Safe Haskell | None |
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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) import Network.HTTP.Conduit import qualified Data.Conduit as C main :: IO () main = do request <- parseUrl "http://google.com/" withManager $ \manager -> 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 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' <- parseUrl "http://example.com/secret-page" let request = request' { cookieJar = Just $ createCookieJar [cookie] } E.catch (withManager $ httpLbs request) (\(StatusCodeException s _ _) -> if statusCode==403 then putStrLn "login failed" else return ())
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' <- parseUrl "http://www.yesodweb.com/does-not-exist" let request = request' { checkStatus = \_ _ -> Nothing } res <- withManager $ httpLbs request print res
- simpleHttp :: MonadIO m => String -> m ByteString
- httpLbs :: (MonadBaseControl IO m, MonadResource m) => Request m -> Manager -> m (Response ByteString)
- http :: (MonadResource m, MonadBaseControl IO m) => Request m -> Manager -> m (Response (ResumableSource m ByteString))
- data Proxy = Proxy {
- proxyHost :: ByteString
- proxyPort :: Int
- data RequestBody m
- data Request m
- def :: Default a => a
- method :: Request m -> Method
- secure :: Request m -> Bool
- clientCertificates :: Request m -> [(X509, Maybe PrivateKey)]
- host :: Request m -> ByteString
- port :: Request m -> Int
- path :: Request m -> ByteString
- queryString :: Request m -> ByteString
- requestHeaders :: Request m -> RequestHeaders
- requestBody :: Request m -> RequestBody m
- proxy :: Request m -> Maybe Proxy
- socksProxy :: Request m -> Maybe SocksConf
- hostAddress :: Request m -> Maybe HostAddress
- rawBody :: Request m -> Bool
- decompress :: Request m -> ContentType -> Bool
- redirectCount :: Request m -> Int
- checkStatus :: Request m -> Status -> ResponseHeaders -> CookieJar -> Maybe SomeException
- responseTimeout :: Request m -> Maybe Int
- cookieJar :: Request m -> Maybe CookieJar
- getConnectionWrapper :: Request m -> forall n. (MonadResource n, MonadBaseControl IO n) => Maybe Int -> HttpException -> n (ConnRelease n, ConnInfo, ManagedConn) -> n (Maybe Int, (ConnRelease n, ConnInfo, ManagedConn))
- 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, MonadThrow m, MonadUnsafeIO m) => (Manager -> ResourceT m a) -> m a
- withManagerSettings :: (MonadIO m, MonadBaseControl IO m, MonadThrow m, MonadUnsafeIO m) => ManagerSettings -> (Manager -> ResourceT m a) -> m a
- data ManagerSettings
- managerConnCount :: ManagerSettings -> Int
- managerCheckCerts :: ManagerSettings -> CertificateStore -> ByteString -> [X509] -> IO CertificateUsage
- managerCertStore :: ManagerSettings -> IO CertificateStore
- managerResponseTimeout :: ManagerSettings -> Maybe Int
- defaultCheckCerts :: CertificateStore -> ByteString -> [X509] -> IO CertificateUsage
- data Cookie = Cookie {}
- data CookieJar
- createCookieJar :: [Cookie] -> CookieJar
- destroyCookieJar :: CookieJar -> [Cookie]
- parseUrl :: Failure HttpException m => String -> m (Request m')
- applyBasicAuth :: ByteString -> ByteString -> Request m -> Request m
- addProxy :: ByteString -> Int -> Request m -> Request m
- lbsResponse :: Monad m => Response (ResumableSource m ByteString) -> m (Response ByteString)
- getRedirectedRequest :: Request m -> ResponseHeaders -> CookieJar -> Int -> Maybe (Request m)
- alwaysDecompress :: ContentType -> Bool
- browserDecompress :: ContentType -> Bool
- urlEncodedBody :: Monad m => [(ByteString, ByteString)] -> Request m' -> Request m
- data HttpException
- = StatusCodeException Status ResponseHeaders CookieJar
- | InvalidUrlException String String
- | TooManyRedirects [Response ByteString]
- | UnparseableRedirect (Response ByteString)
- | TooManyRetries
- | HttpParserException String
- | HandshakeFailed
- | OverlongHeaders
- | ResponseTimeout
- | FailedConnectionException String Int
- | ExpectedBlankAfter100Continue
- | InvalidStatusLine ByteString
- | InvalidHeader ByteString
- | InternalIOException IOException
- | ProxyConnectException ByteString Int (Either ByteString HttpException)
- | NoResponseDataReceived
- | TlsException SomeException
- | ResponseBodyTooShort Word64 Word64
- | InvalidChunkHeaders
Perform a request
simpleHttp :: MonadIO m => String -> m ByteStringSource
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 parseUrl
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 :: (MonadBaseControl IO m, MonadResource m) => Request m -> 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
.
Note: Unlike previous versions, this function will perform redirects, as
specified by the redirectCount
setting.
http :: (MonadResource m, MonadBaseControl IO m) => Request m -> Manager -> m (Response (ResumableSource m ByteString))Source
The most low-level function for initiating an HTTP request.
The first argument to this function gives a full specification
on the request: the host to connect to, whether to use SSL,
headers, etc. Please see Request
for full details. The
second argument specifies which Manager
should be used.
This function then returns a Response
with a
Source
. The Response
contains the status code
and headers that were sent back to us, and the
Source
contains the body of the request. Note
that this Source
allows you to have fully
interleaved IO actions during your HTTP download, making it
possible to download very large responses in constant memory.
You may also directly connect the returned Source
into a Sink
, perhaps a file or another socket.
An important note: the response body returned by this function represents a
live HTTP connection. As such, if you do not use the response body, an open
socket will be retained until the containing ResourceT
block exits. If you
do not need the response body, it is recommended that you explicitly shut
down the connection immediately, using the pattern:
responseBody res $$+- return ()
As a more thorough example, consider the following program. Without the explicit response body closing, the program will run out of file descriptors around the 1000th request (depending on the operating system limits).
import Control.Monad (replicateM_) import Control.Monad.IO.Class (liftIO) import Data.Conduit (($$+-)) import Network (withSocketsDo) import Network.HTTP.Conduit main = withSocketsDo $ withManager $ \manager -> do req <- parseUrl "http://localhost/" mapM_ (worker manager req) [1..5000] worker manager req i = do res <- http req manager responseBody res $$+- return () -- The important line liftIO $ print (i, responseStatus res)
Note: Unlike previous versions, this function will perform redirects, as
specified by the redirectCount
setting.
Datatypes
Define a HTTP proxy, consisting of a hostname and port number.
Proxy | |
|
data RequestBody m Source
When using one of the
RequestBodySource
/ RequestBodySourceChunked
constructors,
you must ensure
that the Source
can be called multiple times. Usually this
is not a problem.
The RequestBodySourceChunked
will send a chunked request
body, note that not all servers support this. Only use
RequestBodySourceChunked
if you know the server you're
sending to supports chunked request bodies.
RequestBodyLBS ByteString | |
RequestBodyBS ByteString | |
RequestBodyBuilder Int64 Builder | |
RequestBodySource Int64 (Source m Builder) | |
RequestBodySourceChunked (Source m Builder) |
Show (RequestBody m) | Since 1.8.7 |
Monad m => Monoid (RequestBody m) | Since 1.8.7 |
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 parseUrl
.
The constructor for this data type is not exposed. Instead, you should use
either the def
method to retrieve a default instance, or parseUrl
to
construct from a URL, and then use the records below to make modifications.
This approach allows http-conduit to add configuration options without
breaking backwards compatibility.
For example, to construct a POST request, you could do something like:
initReq <- parseUrl "http://www.example.com/path" let req = initReq { method = "POST" }
For more information, please see http://www.yesodweb.com/book/settings-types.
clientCertificates :: Request m -> [(X509, Maybe PrivateKey)]Source
SSL client certificates
host :: Request m -> ByteStringSource
path :: Request m -> ByteStringSource
Everything from the host to the query string.
queryString :: Request m -> ByteStringSource
requestHeaders :: Request m -> RequestHeadersSource
Custom HTTP request headers
As already stated in the introduction, the Content-Length and Host headers are set automatically by this module, and shall not be added to requestHeaders.
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.
requestBody :: Request m -> RequestBody mSource
socksProxy :: Request m -> Maybe SocksConfSource
Optional SOCKS proxy.
hostAddress :: Request m -> Maybe HostAddressSource
Optional resolved host address.
Since 1.8.9
rawBody :: Request m -> BoolSource
If True
, a chunked and/or gzipped body will not be
decoded. Use with caution.
decompress :: Request m -> ContentType -> BoolSource
Predicate to specify whether gzipped data should be
decompressed on the fly (see alwaysDecompress
and
browserDecompress
). Default: browserDecompress.
redirectCount :: Request m -> IntSource
How many redirects to follow when getting a resource. 0 means follow no redirects. Default value: 10.
checkStatus :: Request m -> Status -> ResponseHeaders -> CookieJar -> Maybe SomeExceptionSource
Check the status code. Note that this will run after all redirects are
performed. Default: return a StatusCodeException
on non-2XX responses.
responseTimeout :: Request m -> Maybe IntSource
Number of microseconds to wait for a response. If Nothing
, will wait
indefinitely. Default: 5 seconds.
cookieJar :: Request m -> Maybe CookieJarSource
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 1.9.0
getConnectionWrapper :: Request m -> forall n. (MonadResource n, MonadBaseControl IO n) => Maybe Int -> HttpException -> n (ConnRelease n, ConnInfo, ManagedConn) -> n (Maybe Int, (ConnRelease n, ConnInfo, ManagedConn))Source
Wraps the calls for getting new connections. This can be useful for
instituting some kind of timeouts. The first argument is the value of
responseTimeout
. Second argument is the exception to be thrown on
failure.
Default: If responseTimeout
is Nothing
, does nothing. Otherwise,
institutes timeout, and returns remaining time for responseTimeout
.
Since 1.8.8
Response
A simple representation of the HTTP response created by lbsConsumer
.
responseStatus :: Response body -> StatusSource
Status code of the response.
responseVersion :: Response body -> HttpVersionSource
HTTP version used by the server.
responseHeaders :: Response body -> ResponseHeadersSource
Response headers sent by the server.
responseBody :: Response body -> bodySource
Response body sent by the server.
responseCookieJar :: Response body -> CookieJarSource
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.
Manager
Keeps track of open connections for keep-alive.
If possible, you should share a single Manager
between multiple threads and requests.
newManager :: ManagerSettings -> IO ManagerSource
Create a Manager
. You must manually call closeManager
to shut it down.
Creating a new Manager
is an expensive operation, you are advised to share
a single Manager
between requests instead.
closeManager :: Manager -> IO ()Source
withManager :: (MonadIO m, MonadBaseControl IO m, MonadThrow m, MonadUnsafeIO m) => (Manager -> ResourceT m a) -> m aSource
Create a new manager, use it in the provided function, and then release it.
This function uses the default manager settings. For more control, use
withManagerSettings
.
withManagerSettings :: (MonadIO m, MonadBaseControl IO m, MonadThrow m, MonadUnsafeIO m) => ManagerSettings -> (Manager -> ResourceT m a) -> m aSource
Create a new manager with provided settings, use it in the provided function, and then release it.
Settings
data ManagerSettings Source
Settings for a Manager
. Please use the def
function and then modify
individual settings.
managerConnCount :: ManagerSettings -> IntSource
Number of connections to a single host to keep alive. Default: 10.
managerCheckCerts :: ManagerSettings -> CertificateStore -> ByteString -> [X509] -> IO CertificateUsageSource
Check if the server certificate is valid. Only relevant for HTTPS.
managerCertStore :: ManagerSettings -> IO CertificateStoreSource
Load up the certificate store. By default uses the system store.
managerResponseTimeout :: ManagerSettings -> Maybe IntSource
Default timeout (in microseconds) to be applied to requests which do not provide a timeout value.
Default is 5 seconds
Since 1.9.3
Defaults
defaultCheckCerts :: CertificateStore -> ByteString -> [X509] -> IO CertificateUsageSource
Check certificates using the operating system's certificate checker.
Cookies
createCookieJar :: [Cookie] -> CookieJarSource
destroyCookieJar :: CookieJar -> [Cookie]Source
Utility functions
applyBasicAuth :: ByteString -> ByteString -> Request m -> Request mSource
addProxy :: ByteString -> Int -> Request m -> Request mSource
Add a proxy to the Request so that the Request when executed will use the provided proxy.
lbsResponse :: Monad m => Response (ResumableSource m ByteString) -> m (Response ByteString)Source
Convert a Response
that has a Source
body to one with a lazy
ByteString
body.
getRedirectedRequest :: Request m -> ResponseHeaders -> CookieJar -> Int -> Maybe (Request m)Source
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 parseUrl
.
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 :: ContentType -> BoolSource
Always decompress a compressed stream.
browserDecompress :: ContentType -> BoolSource
Decompress a compressed stream unless the content-type is 'application/x-tar'.
Request bodies
Network.HTTP.Conduit.MultipartFormData provides an API for building form-data request bodies.
urlEncodedBody :: Monad m => [(ByteString, ByteString)] -> Request m' -> Request mSource
Add url-encoded parameters to the Request
.
This sets a new requestBody
, adds a content-type request header and
changes the method
to POST.
Exceptions
data HttpException Source
StatusCodeException Status ResponseHeaders CookieJar | |
InvalidUrlException String String | |
TooManyRedirects [Response ByteString] | List of encountered responses containing redirects in reverse chronological order; including last redirect, which triggered the exception and was not followed. |
UnparseableRedirect (Response ByteString) | Response containing unparseable redirect. |
TooManyRetries | |
HttpParserException String | |
HandshakeFailed | |
OverlongHeaders | |
ResponseTimeout | |
FailedConnectionException String Int | host/port |
ExpectedBlankAfter100Continue | |
InvalidStatusLine ByteString | |
InvalidHeader ByteString | |
InternalIOException IOException | |
ProxyConnectException ByteString Int (Either ByteString HttpException) | host/port |
NoResponseDataReceived | |
TlsException SomeException | |
ResponseBodyTooShort Word64 Word64 | Expected size/actual size. Since 1.9.4 |
InvalidChunkHeaders | Since 1.9.4 |