--- |Functions and data for working with Twitter statuses.
+{-# LANGUAGE NoMonomorphismRestriction #-}
+
+-- | Functions and data for working with Twitter statuses.
module Twitter.Status
where
-import Data.Maybe
+import Control.Applicative ((<$>), (<*>))
+import Control.Monad (liftM)
+import Data.Aeson ((.:), FromJSON(..), Value(Object))
+import Data.Maybe (fromMaybe, mapMaybe, isJust)
+import Data.Monoid (mempty)
import Data.String.Utils (join, splitWs)
+import Data.Text (pack)
+import Data.Time (formatTime)
+import Data.Time.Clock (UTCTime)
+import Data.Time.Format (parseTime)
+import Data.Time.LocalTime (TimeZone, utcToZonedTime)
+import System.Locale (defaultTimeLocale, rfc822DateFormat)
import Test.HUnit
import Text.Regex (matchRegex, mkRegex)
-import Text.XML.HaXml
import StringUtils (listify)
import Twitter.User
-import Twitter.Xml
-
--- |Represents one Twitter status. We don't care about any of their
--- other properties.
-data Status = Status { status_id :: Integer,
- created_at :: String,
- text :: String,
- user :: User }
- deriving (Show, Eq)
-
-
--- |Given some XML content, create a 'Status' from it.
-status_from_content :: Content -> (Maybe Status)
-status_from_content content =
-
- if (length status_ids) == 0
- || (length created_ats) == 0
- || (length texts) == 0
- || (length users) == 0
- then
- Nothing
- else
- case first_status_id of
- Nothing -> Nothing
- (Just status_id_data) ->
- case first_created_at of
- Nothing -> Nothing
- (Just created_at_data) ->
- case first_user of
- Nothing -> Nothing
- (Just user_object) ->
- case (reads status_id_data :: [(Integer, String)]) of
- [] -> Nothing
- parseresult:_ -> Just (Status (fst parseresult) created_at_data all_text user_object)
+data Status = Status {
+ created_at :: Maybe UTCTime,
+ status_id :: Integer,
+ reply :: Bool,
+ retweeted :: Bool,
+ text :: String,
+ user :: User
+ } deriving (Show, Eq)
+
+type Timeline = [Status]
+
+instance FromJSON Status where
+ parseJSON (Object t) =
+ Status <$>
+ liftM parse_status_time (t .: created_at_field) <*>
+ (t .: id_field) <*>
+ liftM isJustInt (t .: in_reply_to_status_id_field) <*>
+ (t .: retweeted_field) <*>
+ (t .: text_field) <*>
+ (t .: user_field)
where
- status_ids = (unique_id content)
- first_status_id = get_char_data (status_ids !! 0)
-
- created_ats = (status_created_at content)
- first_created_at = get_char_data (created_ats !! 0)
-
- texts = (status_text content)
- all_text = concat $ catMaybes (map get_char_data texts)
-
- users = (status_user content)
- first_user = user_from_content (users !! 0)
-
-
--- |Takes an XML String as an argument, and returns the
--- status that was parsed from it. Should only be used
--- on XML string where a <status> is a top-level element.
-parse_status :: String -> [Status]
-parse_status xml_data =
- catMaybes maybe_status
- where
- (Document _ _ root _) = xmlParse xml_file_name xml_data
- root_elem = CElem root
- status_element = (single_status root_elem)
- maybe_status = map status_from_content status_element
+ -- The typechecker flips out without this.
+ isJustInt :: Maybe Int -> Bool
+ isJustInt = isJust
+
+ created_at_field = pack "created_at"
+ id_field = pack "id"
+ in_reply_to_status_id_field = pack "in_reply_to_status_id"
+ retweeted_field = pack "retweeted"
+ text_field = pack "text"
+ user_field = pack "user"
+
+ -- Do whatever.
+ parseJSON _ = mempty
+
+parse_status_time :: String -> Maybe UTCTime
+parse_status_time =
+ parseTime defaultTimeLocale status_format
+ where
+ -- | Should match e.g. "Sun Oct 24 18:21:41 +0000 2010"
+ status_format :: String
+ status_format = "%a %b %d %H:%M:%S %z %Y"
+
+utc_time_to_rfc822 :: Maybe TimeZone -> UTCTime -> String
+utc_time_to_rfc822 mtz utc =
+ case mtz of
+ Nothing -> foo utc
+ Just tz -> foo $ utcToZonedTime tz utc
+ where
+ foo = formatTime defaultTimeLocale rfc822DateFormat
+
+
+show_created_at :: Maybe TimeZone -> Status -> String
+show_created_at mtz =
+ (fromMaybe "") . (fmap $ utc_time_to_rfc822 mtz) . created_at
+
+-- | Returns a nicely-formatted String representing the given 'Status'
+-- object.
+pretty_print :: Maybe TimeZone -> Status -> String
+pretty_print mtz status =
+ concat [ name,
+ " - ",
+ sca,
+ "\n",
+ replicate bar_length '-',
+ "\n",
+ text status,
+ "\n\n",
+ join "\n" user_timeline_urls,
+ "\n" ]
+ where
+ sca = show_created_at mtz status
+ name = screen_name (user status)
+ user_timeline_urls = listify (make_user_timeline_urls status)
+ bar_length = (length name) + 3 + (length sca)
--- |Takes an XML String as an argument, and returns the list of
--- statuses that can be parsed from it.
-parse_statuses :: String -> [Status]
-parse_statuses xml_data =
- catMaybes maybe_statuses
- where
- (Document _ _ root _) = xmlParse xml_file_name xml_data
- root_elem = CElem root
- status_elements = (all_statuses root_elem)
- maybe_statuses = map status_from_content status_elements
-
-
--- |This is a required parameter to the xmlParse function used in
--- error reporting. We're not parsing a function, though, so we leave
--- it blank.
-xml_file_name :: String
-xml_file_name = ""
-
--- |Returns a nicely-formatted String representing the given 'Status'
--- object.
-pretty_print :: Status -> String
-pretty_print status =
- concat [ name,
- " - ",
- (created_at status),
- "\n",
- replicate ((length name) + 3 + (length (created_at status))) '-',
- "\n",
- replace_entities (text status),
- "\n\n",
- join "\n" user_timeline_urls,
- "\n" ]
- where
- name = screen_name (user status)
- user_timeline_urls = listify (make_user_timeline_urls status)
-
-
--- |Given a list of statuses, returns the greatest status_id belonging
--- to one of the statuses in the list.
-get_max_status_id :: [Status] -> Integer
+-- | Given a list of statuses, returns the greatest status_id
+-- belonging to one of the statuses in the list.
+get_max_status_id :: Timeline -> Integer
get_max_status_id statuses =
maximum status_ids
where
status_ids = map status_id statuses
--- |Parse one username from a word.
+-- | Parse one username from a word.
parse_username :: String -> Maybe String
parse_username word =
- case matches of
- Nothing -> Nothing
- Just [] -> Nothing
- Just (first_match:_) -> Just first_match
- where
- username_regex = mkRegex "@([a-zA-Z0-9_]+)"
- matches = matchRegex username_regex word
+ case matches of
+ Nothing -> Nothing
+ Just [] -> Nothing
+ Just (first_match:_) -> Just first_match
+ where
+ username_regex = mkRegex "@([a-zA-Z0-9_]+)"
+ matches = matchRegex username_regex word
--- |Parse all usernames of the form @username from a status.
+-- | Parse all usernames of the form \@username from a status.
parse_usernames_from_status :: Status -> [String]
parse_usernames_from_status status =
- catMaybes (map parse_username status_words)
- where
- status_words = splitWs (text status)
+ mapMaybe parse_username status_words
+ where
+ status_words = splitWs (text status)
--- |Get all referenced users' timeline URLs.
+-- | Get all referenced users' timeline URLs.
make_user_timeline_urls :: Status -> [String]
make_user_timeline_urls status =
- map screen_name_to_timeline_url usernames
- where
- usernames = parse_usernames_from_status status
+ map screen_name_to_timeline_url usernames
+ where
+ usernames = parse_usernames_from_status status
status_tests :: [Test]
test_parse_usernames :: Test
test_parse_usernames =
- TestCase $ assertEqual "All usernames are parsed." expected_usernames actual_usernames
+ TestCase $
+ assertEqual
+ "All usernames are parsed."
+ expected_usernames
+ actual_usernames
where
dummy_user = User { screen_name = "nobody" }
dummy_status = Status { status_id = 1,
- created_at = "never",
+ created_at = Nothing,
text = "Hypothesis: @donsbot and @bonus500 are two personalities belonging to the same person.",
- user = dummy_user }
-
+ user = dummy_user,
+ reply = False,
+ retweeted = False
+ }
+
actual_usernames = parse_usernames_from_status dummy_status
expected_usernames = ["donsbot", "bonus500"]
projects / dead / halcyon.git / blobdiff