1 {-# LANGUAGE DoAndIfThenElse #-}
6 import qualified Data.ByteString as B (hPut)
19 import Network.Curl.Download (openURI)
20 import System.Directory (doesFileExist, getTemporaryDirectory)
21 import System.IO (hPutStrLn, stderr)
22 import System.IO.Temp (openBinaryTempFile)
24 import LWN.URI (filename)
26 login_url :: URLString
27 login_url = "https://lwn.net/login"
29 username_field :: String
30 username_field = "Username"
32 password_field :: String
33 password_field = "Password"
35 submit_field :: String
36 submit_field = "submit"
39 default_curl_opts :: [CurlOption]
41 [ -- The Global cache is not thread-friendly.
42 CurlDNSUseGlobalCache False,
44 -- And we don't want to use a DNS cache anyway.
45 CurlDNSCacheTimeout 0,
47 -- Give it a little time...
50 -- And let us know when things go wrong.
55 get_page :: Maybe FilePath -> URLString -> IO (Maybe String)
56 get_page cookie_jar url =
58 -- Create a curl instance.
61 -- Perform the request, and get back a CurlResponse object.
62 -- The cast is needed to specify how we would like our headers
63 -- and body returned (Strings).
64 resp <- do_curl_ curl url curl_opts :: IO CurlResponse
66 -- Pull out the response code as a CurlCode.
67 let code = respCurlCode resp
70 CurlOK -> return $ Just (respBody resp)
72 hPutStrLn stderr ("HTTP Error: " ++ (show error_code))
73 -- If an error occurred, we want to dump as much information as
74 -- possible. If this becomes a problem, we can use respGetInfo to
75 -- query the response object for more information
81 Just cookies -> [ CurlCookieJar cookies ]
83 curl_opts = default_curl_opts ++ get_opts
86 log_in :: FilePath -> String -> String -> IO Bool
87 log_in cookie_jar username password =
89 -- Create a curl instance.
92 -- Perform the request, and get back a CurlResponse object.
93 -- The cast is needed to specify how we would like our headers
94 -- and body returned (Strings).
95 resp <- do_curl_ curl login_url curl_opts :: IO CurlResponse
97 -- Pull out the response code as a CurlCode.
98 let code = respCurlCode resp
101 CurlOK -> return True
103 hPutStrLn stderr ("HTTP Error: " ++ (show error_code))
104 -- If an error occurred, we want to dump as much information as
105 -- possible. If this becomes a problem, we can use respGetInfo to
106 -- query the response object for more information
109 post_submit :: String
110 post_submit = submit_field ++ "=Log+In"
112 post_username :: String
113 post_username = username_field ++ "=" ++ username
115 post_password :: String
116 post_password = password_field ++ "=" ++ password
118 post_data :: [String]
119 post_data = [post_username, post_password, post_submit]
121 post_opts :: [CurlOption]
123 [ CurlCookieSession True,
124 CurlCookieJar cookie_jar,
126 CurlPostFields post_data ]
128 curl_opts :: [CurlOption]
129 curl_opts = default_curl_opts ++ post_opts
132 -- | Save the image at 'url'. Saves to a temporary file, and
133 -- returns the path to that file if successful. Otherwise,
134 -- returns 'Nothing'.
136 -- We need to be able to parse the filename out of the URL
137 -- so that when we stick our image in the document, the reader
138 -- knows that type (jpg, png, etc.) it is.
139 save_image :: URLString -> IO (Maybe FilePath)
141 it_exists <- doesFileExist url
143 -- It's local, just use it.
146 let fn = filename url
148 Nothing -> return Nothing
150 temp_dir <- getTemporaryDirectory
151 (out_path, out_handle) <- openBinaryTempFile temp_dir file
152 result <- openURI url
155 hPutStrLn stderr ("HTTP Error: " ++ err)
159 return $ Just out_path