HTTP-4000.2.20: A library for client-side HTTP

Copyright | See LICENSE file
License | BSD
Maintainer | Ganesh Sittampalam <ganesh@earth.li>
Stability | experimental
Portability | non-portable (not tested)
Safe Haskell | Safe
Language | Haskell98

Network.HTTP.Base

Contents

- Constants
- HTTP
- URL Encoding
- URI authority parsing

Description

Definitions of `Request` and `Response` types along with functions for normalizing them. It is assumed to be an internal module; user code should, if possible, import `Network.HTTP` to access the functionality that this module provides.

Additionally, the module exports internal functions for working with URLs, and for handling the processing of requests and responses coming back.

Synopsis

- httpVersion :: String
- data Request a = Request {
  - rqURI :: URI
  - rqMethod :: RequestMethod
  - rqHeaders :: [Header]
  - rqBody :: a
  }
- data Response a = Response {
  - rspCode :: ResponseCode
  - rspReason :: String
  - rspHeaders :: [Header]
  - rspBody :: a
  }
- data RequestMethod
  - = HEAD
  - | PUT
  - | GET
  - | POST
  - | DELETE
  - | OPTIONS
  - | TRACE
  - | CONNECT
  - | Custom String
- type Request_String = Request String
- type Response_String = Response String
- type HTTPRequest a = Request a
- type HTTPResponse a = Response a
- urlEncode :: String -> String
- urlDecode :: String -> String
- urlEncodeVars :: [(String, String)] -> String
- data URIAuthority = URIAuthority {
  - user :: Maybe String
  - password :: Maybe String
  - host :: String
  - port :: Maybe Int
  }
- parseURIAuthority :: String -> Maybe URIAuthority
- uriToAuthorityString :: URI -> String
- uriAuthToString :: URIAuth -> String
- uriAuthPort :: Maybe URI -> URIAuth -> Int
- reqURIAuth :: Request ty -> URIAuth
- parseResponseHead :: [String] -> Result ResponseData
- parseRequestHead :: [String] -> Result RequestData
- data ResponseNextStep
  - = Continue
  - | Retry
  - | Done
  - | ExpectEntity
  - | DieHorribly String
- matchResponse :: RequestMethod -> ResponseCode -> ResponseNextStep
- type ResponseData = (ResponseCode, String, [Header])
- type ResponseCode = (Int, Int, Int)
- type RequestData = (RequestMethod, URI, [Header])
- data NormalizeRequestOptions ty = NormalizeRequestOptions {
  - normDoClose :: Bool
  - normForProxy :: Bool
  - normUserAgent :: Maybe String
  - normCustoms :: [RequestNormalizer ty]
  }
- defaultNormalizeRequestOptions :: NormalizeRequestOptions ty
- type RequestNormalizer ty = NormalizeRequestOptions ty -> Request ty -> Request ty
- normalizeRequest :: NormalizeRequestOptions ty -> Request ty -> Request ty
- splitRequestURI :: URI -> (String, URI)
- getAuth :: Monad m => Request ty -> m URIAuthority
- normalizeRequestURI :: Bool -> String -> Request ty -> Request ty
- normalizeHostHeader :: Request ty -> Request ty
- findConnClose :: [Header] -> Bool
- linearTransfer :: (Int -> IO (Result a)) -> Int -> IO (Result ([Header], a))
- hopefulTransfer :: BufferOp a -> IO (Result a) -> [a] -> IO (Result ([Header], a))
- chunkedTransfer :: BufferOp a -> IO (Result a) -> (Int -> IO (Result a)) -> IO (Result ([Header], a))
- uglyDeathTransfer :: String -> IO (Result ([Header], a))
- readTillEmpty1 :: BufferOp a -> IO (Result a) -> IO (Result [a])
- readTillEmpty2 :: BufferOp a -> IO (Result a) -> [a] -> IO (Result [a])
- defaultGETRequest :: URI -> Request_String
- defaultGETRequest_ :: BufferType a => URI -> Request a
- mkRequest :: BufferType ty => RequestMethod -> URI -> Request ty
- setRequestBody :: Request_String -> (String, String) -> Request_String
- defaultUserAgent :: String
- httpPackageVersion :: String
- libUA :: String
- catchIO :: IO a -> (IOException -> IO a) -> IO a
- catchIO_ :: IO a -> IO a -> IO a
- responseParseError :: String -> String -> Result a
- getRequestVersion :: Request a -> Maybe String
- getResponseVersion :: Response a -> Maybe String
- setRequestVersion :: String -> Request a -> Request a
- setResponseVersion :: String -> Response a -> Response a
- failHTTPS :: Monad m => URI -> m ()

## Constants

httpVersion :: String

## HTTP

data Request a

An HTTP Request. The `Show` instance of this type is used for message serialisation, which means no body data is output.

Constructors

Request |
Fields rqURI :: URI might need changing in future 1) to support `*` uri in OPTIONS request 2) transparent support for both relative & absolute uris, although this should already work (leave scheme & host parts empty). rqMethod :: RequestMethod rqHeaders :: [Header] rqBody :: a

Instances

Show (Request a) |
HasHeaders (Request a) |

data Response a

An HTTP Response. The `Show` instance of this type is used for message serialisation, which means no body data is output, additionally the output will show an HTTP version of 1.1 instead of the actual version returned by a server.

Constructors

Response |
Fields rspCode :: ResponseCode rspReason :: String rspHeaders :: [Header] rspBody :: a

Instances

Show (Response a) |
HasHeaders (Response a) |

data RequestMethod

The HTTP request method, to be used in the `Request` object. We are missing a few of the stranger methods, but these are not really necessary until we add full TLS.

Constructors

HEAD |
PUT |
GET |
POST |
DELETE |
OPTIONS |
TRACE |
CONNECT |
Custom String |

Instances

Eq RequestMethod |
Show RequestMethod |

type Request_String = Request String

type Response_String = Response String

type HTTPRequest a = Request a

type HTTPResponse a = Response a

## URL Encoding

urlEncode :: String -> String

urlDecode :: String -> String

urlEncodeVars :: [(String, String)] -> String

## URI authority parsing

data URIAuthority

Constructors

URIAuthority |
Fields user :: Maybe String password :: Maybe String host :: String port :: Maybe Int

Instances

Eq URIAuthority |
Show URIAuthority |

parseURIAuthority :: String -> Maybe URIAuthority

Parse the authority part of a URL.

    RFC 1732, section 3.1:

          //<user>:<password>@<host>:<port>/<url-path>
     Some or all of the parts "<user>:<password>@", ":<password>",
     ":<port>", and "/<url-path>" may be excluded.

uriToAuthorityString :: URI -> String

uriAuthToString :: URIAuth -> String

uriAuthPort :: Maybe URI -> URIAuth -> Int

reqURIAuth :: Request ty -> URIAuth

parseResponseHead :: [String] -> Result ResponseData

parseRequestHead :: [String] -> Result RequestData

data ResponseNextStep

Constructors

Continue |
Retry |
Done |
ExpectEntity |
DieHorribly String |

matchResponse :: RequestMethod -> ResponseCode -> ResponseNextStep

type ResponseData = (ResponseCode, String, [Header])

`ResponseData` contains the head of a response payload; HTTP response code, accompanying text description + header fields.

type ResponseCode = (Int, Int, Int)

For easy pattern matching, HTTP response codes `xyz` are represented as `(x,y,z)`.

type RequestData = (RequestMethod, URI, [Header])

`RequestData` contains the head of a HTTP request; method, its URL along with the auxillary/supporting header data.

data NormalizeRequestOptions ty

`NormalizeRequestOptions` brings together the various defaulting/normalization options over `Request`s. Use `defaultNormalizeRequestOptions` for the standard selection of option

Constructors

NormalizeRequestOptions |
Fields normDoClose :: Bool normForProxy :: Bool normUserAgent :: Maybe String normCustoms :: [RequestNormalizer ty]

defaultNormalizeRequestOptions :: NormalizeRequestOptions ty

type RequestNormalizer ty = NormalizeRequestOptions ty -> Request ty -> Request ty

`RequestNormalizer` is the shape of a (pure) function that rewrites a request into some normalized form.

normalizeRequest :: NormalizeRequestOptions ty -> Request ty -> Request ty

`normalizeRequest opts req` is the entry point to use to normalize your request prior to transmission (or other use.) Normalization is controlled via the `NormalizeRequestOptions` record.

splitRequestURI :: URI -> (String, URI)

getAuth :: Monad m => Request ty -> m URIAuthority

`getAuth req` fishes out the authority portion of the URL in a request's `Host` header.

normalizeRequestURI :: Bool -> String -> Request ty -> Request ty

Deprecated: Please use Network.HTTP.Base.normalizeRequest instead

normalizeHostHeader :: Request ty -> Request ty

Deprecated: Please use Network.HTTP.Base.normalizeRequest instead

findConnClose :: [Header] -> Bool

linearTransfer :: (Int -> IO (Result a)) -> Int -> IO (Result ([Header], a))

Used when we know exactly how many bytes to expect.

hopefulTransfer :: BufferOp a -> IO (Result a) -> [a] -> IO (Result ([Header], a))

Used when nothing about data is known, Unfortunately waiting for a socket closure causes bad behaviour. Here we just take data once and give up the rest.

chunkedTransfer :: BufferOp a -> IO (Result a) -> (Int -> IO (Result a)) -> IO (Result ([Header], a))

A necessary feature of HTTP/1.1 Also the only transfer variety likely to return any footers.

uglyDeathTransfer :: String -> IO (Result ([Header], a))

Maybe in the future we will have a sensible thing to do here, at that time we might want to change the name.

readTillEmpty1 :: BufferOp a -> IO (Result a) -> IO (Result [a])

Remove leading crlfs then call readTillEmpty2 (not required by RFC)

readTillEmpty2 :: BufferOp a -> IO (Result a) -> [a] -> IO (Result [a])

Read lines until an empty line (CRLF), also accepts a connection close as end of input, which is not an HTTP/1.1 compliant thing to do - so probably indicates an error condition.

defaultGETRequest :: URI -> Request_String

defaultGETRequest_ :: BufferType a => URI -> Request a

mkRequest :: BufferType ty => RequestMethod -> URI -> Request ty

'mkRequest method uri' constructs a well formed request for the given HTTP method and URI. It does not normalize the URI for the request _nor_ add the required Host: header. That is done either explicitly by the user or when requests are normalized prior to transmission.

setRequestBody :: Request_String -> (String, String) -> Request_String

defaultUserAgent :: String

A default user agent string. The string is `"haskell-HTTP/$version"` where `$version` is the version of this HTTP package.

httpPackageVersion :: String

The version of this HTTP package as a string, e.g. `"4000.1.2"`. This may be useful to include in a user agent string so that you can determine from server logs what version of this package HTTP clients are using. This can be useful for tracking down HTTP compatibility quirks.

libUA :: String

Deprecated: Use defaultUserAgent instead (but note the user agent name change)

Deprecated. Use `defaultUserAgent`

catchIO :: IO a -> (IOException -> IO a) -> IO a

`catchIO a h` handles IO action exceptions throughout codebase; version-specific tweaks better go here.

catchIO_ :: IO a -> IO a -> IO a

responseParseError :: String -> String -> Result a

getRequestVersion :: Request a -> Maybe String

`getRequestVersion req` returns the HTTP protocol version of the request `req`. If `Nothing`, the default `httpVersion` can be assumed.

getResponseVersion :: Response a -> Maybe String

`getResponseVersion rsp` returns the HTTP protocol version of the response `rsp`. If `Nothing`, the default `httpVersion` can be assumed.

setRequestVersion :: String -> Request a -> Request a

`setRequestVersion v req` returns a new request, identical to `req`, but with its HTTP version set to `v`.

setResponseVersion :: String -> Response a -> Response a

`setResponseVersion v rsp` returns a new response, identical to `rsp`, but with its HTTP version set to `v`.

failHTTPS :: Monad m => URI -> m ()