Add OpenWeatherMap api

WeatherApi/OpenWeatherMap.hs

@@ -0,0 +1,71 @@
+{-# LANGUAGE OverloadedStrings #-}
+module WeatherApi.OpenWeatherMap (initApi) where
+
+import Network.HTTP
+import Network.URI
+import WeatherApi hiding (humidity)
+import Codec.Binary.UTF8.String (encodeString)
+import Data.ByteString.Char8 (pack, unpack)
+import Data.Aeson
+import Data.Aeson.TH
+import Data.Attoparsec.ByteString hiding (Result(..))
+import Data.Maybe
+
+import Control.Applicative
+import qualified Data.Vector as V
+
+import WeatherApi.Util
+
+apiUrl = "http://api.openweathermap.org/data/2.5/weather?"
+
+type ApiKey = String
+
+instance FromJSON Weather where
+  parseJSON (Object o) = do
+    Object m <- o .: "main"
+    Weather
+      <$> pure 0.0
+      <*> (m .: "temp")
+      <*> pure ""
+      <*> pure ""
+      <*> pure ""
+
+-- | Make config for use with WeatherApi functions
+initApi :: ApiKey -> Config
+initApi key =
+    let params = [("units", "metric"), ("appid", key)]
+        urn c  = urlEncodeVars $ params ++ [("q", encodeString c)]
+    in Config { apiHost  = "api.openweathermap.org"
+              , apiPort  = 80
+              , queryFun = makeQueryFun urn
+              }
+
+retrieve s urn =
+    case parseURI $ apiUrl ++ urn of
+      Nothing  -> return $ Left $ NetworkError "Invalid URL"
+      Just uri -> get s uri
+
+get s uri = do
+  eresp <- sendHTTP s (Request uri GET [] "")
+  case eresp of
+    Left err  -> return $ Left $ NetworkError $ show err
+    Right res -> return $ Right $ rspBody res
+
+-- | This return function witch will actualy retrieve and parse weather from stream
+makeQueryFun :: (String -> String)
+                -> (HandleStream String)
+                -> String
+                -> IO ApiResponse
+makeQueryFun q stream city =
+    do
+      resp <- retrieve stream $ q city
+      case resp of
+        Left err -> return $ Left err
+        Right c  -> do
+          case maybeResult $ parse json $ pack c of
+            Nothing -> return $ Left $ ParseError "Bad response"
+            Just v  ->
+              return $ case fromJSON v :: Result Weather of
+                Error e   -> Left $ ParseError $ "Can't parse data: " ++ e
+                Success v -> Right v
+

package.yaml

@@ -1,5 +1,5 @@
 name:        weather-api
-version:     "0.4.3.3"
+version:     "0.4.4"
 synopsis:    Weather API implemented in Haskell
 description: This library implement generic API for retrieving weather
              by HTTP, and has Google weather API as example.
@@ -14,6 +14,7 @@ library:
   exposed-modules:
     - WeatherApi
     - WeatherApi.WWOnline
+    - WeatherApi.OpenWeatherMap
   other-modules:
     - WeatherApi.Util
 dependencies: