yesod/yesod-bin/AddHandler.hs
2013-04-03 16:15:16 +03:00

114 lines
3.0 KiB
Haskell

module AddHandler (addHandler) where
import Prelude hiding (readFile)
import System.IO (hFlush, stdout)
import Data.Char (isLower, toLower, isSpace)
import Data.List (isPrefixOf, isSuffixOf)
import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import System.Directory (getDirectoryContents)
-- strict readFile
readFile :: FilePath -> IO String
readFile = fmap T.unpack . TIO.readFile
addHandler :: IO ()
addHandler = do
allFiles <- getDirectoryContents "."
cabal <-
case filter (".cabal" `isSuffixOf`) allFiles of
[x] -> return x
[] -> error "No cabal file found"
_ -> error "Too many cabal files found"
putStr "Name of route (without trailing R): "
hFlush stdout
name <- getLine
case name of
[] -> error "Please provide a name"
c:_
| isLower c -> error "Name must start with an upper case letter"
| otherwise -> return ()
putStr "Enter route pattern (ex: /entry/#EntryId): "
hFlush stdout
pattern <- getLine
putStr "Enter space-separated list of methods (ex: GET POST): "
hFlush stdout
methods <- getLine
let modify fp f = readFile fp >>= writeFile fp . f
modify "Application.hs" $ fixApp name
modify cabal $ fixCabal name
modify "config/routes" $ fixRoutes name pattern methods
writeFile ("Handler/" ++ name ++ ".hs") $ mkHandler name pattern methods
fixApp :: String -> String -> String
fixApp name =
unlines . reverse . go . reverse . lines
where
l = "import Handler." ++ name
go [] = [l]
go (x:xs)
| "import Handler." `isPrefixOf` x = l : x : xs
| otherwise = x : go xs
fixCabal :: String -> String -> String
fixCabal name =
unlines . reverse . go . reverse . lines
where
l = "import Handler." ++ name
go [] = [l]
go (x:xs)
| "Handler." `isPrefixOf` x' = (spaces ++ "Handler." ++ name) : x : xs
| otherwise = x : go xs
where
(spaces, x') = span isSpace x
fixRoutes :: String -> String -> String -> String -> String
fixRoutes name pattern methods =
(++ l)
where
l = concat
[ pattern
, " "
, name
, "R "
, methods
, "\n"
]
mkHandler :: String -> String -> String -> String
mkHandler name pattern methods = unlines
$ ("module Handler." ++ name ++ " where")
: ""
: "import Import"
: concatMap go (words methods)
where
go method =
[ ""
, concat $ func : " :: " : map toArrow types ++ ["Handler Html"]
, concat
[ func
, " = error \"Not yet implemented: "
, func
, "\""
]
]
where
func = concat [map toLower method, name, "R"]
types = getTypes pattern
toArrow t = concat [t, " -> "]
getTypes "" = []
getTypes ('/':rest) = getTypes rest
getTypes ('#':rest) =
typ : getTypes rest'
where
(typ, rest') = break (== '/') rest
getTypes rest = getTypes $ dropWhile (/= '/') rest