----------------------------------------------------------------------------- -- | -- Module : Network.HTTP -- Copyright : See LICENSE file -- License : BSD -- -- Maintainer : Ganesh Sittampalam -- Stability : experimental -- Portability : non-portable (not tested) -- -- The 'Network.HTTP' module provides a simple interface for sending and -- receiving content over HTTP in Haskell. Here's how to fetch a document from -- a URL and return it as a String: -- -- > -- > simpleHTTP (getRequest "http://www.haskell.org/") >>= fmap (take 100) . getResponseBody -- > -- fetch document and return it (as a 'String'.) -- -- Other functions let you control the submission and transfer of HTTP -- 'Request's and 'Response's more carefully, letting you integrate the use -- of 'Network.HTTP' functionality into your application. -- -- The module also exports the main types of the package, 'Request' and 'Response', -- along with 'Header' and functions for working with these. -- -- The actual functionality is implemented by modules in the @Network.HTTP.*@ -- namespace, letting you either use the default implementation here -- by importing @Network.HTTP@ or, for more specific uses, selectively -- import the modules in @Network.HTTP.*@. To wit, more than one kind of -- representation of the bulk data that flows across a HTTP connection is -- supported. (see "Network.HTTP.HandleStream".) -- -- /NOTE:/ The 'Request' send actions will normalize the @Request@ prior to transmission. -- Normalization such as having the request path be in the expected form and, possibly, -- introduce a default @Host:@ header if one isn't already present. -- Normalization also takes the @"user:pass\@"@ portion out of the the URI, -- if it was supplied, and converts it into @Authorization: Basic$ header. -- If you do not -- want the requests tampered with, but sent as-is, please import and use the -- the "Network.HTTP.HandleStream" or "Network.HTTP.Stream" modules instead. They -- export the same functions, but leaves construction and any normalization of -- @Request@s to the user. -- -- /NOTE:/ This package only supports HTTP; it does not support HTTPS. -- Attempts to use HTTPS result in an error. ----------------------------------------------------------------------------- module Network.HTTP ( module Network.HTTP.Base , module Network.HTTP.Headers {- the functionality that the implementation modules, Network.HTTP.HandleStream and Network.HTTP.Stream, exposes: -} , simpleHTTP -- :: Request -> IO (Result Response) , simpleHTTP_ -- :: Stream s => s -> Request -> IO (Result Response) , sendHTTP -- :: Stream s => s -> Request -> IO (Result Response) , sendHTTP_notify -- :: Stream s => s -> Request -> IO () -> IO (Result Response) , receiveHTTP -- :: Stream s => s -> IO (Result Request) , respondHTTP -- :: Stream s => s -> Response -> IO () , module Network.TCP , getRequest -- :: String -> Request_String , headRequest -- :: String -> Request_String , postRequest -- :: String -> Request_String , postRequestWithBody -- :: String -> String -> String -> Request_String , getResponseBody -- :: Result (Request ty) -> IO ty , getResponseCode -- :: Result (Request ty) -> IO ResponseCode ) where ----------------------------------------------------------------- ------------------ Imports -------------------------------------- ----------------------------------------------------------------- import Network.HTTP.Headers import Network.HTTP.Base import qualified Network.HTTP.HandleStream as S -- old implementation: import Network.HTTP.Stream import Network.TCP import Network.Stream ( Result ) import Network.URI ( parseURI ) import Data.Maybe ( fromMaybe ) {- Note: if you switch over/back to using Network.HTTP.Stream here, you'll have to wrap the results from 'openStream' as Connections via 'hstreamToConnection' prior to delegating to the Network.HTTP.Stream functions. -} -- | @simpleHTTP req@ transmits the 'Request' @req@ by opening a /direct/, non-persistent -- connection to the HTTP server that @req@ is destined for, followed by transmitting -- it and gathering up the response as a 'Result'. Prior to sending the request, -- it is normalized (via 'normalizeRequest'). If you have to mediate the request -- via an HTTP proxy, you will have to normalize the request yourself. Or switch to -- using 'Network.Browser' instead. -- -- Examples: -- -- > simpleHTTP (getRequest "http://hackage.haskell.org/") -- > simpleHTTP (getRequest "http://hackage.haskell.org:8012/") simpleHTTP :: (HStream ty) => Request ty -> IO (Result (Response ty)) simpleHTTP r = do auth <- getAuth r failHTTPS (rqURI r) c <- openStream (host auth) (fromMaybe 80 (port auth)) let norm_r = normalizeRequest defaultNormalizeRequestOptions{normDoClose=True} r simpleHTTP_ c norm_r -- | Identical to 'simpleHTTP', but acting on an already opened stream. simpleHTTP_ :: HStream ty => HandleStream ty -> Request ty -> IO (Result (Response ty)) simpleHTTP_ s r = do let norm_r = normalizeRequest defaultNormalizeRequestOptions{normDoClose=True} r S.sendHTTP s norm_r -- | @sendHTTP hStream httpRequest@ transmits @httpRequest@ (after normalization) over -- @hStream@, but does not alter the status of the connection, nor request it to be -- closed upon receiving the response. sendHTTP :: HStream ty => HandleStream ty -> Request ty -> IO (Result (Response ty)) sendHTTP conn rq = do let norm_r = normalizeRequest defaultNormalizeRequestOptions rq S.sendHTTP conn norm_r -- | @sendHTTP_notify hStream httpRequest action@ behaves like 'sendHTTP', but -- lets you supply an IO @action@ to execute once the request has been successfully -- transmitted over the connection. Useful when you want to set up tracing of -- request transmission and its performance. sendHTTP_notify :: HStream ty => HandleStream ty -> Request ty -> IO () -> IO (Result (Response ty)) sendHTTP_notify conn rq onSendComplete = do let norm_r = normalizeRequest defaultNormalizeRequestOptions rq S.sendHTTP_notify conn norm_r onSendComplete -- | @receiveHTTP hStream@ reads a 'Request' from the 'HandleStream' @hStream@ receiveHTTP :: HStream ty => HandleStream ty -> IO (Result (Request ty)) receiveHTTP conn = S.receiveHTTP conn -- | @respondHTTP hStream httpResponse@ transmits an HTTP 'Response' over -- the 'HandleStream' @hStream@. It could be used to implement simple web -- server interactions, performing the dual role to 'sendHTTP'. respondHTTP :: HStream ty => HandleStream ty -> Response ty -> IO () respondHTTP conn rsp = S.respondHTTP conn rsp -- | A convenience constructor for a GET 'Request'. -- -- If the URL isn\'t syntactically valid, the function raises an error. getRequest :: String -- ^URL to fetch -> Request_String -- ^The constructed request getRequest urlString = case parseURI urlString of Nothing -> error ("getRequest: Not a valid URL - " ++ urlString) Just u -> mkRequest GET u -- | A convenience constructor for a HEAD 'Request'. -- -- If the URL isn\'t syntactically valid, the function raises an error. headRequest :: String -- ^URL to fetch -> Request_String -- ^The constructed request headRequest urlString = case parseURI urlString of Nothing -> error ("headRequest: Not a valid URL - " ++ urlString) Just u -> mkRequest HEAD u -- | A convenience constructor for a POST 'Request'. -- -- If the URL isn\'t syntactically valid, the function raises an error. postRequest :: String -- ^URL to POST to -> Request_String -- ^The constructed request postRequest urlString = case parseURI urlString of Nothing -> error ("postRequest: Not a valid URL - " ++ urlString) Just u -> mkRequest POST u -- | A convenience constructor for a POST 'Request'. -- -- It constructs a request and sets the body as well as -- the Content-Type and Content-Length headers. The contents of the body -- are forced to calculate the value for the Content-Length header. -- -- If the URL isn\'t syntactically valid, the function raises an error. postRequestWithBody :: String -- ^URL to POST to -> String -- ^Content-Type of body -> String -- ^The body of the request -> Request_String -- ^The constructed request postRequestWithBody urlString typ body = case parseURI urlString of Nothing -> error ("postRequestWithBody: Not a valid URL - " ++ urlString) Just u -> setRequestBody (mkRequest POST u) (typ, body) -- | @getResponseBody response@ takes the response of a HTTP requesting action and -- tries to extricate the body of the 'Response' @response@. If the request action -- returned an error, an IO exception is raised. getResponseBody :: Result (Response ty) -> IO ty getResponseBody (Left err) = fail (show err) getResponseBody (Right r) = return (rspBody r) -- | @getResponseBody response@ takes the response of a HTTP requesting action and -- tries to extricate the status code of the 'Response' @response@. If the request action -- returned an error, an IO exception is raised. getResponseCode :: Result (Response ty) -> IO ResponseCode getResponseCode (Left err) = fail (show err) getResponseCode (Right r) = return (rspCode r) -- -- * TODO -- - request pipelining -- - https upgrade (includes full TLS, i.e. SSL, implementation) -- - use of Stream classes will pay off -- - consider C implementation of encryption\/decryption -- - comm timeouts -- - MIME & entity stuff (happening in separate module) -- - support \"*\" uri-request-string for OPTIONS request method -- -- -- * Header notes: -- -- [@Host@] -- Required by HTTP\/1.1, if not supplied as part -- of a request a default Host value is extracted -- from the request-uri. -- -- [@Connection@] -- If this header is present in any request or -- response, and it's value is "close", then -- the current request\/response is the last -- to be allowed on that connection. -- -- [@Expect@] -- Should a request contain a body, an Expect -- header will be added to the request. The added -- header has the value \"100-continue\". After -- a 417 \"Expectation Failed\" response the request -- is attempted again without this added Expect -- header. -- -- [@TransferEncoding,ContentLength,...@] -- if request is inconsistent with any of these -- header values then you may not receive any response -- or will generate an error response (probably 4xx). -- -- -- * Response code notes -- Some response codes induce special behaviour: -- -- [@1xx@] \"100 Continue\" will cause any unsent request body to be sent. -- \"101 Upgrade\" will be returned. -- Other 1xx responses are ignored. -- -- [@417@] The reason for this code is \"Expectation failed\", indicating -- that the server did not like the Expect \"100-continue\" header -- added to a request. Receipt of 417 will induce another -- request attempt (without Expect header), unless no Expect header -- had been added (in which case 417 response is returned).