Safe Haskell | None |
---|---|
Language | Haskell98 |
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://haskell-lang.org/library/http-client
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 = 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` (\ex -> case ex of HttpExceptionRequest _ (StatusCodeException res _) -> if statusCode (responseStatus res) == 403 then (putStrLn "login failed" >> return Nothing) else return Nothing _ -> E.throw ex)
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 = 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.
- simpleHttp :: MonadIO m => String -> m ByteString
- httpLbs :: MonadIO m => Request -> Manager -> m (Response ByteString)
- http :: MonadResource m => Request -> Manager -> m (Response (ResumableSource m ByteString))
- data Proxy :: * = Proxy {
- proxyHost :: ByteString
- proxyPort :: Int
- data RequestBody :: *
- data Request :: *
- method :: Request -> Method
- secure :: Request -> Bool
- host :: Request -> ByteString
- port :: Request -> Int
- path :: Request -> ByteString
- queryString :: Request -> ByteString
- requestHeaders :: Request -> RequestHeaders
- requestBody :: Request -> RequestBody
- proxy :: Request -> Maybe Proxy
- hostAddress :: Request -> Maybe HostAddress
- rawBody :: Request -> Bool
- decompress :: Request -> ByteString -> Bool
- redirectCount :: Request -> Int
- checkResponse :: Request -> Request -> Response BodyReader -> IO ()
- responseTimeout :: Request -> ResponseTimeout
- cookieJar :: Request -> Maybe CookieJar
- requestVersion :: Request -> HttpVersion
- setQueryString :: [(ByteString, Maybe ByteString)] -> Request -> Request
- requestBodySource :: Int64 -> Source (ResourceT IO) ByteString -> RequestBody
- requestBodySourceChunked :: Source (ResourceT IO) ByteString -> RequestBody
- requestBodySourceIO :: Int64 -> Source IO ByteString -> RequestBody
- requestBodySourceChunkedIO :: Source IO ByteString -> RequestBody
- data Response body :: * -> *
- responseStatus :: Response body -> Status
- responseVersion :: Response body -> HttpVersion
- responseHeaders :: Response body -> ResponseHeaders
- responseBody :: Response body -> body
- responseCookieJar :: Response body -> CookieJar
- data Manager :: *
- newManager :: ManagerSettings -> IO Manager
- closeManager :: Manager -> IO ()
- withManager :: (MonadIO m, MonadBaseControl IO m) => (Manager -> ResourceT m a) -> m a
- withManagerSettings :: (MonadIO m, MonadBaseControl IO m) => ManagerSettings -> (Manager -> ResourceT m a) -> m a
- data ManagerSettings :: *
- conduitManagerSettings :: ManagerSettings
- tlsManagerSettings :: ManagerSettings
- mkManagerSettings :: TLSSettings -> Maybe SockSettings -> ManagerSettings
- managerConnCount :: ManagerSettings -> Int
- managerResponseTimeout :: ManagerSettings -> ResponseTimeout
- managerTlsConnection :: ManagerSettings -> IO (Maybe HostAddress -> String -> Int -> IO Connection)
- data ResponseTimeout :: *
- responseTimeoutMicro :: Int -> ResponseTimeout
- responseTimeoutNone :: ResponseTimeout
- responseTimeoutDefault :: ResponseTimeout
- data Cookie :: * = Cookie {}
- data CookieJar :: *
- createCookieJar :: [Cookie] -> CookieJar
- destroyCookieJar :: CookieJar -> [Cookie]
- parseUrl :: MonadThrow m => String -> m Request
- parseUrlThrow :: MonadThrow m => String -> m Request
- parseRequest :: MonadThrow m => String -> m Request
- parseRequest_ :: String -> Request
- defaultRequest :: Request
- applyBasicAuth :: ByteString -> ByteString -> Request -> Request
- addProxy :: ByteString -> Int -> Request -> Request
- lbsResponse :: Monad m => Response (ResumableSource m ByteString) -> m (Response ByteString)
- getRedirectedRequest :: Request -> ResponseHeaders -> CookieJar -> Int -> Maybe Request
- alwaysDecompress :: ByteString -> Bool
- browserDecompress :: ByteString -> Bool
- urlEncodedBody :: [(ByteString, ByteString)] -> Request -> Request
- data HttpException :: *
- data HttpExceptionContent :: *
- = StatusCodeException (Response ()) ByteString
- | TooManyRedirects [Response ByteString]
- | OverlongHeaders
- | ResponseTimeout
- | ConnectionTimeout
- | ConnectionFailure SomeException
- | InvalidStatusLine ByteString
- | InvalidHeader ByteString
- | InternalException SomeException
- | ProxyConnectException ByteString Int Status
- | NoResponseDataReceived
- | TlsNotSupported
- | WrongRequestBodyStreamSize Word64 Word64
- | ResponseBodyTooShort Word64 Word64
- | InvalidChunkHeaders
- | IncompleteHeaders
- | InvalidDestinationHost ByteString
- | HttpZlibException ZlibException
- | InvalidProxyEnvironmentVariable Text Text
- | ConnectionClosed
- | InvalidProxySettings Text
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
Define a HTTP proxy, consisting of a hostname and port number.
Proxy | |
|
data RequestBody :: * #
When using one of the RequestBodyStream
/ RequestBodyStreamChunked
constructors, you must ensure that the GivesPopper
can be called multiple
times. Usually this is not a problem.
The RequestBodyStreamChunked
will send a chunked request body. Note that
not all servers support this. Only use RequestBodyStreamChunked
if you
know the server you're sending to supports chunked request bodies.
Since 0.1.0
RequestBodyLBS ByteString | |
RequestBodyBS ByteString | |
RequestBodyBuilder Int64 Builder | |
RequestBodyStream Int64 (GivesPopper ()) | |
RequestBodyStreamChunked (GivesPopper ()) | |
RequestBodyIO (IO RequestBody) | Allows creation of a Since: 0.4.28 |
IsString RequestBody | Since 0.4.12 |
Monoid RequestBody | |
Request
All information on how to connect to a host and what should be sent in the HTTP request.
If you simply wish to download from a URL, see parseRequest
.
The constructor for this data type is not exposed. Instead, you should use
either the defaultRequest
value, or parseRequest
to
construct from a URL, and then use the records below to make modifications.
This approach allows http-client to add configuration options without
breaking backwards compatibility.
For example, to construct a POST request, you could do something like:
initReq <- parseRequest "http://www.example.com/path" let req = initReq { method = "POST" }
For more information, please see http://www.yesodweb.com/book/settings-types.
Since 0.1.0
host :: Request -> ByteString #
Requested host name, used for both the IP address to connect to and
the host
request header.
Since 0.1.0
The port to connect to. Also used for generating the host
request header.
Since 0.1.0
path :: Request -> ByteString #
Everything from the host to the query string.
Since 0.1.0
queryString :: Request -> ByteString #
Query string appended to the path.
Since 0.1.0
requestHeaders :: Request -> RequestHeaders #
Custom HTTP request headers
The Content-Length and Transfer-Encoding headers are set automatically
by this module, and shall not be added to requestHeaders
.
If not provided by the user, Host
will automatically be set based on
the host
and port
fields.
Moreover, the Accept-Encoding header is set implicitly to gzip for
convenience by default. This behaviour can be overridden if needed, by
setting the header explicitly to a different value. In order to omit the
Accept-Header altogether, set it to the empty string "". If you need an
empty Accept-Header (i.e. requesting the identity encoding), set it to a
non-empty white-space string, e.g. " ". See RFC 2616 section 14.3 for
details about the semantics of the Accept-Header field. If you request a
content-encoding not supported by this module, you will have to decode
it yourself (see also the decompress
field).
Note: Multiple header fields with the same field-name will result in multiple header fields being sent and therefore it's the responsibility of the client code to ensure that the rules from RFC 2616 section 4.2 are honoured.
Since 0.1.0
requestBody :: Request -> RequestBody #
Request body to be sent to the server.
Since 0.1.0
hostAddress :: Request -> Maybe HostAddress #
Optional resolved host address. May not be used by all backends.
Since 0.1.0
If True
, a chunked and/or gzipped body will not be
decoded. Use with caution.
Since 0.1.0
decompress :: Request -> ByteString -> Bool #
Predicate to specify whether gzipped data should be
decompressed on the fly (see alwaysDecompress
and
browserDecompress
). Argument is the mime type.
Default: browserDecompress.
Since 0.1.0
redirectCount :: Request -> Int #
How many redirects to follow when getting a resource. 0 means follow no redirects. Default value: 10.
Since 0.1.0
checkResponse :: Request -> Request -> Response BodyReader -> IO () #
Check the response immediately after receiving the status and headers. This can be useful for throwing exceptions on non-success status codes.
In previous versions of http-client, this went under the name
checkStatus
, but was renamed to avoid confusion about the new default
behavior (doing nothing).
Since: 0.5.0
responseTimeout :: Request -> ResponseTimeout #
Number of microseconds to wait for a response. If
Nothing
, will wait indefinitely. Default: use
managerResponseTimeout
(which by default is 30 seconds).
Since 0.1.0
cookieJar :: Request -> Maybe CookieJar #
A user-defined cookie jar.
If Nothing
, no cookie handling will take place, "Cookie" headers
in requestHeaders
will be sent raw, and responseCookieJar
will be
empty.
Since 0.1.0
requestVersion :: Request -> HttpVersion #
HTTP version to send to server.
Default: HTTP 1.1
Since 0.4.3
setQueryString :: [(ByteString, Maybe ByteString)] -> Request -> Request #
Set the query string to the given key/value pairs.
Since 0.3.6
Request body
requestBodySource :: Int64 -> Source (ResourceT IO) ByteString -> RequestBody Source #
requestBodySourceIO :: Int64 -> Source IO ByteString -> RequestBody Source #
Response
responseStatus :: Response body -> Status #
Status code of the response.
Since 0.1.0
responseVersion :: Response body -> HttpVersion #
HTTP version used by the server.
Since 0.1.0
responseHeaders :: Response body -> ResponseHeaders #
Response headers sent by the server.
Since 0.1.0
responseBody :: Response body -> body #
Response body sent by the server.
Since 0.1.0
responseCookieJar :: Response body -> CookieJar #
Cookies set on the client after interacting with the server. If
cookies have been disabled by setting cookieJar
to Nothing
, then
this will always be empty.
Since 0.1.0
Manager
Keeps track of open connections for keep-alive.
If possible, you should share a single Manager
between multiple threads and requests.
Since 0.1.0
newManager :: ManagerSettings -> IO Manager #
Create a Manager
. The Manager
will be shut down automatically via
garbage collection.
Creating a new Manager
is a relatively expensive operation, you are
advised to share a single Manager
between requests instead.
The first argument to this function is often defaultManagerSettings
,
though add-on libraries may provide a recommended replacement.
Since 0.1.0
closeManager :: Manager -> IO () #
Close all connections in a Manager
.
Note that this doesn't affect currently in-flight connections, meaning you can safely use it without hurting any queries you may have concurrently running.
Since 0.1.0
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 :: * #
Settings for a Manager
. Please use the defaultManagerSettings
function and then modify
individual settings. For more information, see http://www.yesodweb.com/book/settings-types.
Since 0.1.0
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
managerConnCount :: ManagerSettings -> Int #
Number of connections to a single host to keep alive. Default: 10.
Since 0.1.0
managerResponseTimeout :: ManagerSettings -> ResponseTimeout #
Default timeout to be applied to requests which do not provide a timeout value.
Default is 30 seconds
Since: 0.5.0
managerTlsConnection :: ManagerSettings -> IO (Maybe HostAddress -> String -> Int -> IO Connection) #
Create a TLS connection. Default behavior: throw an exception that TLS is not supported.
Since 0.1.0
Response timeout
data ResponseTimeout :: * #
How to deal with timing out a response
Since: 0.5.0
responseTimeoutMicro :: Int -> ResponseTimeout #
Specify a response timeout in microseconds
Since: 0.5.0
responseTimeoutNone :: ResponseTimeout #
Do not have a response timeout
Since: 0.5.0
responseTimeoutDefault :: ResponseTimeout #
Use the default response timeout
When used on a Request
, means: use the manager's timeout value
When used on a ManagerSettings
, means: default to 30 seconds
Since: 0.5.0
Cookies
createCookieJar :: [Cookie] -> CookieJar #
destroyCookieJar :: CookieJar -> [Cookie] #
Utility functions
parseUrl :: MonadThrow m => String -> m Request #
Deprecated synonym for parseUrlThrow
. You probably want
parseRequest
or parseRequest_
instead.
Since: 0.1.0
parseUrlThrow :: MonadThrow m => String -> m Request #
Same as parseRequest
, except will throw an HttpException
in
the event of a non-2XX response.
Since: 0.4.30
parseRequest :: MonadThrow m => String -> m Request #
Convert a URL into a Request
.
This defaults some of the values in Request
, such as setting method
to
GET and requestHeaders
to []
.
Since this function uses MonadThrow
, the return monad can be anything that is
an instance of MonadThrow
, such as IO
or Maybe
.
You can place the request method at the beginning of the URL separated by a space, e.g.:
@@
parseRequest "POST http://httpbin.org/post"
@@
Note that the request method must be provided as all capital letters.
Request
created by this function won't cause exceptions on non-2XX
response status codes.
To create a request which throws on non-2XX status codes, see parseUrlThrow
Since: 0.4.30
parseRequest_ :: String -> Request #
Same as parseRequest
, but in the cases of a parse error
generates an impure exception. Mostly useful for static strings which
are known to be correctly formatted.
A default request value
Since: 0.4.30
applyBasicAuth :: ByteString -> ByteString -> Request -> Request #
Add a Basic Auth header (with the specified user name and password) to the given Request. Ignore error handling:
applyBasicAuth "user" "pass" $ parseRequest_ url
NOTE: The function applyDigestAuth
is provided by the http-client-tls
package instead of this package due to extra dependencies. Please use that
package if you need to use digest authentication.
Since 0.1.0
addProxy :: ByteString -> Int -> Request -> Request #
Add a proxy to the Request so that the Request when executed will use the provided proxy.
Since 0.1.0
lbsResponse :: Monad m => Response (ResumableSource m ByteString) -> m (Response ByteString) Source #
getRedirectedRequest :: Request -> ResponseHeaders -> CookieJar -> Int -> Maybe Request #
If a request is a redirection (status code 3xx) this function will create
a new request from the old request, the server headers returned with the
redirection, and the redirection code itself. This function returns Nothing
if the code is not a 3xx, there is no location
header included, or if the
redirected response couldn't be parsed with parseRequest
.
If a user of this library wants to know the url chain that results from a specific request, that user has to re-implement the redirect-following logic themselves. An example of that might look like this:
myHttp req man = do (res, redirectRequests) <- (`runStateT` []) $ 'httpRedirect' 9000 (\req' -> do res <- http req'{redirectCount=0} man modify (\rqs -> req' : rqs) return (res, getRedirectedRequest req' (responseHeaders res) (responseCookieJar res) (W.statusCode (responseStatus res)) ) 'lift' req applyCheckStatus (checkStatus req) res return redirectRequests
Decompression predicates
alwaysDecompress :: ByteString -> Bool #
Always decompress a compressed stream.
browserDecompress :: ByteString -> Bool #
Decompress a compressed stream unless the content-type is 'application/x-tar'.
Request bodies
Network.HTTP.Client.MultipartFormData provides an API for building form-data request bodies.
urlEncodedBody :: [(ByteString, ByteString)] -> Request -> Request #
Add url-encoded parameters to the Request
.
This sets a new requestBody
, adds a content-type request header and
changes the method
to POST.
Since 0.1.0
Exceptions
data HttpException :: * #
An exception which may be generated by this library
Since: 0.5.0
HttpExceptionRequest Request HttpExceptionContent | Most exceptions are specific to a Since: 0.5.0 |
InvalidUrlException String String | A URL (first field) is invalid for a given reason (second argument). Since: 0.5.0 |
data HttpExceptionContent :: * #
StatusCodeException (Response ()) ByteString | Generated by the May include the beginning of the response body. Since: 0.5.0 |
TooManyRedirects [Response ByteString] | The server responded with too many redirects for a request. Contains the list of encountered responses containing redirects in reverse chronological order; including last redirect, which triggered the exception and was not followed. Since: 0.5.0 |
OverlongHeaders | Either too many headers, or too many total bytes in a single header, were returned by the server, and the memory exhaustion protection in this library has kicked in. Since: 0.5.0 |
ResponseTimeout | The server took too long to return a response. This can
be altered via Since: 0.5.0 |
ConnectionTimeout | Attempting to connect to the server timed out. Since: 0.5.0 |
ConnectionFailure SomeException | An exception occured when trying to connect to the server. Since: 0.5.0 |
InvalidStatusLine ByteString | The status line returned by the server could not be parsed. Since: 0.5.0 |
InvalidHeader ByteString | The given response header line could not be parsed Since: 0.5.0 |
InternalException SomeException | An exception was raised by an underlying library when performing the request. Most often, this is caused by a failing socket action or a TLS exception. Since: 0.5.0 |
ProxyConnectException ByteString Int Status | A non-200 status code was returned when trying to connect to the proxy server on the given host and port. Since: 0.5.0 |
NoResponseDataReceived | No response data was received from the server at all. This exception may deserve special handling within the library, since it may indicate that a pipelining has been used, and a connection thought to be open was in fact closed. Since: 0.5.0 |
TlsNotSupported | Exception thrown when using a Since: 0.5.0 |
WrongRequestBodyStreamSize Word64 Word64 | The request body provided did not match the expected size. Provides the expected and actual size. Since: 0.4.31 |
ResponseBodyTooShort Word64 Word64 | The returned response body is too short. Provides the expected size and actual size. Since: 0.5.0 |
InvalidChunkHeaders | A chunked response body had invalid headers. Since: 0.5.0 |
IncompleteHeaders | An incomplete set of response headers were returned. Since: 0.5.0 |
InvalidDestinationHost ByteString | The host we tried to connect to is invalid (e.g., an empty string). |
HttpZlibException ZlibException | An exception was thrown when inflating a response body. Since: 0.5.0 |
InvalidProxyEnvironmentVariable Text Text | Values in the proxy environment variable were invalid. Provides the environment variable name and its value. Since: 0.5.0 |
ConnectionClosed | Attempted to use a Since: 0.5.0 |
InvalidProxySettings Text | Proxy settings are not valid (Windows specific currently) @since 0.5.7 |