curl-aeson (empty) → 0.0.3

raw patch · 4 files changed

+239/−0 lines, 4 filesdep +aesondep +basedep +bytestringsetup-changed

Dependencies added: aeson, base, bytestring, curl, text

Files

LICENSE +24/−0
Setup.hs +2/−0
curl-aeson.cabal +38/−0
src/Network/Curl/Aeson.hs +175/−0

+ LICENSE view

@@ -0,0 +1,24 @@+Copyright (c) 2013, Joel Lehtonen+All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:+    * Redistributions of source code must retain the above copyright+      notice, this list of conditions and the following disclaimer.+    * Redistributions in binary form must reproduce the above copyright+      notice, this list of conditions and the following disclaimer in the+      documentation and/or other materials provided with the distribution.+    * Neither the name of the <organization> nor the+      names of its contributors may be used to endorse or promote products+      derived from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE+DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+ Setup.hs view

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

+ curl-aeson.cabal view

@@ -0,0 +1,38 @@+name:          curl-aeson+version:       0.0.3+synopsis:      Communicate with HTTP service using JSON +description:   A library for communicating with JSON over HTTP connection.+	       Supports rich set of HTTP connectivity features provided by+	       libcurl combined to the performance and elegancy of aeson.+	       .+	       All HTTP methods are supported. Instances of 'ToJSON' and+	       'FromJSON' typeclasses can be transferred via this library.+	       Session cookies and other HTTP options may be passed to libcurl+	       if needed.+	       .+	       This library is at its best when communicating with simple,+	       non-standardized JSON interfaces. If you are implementing+	       JSON-RPC compliant client or server, take a look at+	       <http://hackage.haskell.org/package/jmacro-rpc>.+category:      Network, Web, JSON+license:       BSD3+license-file:  LICENSE+author:        Joel Lehtonen+maintainer:    joel.lehtonen+curlaeson@iki.fi+homepage:      https://github.com/zouppen/haskell-curl-aeson+build-type:    Simple+cabal-version: >= 1.6++library+  hs-source-dirs:  src+  exposed-modules: Network.Curl.Aeson+  build-depends:+    aeson >= 0.6.0.0,+    base >= 4 && < 5,+    bytestring,+    curl >= 1.3.7,+    text++source-repository head+  type: git+  location: git://github.com/zouppen/haskell-curl-aeson.git

+ src/Network/Curl/Aeson.hs view

@@ -0,0 +1,175 @@+{-# LANGUAGE DeriveDataTypeable, RecordWildCards #-}+-- |+-- Module    : Network.Curl.Aeson+-- Copyright : (c) 2013, Joel Lehtonen+-- License   : BSD3+--+-- Maintainer: Joel Lehtonen <joel.lehtonen+curlaeson@iki.fi>+-- Stability : experimental+-- Portability: portable+--+-- Functions for communicating with JSON over HTTP connection.++module Network.Curl.Aeson+       ( -- * How to use this library+         -- $use+         +         -- * Sending HTTP request+         curlAesonGet+       , curlAesonGetWith+       , curlAeson+         -- * Helper functions+       , cookie+       , rawJson+       , (...)+       , noData+         -- * Exception handling+       , CurlAesonException(..)+       ) where++import Control.Exception+import Control.Monad+import Data.Aeson+import Data.Aeson.Types+import Data.ByteString.Lazy.Char8 (pack,unpack)+import Data.Maybe+import Data.Text (Text)+import Data.Typeable+import Network.Curl++-- | Shorthand for doing just a HTTP GET request and parsing the output to+-- any FromJSON instance.+curlAesonGet :: (FromJSON a) => URLString -> IO a+curlAesonGet = curlAesonGetWith parseJSON++-- | Shorthand for doing just a HTTP GET request and parsing the+-- output with given parser /p/.+curlAesonGetWith :: (Value -> Parser a) -> URLString -> IO a+curlAesonGetWith p url = curlAeson p "GET" url [] noData++-- | Send single HTTP request.+-- +-- The request automatically has @Content-type: application/json@+-- header if you pass any data. This function is lenient on response+-- content type: everything is accepted as long as it is parseable+-- with 'decode'.+-- +-- If you need authentication, you need to pass session cookie or+-- other means of authentication tokens via 'CurlOption' list.+curlAeson ::+  (ToJSON a)+  => (Value -> Parser b) -- ^ Parser for response. Use 'parseJSON' if+                         -- you like want to use FromJSON instance or+                         -- 'pure' if you want it in AST format.+  -> String              -- ^ Request method+  -> URLString           -- ^ Request URL+  -> [CurlOption]        -- ^ Session cookies, or other cURL+                         -- options. Use empty list if you don't need+                         -- any.+  -> Maybe a             -- ^ JSON data to send, or Nothing when+                         -- sending request without any content.+  -> IO b                -- ^ Received JSON data+curlAeson parser method url extraOpts maybeContent = do+  (curlCode,received) <- curlGetString url curlOpts+  when (curlCode /= CurlOK) $ throw CurlAesonException{errorMsg="HTTP error",..}+  let ast = case decode $ pack received of+        Nothing -> throw CurlAesonException{errorMsg="JSON parsing failed",..}+        Just x  -> x+  return $ case parseEither parser ast of+    Left errorMsg -> throw CurlAesonException{..}+    Right x -> x+  where+    curlOpts = commonOpts++dataOpts++extraOpts+    commonOpts = [CurlCustomRequest method]+    dataOpts = case maybeContent of+      Nothing -> []+      Just a  -> [CurlPostFields [unpack $ encode a]+                 ,CurlHttpHeaders ["Content-type: application/json"]+                 ]++-- | Helper function for writing parsers for JSON objects which are+-- not needed to be parsed completely.+--+-- In this example we are parsing JSON from+-- <http://json.org/example.html>.  Note the use of the+-- @OverloadedStrings@ language extension which enables 'Text' values+-- to be written as string literals.+--+-- @p ('Object' o) = 'pure' obj'...'\"glossary\"'...'\"title\"+--p _ = 'mzero'+-- @+(...) :: FromJSON b+         => Parser Object -- ^ Parser to JSON object to look into+         -> Text          -- ^ Key to look for+         -> Parser b      -- ^ Parser to the resulting field+(...) p s = do+  o <- p+  o .: s++-- Precedence should be higher than >> and >>= but lower than +++infixl 4 ...++-- | Single cookie of given key and value.+cookie :: String -> String -> CurlOption+cookie key value = CurlCookie $ key++"="++value++-- | Useful for just giving the JSON as string when it is static+-- anyway and doesn't need to be programmatically crafted.+rawJson :: String -> Maybe Value+rawJson = decode . pack++-- |To avoid ambiguity in type checker you may pass this value instead+-- of Nothing to 'curlAeson'.+noData :: Maybe Value+noData = Nothing++-- | This exception is is thrown when Curl doesn't finish cleanly or+-- the parsing of JSON response fails.+data CurlAesonException = CurlAesonException { url      :: URLString+                                             , curlCode :: CurlCode+                                             , curlOpts :: [CurlOption]+                                             , received :: String+                                             , errorMsg :: String+                                             } deriving (Show, Typeable)+instance Exception CurlAesonException++-- $use+--+-- To get bid and ask levels as a pair from a Bitcoin exchange using its public+-- API:+--+-- @{-\# LANGUAGE OverloadedStrings #-}+--import Control.Monad+--import Data.Aeson+--import Network.Curl.Aeson+--+--ticker :: 'IO' ('Double','Double')+--ticker = 'curlAesonGetWith' p \"https:\/\/bitcoin-central.net\/api\/v1\/ticker\/eur\"+--  where+--    p ('Object' o) = do+--      bid <- o '.:' \"bid\"+--      ask <- o '.:' \"ask\"+--      'return' (bid,ask)+--    p _ = 'mzero'+-- @+-- +-- The same as above, but we define our own data type which is an+-- instance of FromJSON:+-- +-- @{-\# LANGUAGE OverloadedStrings #-}+--import Control.Applicative+--import Control.Monad+--import Data.Aeson+--import Network.Curl.Aeson+--+--data Ticker = Ticker { bid :: 'Double'+--                     , ask :: 'Double'+--                     } deriving ('Show')+--+--instance 'FromJSON' Ticker where+--    parseJSON ('Object' o) = Ticker '<$>' o '.:' \"bid\" '<*>' o '.:' \"ask\"+--    parseJSON _ = 'mzero'+--+--ticker :: 'IO' Ticker+--ticker = 'curlAesonGet' \"https:\/\/bitcoin-central.net\/api\/v1\/ticker\/eur\"+-- @