllowed 'NoBody 'CanHaveBody = TypeError ('Text "This HTTP method does not allow attaching a request body.")

Optional parameters

Optional parameters of request include things like query parameters, headers, port number, etc. All optional parameters have the type Option, which is a Monoid. This means that you can use mempty as the last argument of req to specify no optional parameters, or combine Options using mappend or (<>) to have several of them at once.

data Option (scheme :: Scheme)

The opaque Option type is a Monoid you can use to pack collection of optional parameters like query parameters and headers. See sections below to learn which Option primitives are available.

Instances

Semigroup (Option scheme)

Defined in Network.HTTP.Req

Methods

(<>) :: Option scheme -> Option scheme -> Option scheme

sconcat :: NonEmpty (Option scheme) -> Option scheme

stimes :: Integral b => b -> Option scheme -> Option scheme

Monoid (Option scheme)

Defined in Network.HTTP.Req

Methods

mempty :: Option scheme

mappend :: Option scheme -> Option scheme -> Option scheme

mconcat :: [Option scheme] -> Option scheme

FromForm (Option scheme)

Use formToQuery.

Since: 3.11.0

Defined in Network.HTTP.Req

Methods

fromForm :: Form -> Either Text (Option scheme)

QueryParam (Option scheme)

Defined in Network.HTTP.Req

Methods

queryParam :: ToHttpApiData a => Text -> Maybe a -> Option scheme

queryParamToList :: Option scheme -> [(Text, Maybe Text)]

Query parameters

This section describes a polymorphic interface that can be used to construct query parameters (of the type Option) and form URL-encoded bodies (of the type FormUrlEncodedParam).

(=:) :: (QueryParam param, ToHttpApiData a) => Text -> a -> param infix 7

This operator builds a query parameter that will be included in URL of your request after the question sign ?. This is the same syntax you use with form URL encoded request bodies.

This operator is defined in terms of queryParam:

name =: value = queryParam name (pure value)

queryFlag :: QueryParam param => Text -> param

Construct a flag, that is, a valueless query parameter. For example, in the following URL "a" is a flag, while "b" is a query parameter with a value:

https://httpbin.org/foo/bar?a&b=10

This operator is defined in terms of queryParam:

queryFlag name = queryParam name (Nothing :: Maybe ())

formToQuery :: (QueryParam param, Monoid param, ToForm f) => f -> param

Construct query parameters from a ToForm instance. This function produces the same query params as urlEncodeAsFormStable.

Note that Form doesn't have the concept of parameters with the empty value (i.e. what you can get by key =: ""). If the value is empty, it will be encoded as a valueless parameter (i.e. what you can get by queryFlag key).

Since: 3.11.0

class QueryParam param where

A type class for query-parameter-like things. The reason to have an overloaded queryParam is to be able to use it as an Option and as a FormUrlEncodedParam when constructing form URL encoded request bodies. Having the same syntax for these cases seems natural and user-friendly.

Methods

queryParam :: ToHttpApiData a => Text -> Maybe a -> param

Create a query parameter with given name and value. If value is Nothing, it won't be included at all (i.e. you create a flag this way). It's recommended to use (=:) and queryFlag instead of this method, because they are easier to read.

queryParamToList :: param -> [(Text, Maybe Text)]

Get the query parameter names and values set by queryParam.

Since: 3.11.0

Instances

QueryParam FormUrlEncodedParam

Defined in Network.HTTP.Req

Methods

queryParam :: ToHttpApiData a => Text -> Maybe a -> FormUrlEncodedParam

queryParamToList :: FormUrlEncodedParam -> [(Text, Maybe Text)]

QueryParam (Option scheme)

Defined in Network.HTTP.Req

Methods

queryParam :: ToHttpApiData a => Text -> Maybe a -> Option scheme

queryParamToList :: Option scheme -> [(Text, Maybe Text)]

Headers

header

Arguments

:: ByteString

Header name

-> ByteString

Header value

-> Option scheme

Create an Option that adds a header. Note that if you mappend two headers with the same names the leftmost header will win. This means, in particular, that you cannot create a request with several headers of the same name.

attachHeader :: ByteString -> ByteString -> Request -> Request

Attach a header with given name and content to a Request.

Since: 1.1.0

headerRedacted :: ByteString -> ByteString -> Option scheme

Same as header, but with redacted values on print.

Since: 3.13.0

Cookies

Support for cookies is quite minimalistic at the moment. It's possible to specify which cookies to send using cookieJar and inspect Response to extract CookieJar from it (see responseCookieJar).

cookieJar :: CookieJar -> Option scheme

Use the given CookieJar. A CookieJar can be obtained from a Response record.

Authentication

This section provides the common authentication helpers in the form of Options. You should always prefer the provided authentication Options to manual construction of headers because it ensures that you only use one authentication method at a time (they overwrite each other) and provides additional type safety that prevents leaking of credentials in the cases when authentication relies on HTTPS for encrypting sensitive data.

basicAuth

Arguments

:: ByteString

Username

-> ByteString

Password

-> Option 'Https

Auth Option

The Option adds basic authentication.

See also: https://en.wikipedia.org/wiki/Basic_access_authentication.

basicAuthUnsafe

Arguments

:: ByteString

Username

-> ByteString

Password

-> Option scheme

Auth Option

An alternative to basicAuth which works for any scheme. Note that using basic access authentication without SSL/TLS is vulnerable to attacks. Use basicAuth instead unless you know what you are doing.

Since: 0.3.1

basicProxyAuth

Arguments

:: ByteString

Username

-> ByteString

Password

-> Option scheme

Auth Option

The Option set basic proxy authentication header.

Since: 1.1.0

oAuth1

Arguments

:: ByteString

Consumer token

-> ByteString

Consumer secret

-> ByteString

OAuth token

-> ByteString

OAuth token secret

-> Option scheme

Auth Option

The Option adds OAuth1 authentication.

Since: 0.2.0

oAuth2Bearer

Arguments

:: ByteString

Token

-> Option 'Https

Auth Option

The Option adds an OAuth2 bearer token. This is treated by many services as the equivalent of a username and password.

The Option is defined as:

oAuth2Bearer token = header "Authorization" ("Bearer " <> token)

See also: https://en.wikipedia.org/wiki/OAuth.

oAuth2Token

Arguments

:: ByteString

Token

-> Option 'Https

Auth Option

The Option adds a not-quite-standard OAuth2 bearer token (that seems to be used only by GitHub). This will be treated by whatever services accept it as the equivalent of a username and password.

The Option is defined as:

oAuth2Token token = header "Authorization" ("token" <> token)

See also: https://developer.github.com/v3/oauth#3-use-the-access-token-to-access-the-api.

customAuth :: (Request -> IO Request) -> Option scheme

A helper to create custom authentication Options. The given IO-enabled request transformation is applied after all other modifications when constructing a request. Use wisely.

Since: 1.1.0

Other

port :: Int -> Option scheme

Specify the port to connect to explicitly. Normally, Url you use determines the default port: 80 for HTTP and 443 for HTTPS. This Option allows us to choose an arbitrary port overwriting the defaults.

decompress

Arguments

:: (ByteString -> Bool)

Predicate that is given MIME type, it returns True when content should be decompressed on the fly.

-> Option scheme

This Option controls whether gzipped data should be decompressed on the fly. By default everything except for "application/x-tar" is decompressed, i.e. we have:

decompress (/= "application/x-tar")

You can also choose to decompress everything like this:

decompress (const True)

responseTimeout

Arguments

:: Int

Number of microseconds to wait

-> Option scheme

Specify the number of microseconds to wait for response. The default value is 30 seconds (defined in ManagerSettings of connection Manager).

httpVersion

Arguments

:: Int

Major version number

-> Int

Minor version number

-> Option scheme

HTTP version to send to the server, the default is HTTP 1.1.

Response

Response interpretations

data IgnoreResponse

Make a request and ignore the body of the response.

Instances

Show IgnoreResponse

Defined in Network.HTTP.Req

Methods

showsPrec :: Int -> IgnoreResponse -> ShowS

show :: IgnoreResponse -> String

showList :: [IgnoreResponse] -> ShowS

HttpResponse IgnoreResponse

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody IgnoreResponse

Methods

toVanillaResponse :: IgnoreResponse -> Response (HttpResponseBody IgnoreResponse)

getHttpResponse :: Response BodyReader -> IO IgnoreResponse

acceptHeader :: Proxy IgnoreResponse -> Maybe ByteString

type HttpResponseBody IgnoreResponse

Defined in Network.HTTP.Req

type HttpResponseBody IgnoreResponse = ()

ignoreResponse :: Proxy IgnoreResponse

Use this as the fourth argument of req to specify that you want it to ignore the response body.

data JsonResponse a

Make a request and interpret the body of the response as JSON. The handleHttpException method of MonadHttp instance corresponding to monad in which you use req will determine what to do in the case when parsing fails (the JsonHttpException constructor will be used).

Instances

Show a => Show (JsonResponse a)

Defined in Network.HTTP.Req

Methods

showsPrec :: Int -> JsonResponse a -> ShowS

show :: JsonResponse a -> String

showList :: [JsonResponse a] -> ShowS

FromJSON a => HttpResponse (JsonResponse a)

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody (JsonResponse a)

Methods

toVanillaResponse :: JsonResponse a -> Response (HttpResponseBody (JsonResponse a))

getHttpResponse :: Response BodyReader -> IO (JsonResponse a)

acceptHeader :: Proxy (JsonResponse a) -> Maybe ByteString

type HttpResponseBody (JsonResponse a)

Defined in Network.HTTP.Req

type HttpResponseBody (JsonResponse a) = a

jsonResponse :: Proxy (JsonResponse a)

Use this as the fourth argument of req to specify that you want it to return the JsonResponse interpretation.

data BsResponse

Make a request and interpret the body of the response as a strict ByteString.

Instances

Show BsResponse

Defined in Network.HTTP.Req

Methods

showsPrec :: Int -> BsResponse -> ShowS

show :: BsResponse -> String

showList :: [BsResponse] -> ShowS

HttpResponse BsResponse

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody BsResponse

Methods

toVanillaResponse :: BsResponse -> Response (HttpResponseBody BsResponse)

getHttpResponse :: Response BodyReader -> IO BsResponse

acceptHeader :: Proxy BsResponse -> Maybe ByteString

type HttpResponseBody BsResponse

Defined in Network.HTTP.Req

type HttpResponseBody BsResponse = ByteString

bsResponse :: Proxy BsResponse

Use this as the fourth argument of req to specify that you want to interpret the response body as a strict ByteString.

data LbsResponse

Make a request and interpret the body of the response as a lazy ByteString.

Instances

Show LbsResponse

Defined in Network.HTTP.Req

Methods

showsPrec :: Int -> LbsResponse -> ShowS

show :: LbsResponse -> String

showList :: [LbsResponse] -> ShowS

HttpResponse LbsResponse

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody LbsResponse

Methods

toVanillaResponse :: LbsResponse -> Response (HttpResponseBody LbsResponse)

getHttpResponse :: Response BodyReader -> IO LbsResponse

acceptHeader :: Proxy LbsResponse -> Maybe ByteString

type HttpResponseBody LbsResponse

Defined in Network.HTTP.Req

type HttpResponseBody LbsResponse = ByteString

lbsResponse :: Proxy LbsResponse

Use this as the fourth argument of req to specify that you want to interpret the response body as a lazy ByteString.

Inspecting a response

responseBody :: HttpResponse response => response -> HttpResponseBody response

Get the response body.

responseStatusCode :: HttpResponse response => response -> Int

Get the response status code.

responseStatusMessage :: HttpResponse response => response -> ByteString

Get the response status message.

responseHeader

Arguments

:: HttpResponse response

=> response

Response interpretation

-> ByteString

Header to lookup

-> Maybe ByteString

Header value if found

Lookup a particular header from a response.

responseCookieJar :: HttpResponse response => response -> CookieJar

Get the response CookieJar.

Defining your own interpretation

To create a new response interpretation you just need to make your data type an instance of the HttpResponse type class.

class HttpResponse response where

A type class for response interpretations. It allows us to describe how to consume the response from a Response BodyReader and produce the final result that is to be returned to the user.

Minimal complete definition

toVanillaResponse, getHttpResponse

Associated Types

type HttpResponseBody response :: Type

The associated type is the type of body that can be extracted from an instance of HttpResponse.

Methods

toVanillaResponse :: response -> Response (HttpResponseBody response)

The method describes how to get the underlying Response record.

getHttpResponse

Arguments

:: Response BodyReader

Response with body reader inside

-> IO response

The final result

This method describes how to consume response body and, more generally, obtain response value from Response BodyReader.

Note: BodyReader is nothing but IO ByteString. You should call this action repeatedly until it yields the empty ByteString. In that case streaming of response is finished (which apparently leads to closing of the connection, so don't call the reader after it has returned the empty ByteString once) and you can concatenate the chunks to obtain the final result. (Of course you could as well stream the contents to a file or do whatever you want.)

Note: signature of this function was changed in the version 1.0.0.

acceptHeader :: Proxy response -> Maybe ByteString

The value of "Accept" header. This is useful, for example, if a website supports both XML and JSON responses, and decides what to reply with based on what Accept headers you have sent.

Note: manually specified Options that set the "Accept" header will take precedence.

Since: 2.1.0

Instances

HttpResponse LbsResponse

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody LbsResponse

Methods

toVanillaResponse :: LbsResponse -> Response (HttpResponseBody LbsResponse)

getHttpResponse :: Response BodyReader -> IO LbsResponse

acceptHeader :: Proxy LbsResponse -> Maybe ByteString

HttpResponse BsResponse

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody BsResponse

Methods

toVanillaResponse :: BsResponse -> Response (HttpResponseBody BsResponse)

getHttpResponse :: Response BodyReader -> IO BsResponse

acceptHeader :: Proxy BsResponse -> Maybe ByteString

HttpResponse IgnoreResponse

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody IgnoreResponse

Methods

toVanillaResponse :: IgnoreResponse -> Response (HttpResponseBody IgnoreResponse)

getHttpResponse :: Response BodyReader -> IO IgnoreResponse

acceptHeader :: Proxy IgnoreResponse -> Maybe ByteString

HttpResponse (Response ())

This instance has been added to make it easier to inspect Response using Req's functions like responseStatusCode, responseStatusMessage, etc.

Since: 3.12.0

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody (Response ())

Methods

toVanillaResponse :: Response () -> Response (HttpResponseBody (Response ()))

getHttpResponse :: Response BodyReader -> IO (Response ())

acceptHeader :: Proxy (Response ()) -> Maybe ByteString

FromJSON a => HttpResponse (JsonResponse a)

Defined in Network.HTTP.Req

Associated Types

type HttpResponseBody (JsonResponse a)

Methods

toVanillaResponse :: JsonResponse a -> Response (HttpResponseBody (JsonResponse a))

getHttpResponse :: Response BodyReader -> IO (JsonResponse a)

acceptHeader :: Proxy (JsonResponse a) -> Maybe ByteString

Other

data HttpException

Exceptions that this library throws.

Constructors

VanillaHttpException HttpException

A wrapper with an HttpException from Network.HTTP.Client

JsonHttpException String

A wrapper with Aeson-produced String describing why decoding failed

Instances

Show HttpException

Defined in Network.HTTP.Req

Methods

showsPrec :: Int -> HttpException -> ShowS

show :: HttpException -> String

showList :: [HttpException] -> ShowS

Generic HttpException

Defined in Network.HTTP.Req

Associated Types

type Rep HttpException :: Type -> Type

Methods

from :: HttpException -> Rep HttpException x

to :: Rep HttpException x -> HttpException

Exception HttpException

Defined in Network.HTTP.Req

Methods

toException :: HttpException -> SomeException

fromException :: SomeException -> Maybe HttpException

displayException :: HttpException -> String

type Rep HttpException

Defined in Network.HTTP.Req

type Rep HttpException = D1 ('MetaData "HttpException" "Network.HTTP.Req" "req-3.13.0-Kvi8nvPJvoxGi19Xb00npT" 'False) (C1 ('MetaCons "VanillaHttpException" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 HttpException)) :+: C1 ('MetaCons "JsonHttpException" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 String)))

isStatusCodeException :: HttpException -> Maybe (Response ())

Return Just if the given HttpException is wrapping a http-client's StatusCodeException. Otherwise, return Nothing.

Since: 3.12.0

data CanHaveBody

A simple type isomorphic to Bool that we only have for better error messages. We use it as a kind and its data constructors as type-level tags.

See also: HttpMethod and HttpBody.

Constructors

CanHaveBody

Indeed can have a body

NoBody

Should not have a body

data Scheme

A type-level tag that specifies URL scheme used (and thus if HTTPS is enabled). This is used to force TLS requirement for some authentication Options.

Constructors

Http

HTTP

Https

HTTPS

Instances

Eq Scheme

Defined in Network.HTTP.Req

Methods

(==) :: Scheme -> Scheme -> Bool

(/=) :: Scheme -> Scheme -> Bool

Data Scheme

Defined in Network.HTTP.Req

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Scheme -> c Scheme

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Scheme

toConstr :: Scheme -> Constr

dataTypeOf :: Scheme -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Scheme)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Scheme)

gmapT :: (forall b. Data b => b -> b) -> Scheme -> Scheme

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Scheme -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Scheme -> r

gmapQ :: (forall d. Data d => d -> u) -> Scheme -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Scheme -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Scheme -> m Scheme

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Scheme -> m Scheme

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Scheme -> m Scheme

Ord Scheme

Defined in Network.HTTP.Req

Methods

compare :: Scheme -> Scheme -> Ordering

(<) :: Scheme -> Scheme -> Bool

(<=) :: Scheme -> Scheme -> Bool

(>) :: Scheme -> Scheme -> Bool

(>=) :: Scheme -> Scheme -> Bool

max :: Scheme -> Scheme -> Scheme

min :: Scheme -> Scheme -> Scheme

Show Scheme

Defined in Network.HTTP.Req

Methods

showsPrec :: Int -> Scheme -> ShowS

show :: Scheme -> String

showList :: [Scheme] -> ShowS

Generic Scheme

Defined in Network.HTTP.Req

Associated Types

type Rep Scheme :: Type -> Type

Methods

from :: Scheme -> Rep Scheme x

to :: Rep Scheme x -> Scheme

Lift Scheme

Defined in Network.HTTP.Req

Methods

lift :: Scheme -> Q Exp

liftTyped :: Scheme -> Q (TExp Scheme)

type Rep Scheme

Defined in Network.HTTP.Req

type Rep Scheme = D1 ('MetaData "Scheme" "Network.HTTP.Req" "req-3.13.0-Kvi8nvPJvoxGi19Xb00npT" 'False) (C1 ('MetaCons "Http" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Https" 'PrefixI 'False) (U1 :: Type -> Type))