src/PursLoader/Loader.purs

   1 module PursLoader.Loader
   2   ( Effects()
   3   , loader
   4   , loaderFn
   5   ) where
   6
   7 import Prelude (Unit(), ($), (>>=), (<$>), (<*>), (<<<), (++), bind, const)
   8
   9 import Control.Bind (join)
  10 import Control.Monad.Eff (Eff())
  11 import Control.Monad.Eff.Exception (Error(), error)
  12
  13 import Data.Array ((!!))
  14 import Data.Function (Fn2(), mkFn2)
  15 import Data.Maybe (Maybe(..), maybe)
  16 import Data.Either (either)
  17 import Data.Foreign (Foreign())
  18 import Data.Foreign.Class (read)
  19 import Data.Foreign.Null (runNull)
  20 import Data.String.Regex (Regex(), match, noFlags, regex)
  21
  22 import Unsafe.Coerce (unsafeCoerce)
  23
  24 import PursLoader.LoaderRef
  25   ( LoaderRef()
  26   , Loader()
  27   , async
  28   , cacheable
  29   , query
  30   , clearDependencies
  31   , addDependency
  32   , resourcePath
  33   )
  34
  35 import PursLoader.LoaderUtil (parseQuery)
  36 import PursLoader.Options (runOptions)
  37 import PursLoader.Path (dirname, relative)
  38
  39 type Effects eff = (loader :: Loader | eff)
  40
  41 type PurescriptWebpackPluginContext eff = { compile :: (Foreign -> Eff (Effects eff) Unit) -> Eff (Effects eff) Unit }
  42
  43 loader :: forall eff. LoaderRef -> String -> Eff (Effects eff) Unit
  44 loader ref source = do
  45   callback <- async ref
  46
  47   cacheable ref
  48
  49   let parsed = parseQuery $ query ref
  50
  51       options = either (const Nothing) (Just <<< runOptions) (read parsed)
  52
  53       moduleName = join $ match moduleRegex source >>= \as -> as !! 1
  54
  55       resourceDir = dirname (resourcePath ref)
  56
  57       modulePath = (\opts -> relative resourceDir opts.pscBundle) <$> options
  58
  59       result = (\path name -> "module.exports = require('" ++ path ++ "')['" ++ name ++ "'];") <$> modulePath <*> moduleName
  60
  61   clearDependencies ref
  62
  63   addDependency ref (resourcePath ref)
  64
  65   pluginContext.compile (\err -> maybe (callback (Just $ error "Failed to run loader") "")
  66                                        (callback (compileError err)) result)
  67   where
  68   moduleRegex :: Regex
  69   moduleRegex = regex "(?:^|\\n)module\\s+([\\w\\.]+)" noFlags { ignoreCase = true }
  70
  71   pluginContext :: PurescriptWebpackPluginContext eff
  72   pluginContext = (unsafeCoerce ref).purescriptWebpackPluginContext
  73
  74   compileError :: Foreign -> Maybe Error
  75   compileError value = either (const $ Just (error "Failed to compile")) ((<$>) error) (runNull <$> read value)
  76
  77 loaderFn :: forall eff. Fn2 LoaderRef String (Eff (Effects eff) Unit)
  78 loaderFn = mkFn2 loader