http-conduit-2.1.11: HTTP client package with conduit interface and HTTPS support.

Safe HaskellNone
LanguageHaskell98

Network.HTTP.Conduit

Contents

Description

Simpler API

The API below is rather low-level. The Network.HTTP.Simple module provides a higher-level API with built-in support for things like JSON request and response bodies. For most users, this will be an easier place to start. You can read the tutorial at:

https://github.com/commercialhaskell/jump/blob/master/doc/http-client.md

Lower-level API

This module contains everything you need to initiate HTTP connections. If you want a simple interface based on URLs, you can use simpleHttp. If you want raw power, http is the underlying workhorse of this package. Some examples:

-- Just download an HTML document and print it.
import Network.HTTP.Conduit
import qualified Data.ByteString.Lazy as L

main = simpleHttp "http://www.haskell.org/" >>= L.putStr

This example uses interleaved IO to write the response body to a file in constant memory space.

import Data.Conduit.Binary (sinkFile) -- Exported from the package conduit-extra
import Network.HTTP.Conduit
import qualified Data.Conduit as C
import Control.Monad.Trans.Resource (runResourceT)

main :: IO ()
main = do
     request <- parseRequest "http://google.com/"
     manager <- newManager tlsManagerSettings
     runResourceT $ do
         response <- http request manager
         responseBody response C.$$+- sinkFile "google.html"

The following headers are automatically set by this module, and should not be added to requestHeaders:

  • Cookie
  • Content-Length
  • Transfer-Encoding

Note: In previous versions, the Host header would be set by this module in all cases. Starting from 1.6.1, if a Host header is present in requestHeaders, it will be used in place of the header this module would have generated. This can be useful for calling a server which utilizes virtual hosting.

Use cookieJar If you want to supply cookies with your request:

{-# LANGUAGE OverloadedStrings #-}
import Network.HTTP.Conduit
import Network
import Data.Time.Clock
import Data.Time.Calendar
import qualified Control.Exception as E
import Network.HTTP.Types.Status (statusCode)

past :: UTCTime
past = UTCTime (ModifiedJulianDay 56200) (secondsToDiffTime 0)

future :: UTCTime
future = UTCTime (ModifiedJulianDay 562000) (secondsToDiffTime 0)

cookie :: Cookie
cookie = Cookie { cookie_name = "password_hash"
                , cookie_value = "abf472c35f8297fbcabf2911230001234fd2"
                , cookie_expiry_time = future
                , cookie_domain = "example.com"
                , cookie_path = "/"
                , cookie_creation_time = past
                , cookie_last_access_time = past
                , cookie_persistent = False
                , cookie_host_only = False
                , cookie_secure_only = False
                , cookie_http_only = False
                }

main = withSocketsDo $ do
     request' <- parseRequest "http://example.com/secret-page"
     manager <- newManager tlsManagerSettings
     let request = request' { cookieJar = Just $ createCookieJar [cookie] }
     (fmap Just (httpLbs request manager)) `E.catch`
             (\(StatusCodeException s _ _) ->
               if statusCode s==403 then (putStrLn "login failed" >> return Nothing) else return Nothing)

Any network code on Windows requires some initialization, and the network library provides withSocketsDo to perform it. Therefore, proper usage of this library will always involve calling that function at some point. The best approach is to simply call them at the beginning of your main function, such as:

import Network.HTTP.Conduit
import qualified Data.ByteString.Lazy as L
import Network (withSocketsDo)

main = withSocketsDo
     $ simpleHttp "http://www.haskell.org/" >>= L.putStr

Cookies are implemented according to RFC 6265.

Note that by default, the functions in this package will throw exceptions for non-2xx status codes. If you would like to avoid this, you should use checkStatus, e.g.:

import Data.Conduit.Binary (sinkFile)
import Network.HTTP.Conduit
import qualified Data.Conduit as C
import Network

main :: IO ()
main = withSocketsDo $ do
     request' <- parseRequest "http://www.yesodweb.com/does-not-exist"
     let request = request' { checkStatus = \_ _ _ -> Nothing }
     manager <- newManager tlsManagerSettings
     res <- httpLbs request manager
     print res

By default, when connecting to websites using HTTPS, functions in this package will throw an exception if the TLS certificate doesn't validate. To continue the HTTPS transaction even if the TLS cerficate validation fails, you should use mkManagerSetttings as follows:

import Network.Connection (TLSSettings (..))
import Network.HTTP.Conduit

main :: IO ()
main = do
    request <- parseRequest "https://github.com/"
    let settings = mkManagerSettings (TLSSettingsSimple True False False) Nothing
    manager <- newManager settings
    res <- httpLbs request manager
    print res

For more information, please be sure to read the documentation in the Network.HTTP.Client module.

Synopsis

Perform a request

simpleHttp :: MonadIO m => String -> m ByteString Source

Download the specified URL, following any redirects, and return the response body.

This function will throwIO an HttpException for any response with a non-2xx status code (besides 3xx redirects up to a limit of 10 redirects). It uses parseUrlThrow to parse the input. This function essentially wraps httpLbs.

Note: Even though this function returns a lazy bytestring, it does not utilize lazy I/O, and therefore the entire response body will live in memory. If you want constant memory usage, you'll need to use the conduit package and http directly.

Note: This function creates a new Manager. It should be avoided in production code.

httpLbs :: MonadIO m => Request -> Manager -> m (Response ByteString) Source

Download the specified Request, returning the results as a Response.

This is a simplified version of http for the common case where you simply want the response data as a simple datatype. If you want more power, such as interleaved actions on the response body during download, you'll need to use http directly. This function is defined as:

httpLbs = lbsResponse <=< http

Even though the Response contains a lazy bytestring, this function does not utilize lazy I/O, and therefore the entire response body will live in memory. If you want constant memory usage, you'll need to use conduit packages's Source returned by http.

This function will throwIO an HttpException for any response with a non-2xx status code (besides 3xx redirects up to a limit of 10 redirects). This behavior can be modified by changing the checkStatus field of your request.

Note: Unlike previous versions, this function will perform redirects, as specified by the redirectCount setting.

http :: MonadResource m => Request -> Manager -> m (Response (ResumableSource m ByteString)) Source

Datatypes

data Proxy :: *

Constructors

Proxy 

Request

data Request :: *

method :: Request -> Method

requestHeaders :: Request -> RequestHeaders

hostAddress :: Request -> Maybe HostAddress

checkStatus :: Request -> Status -> ResponseHeaders -> CookieJar -> Maybe SomeException

requestVersion :: Request -> HttpVersion

getConnectionWrapper :: Request -> Maybe Int -> HttpException -> IO (ConnRelease, Connection, ManagedConn) -> IO (Maybe Int, (ConnRelease, Connection, ManagedConn))

Request body

Response

data Response body :: * -> *

Instances

responseStatus :: Response body -> Status

responseVersion :: Response body -> HttpVersion

responseHeaders :: Response body -> ResponseHeaders

responseBody :: Response body -> body

Manager

data Manager :: *

Instances

HasHttpManager Manager 

withManager :: (MonadIO m, MonadBaseControl IO m) => (Manager -> ResourceT m a) -> m a Source

Deprecated: Please use newManager tlsManagerSettings

withManagerSettings :: (MonadIO m, MonadBaseControl IO m) => ManagerSettings -> (Manager -> ResourceT m a) -> m a Source

Deprecated: Please use newManager

Settings

data ManagerSettings :: *

conduitManagerSettings :: ManagerSettings Source

Deprecated: Use tlsManagerSettings

tlsManagerSettings :: ManagerSettings

Default TLS-enabled manager settings

mkManagerSettings :: TLSSettings -> Maybe SockSettings -> ManagerSettings

Create a TLS-enabled ManagerSettings with the given TLSSettings and SockSettings

managerTlsConnection :: ManagerSettings -> IO (Maybe HostAddress -> String -> Int -> IO Connection)

Cookies

Utility functions

lbsResponse :: Monad m => Response (ResumableSource m ByteString) -> m (Response ByteString) Source

getRedirectedRequest :: Request -> ResponseHeaders -> CookieJar -> Int -> Maybe Request

Decompression predicates

Request bodies

Network.HTTP.Client.MultipartFormData provides an API for building form-data request bodies.

Exceptions