clay-0.8: src/Clay/Render.hs
{-# LANGUAGE OverloadedStrings #-}
module Clay.Render
( Config (..)
, pretty
, compact
, render
, putCss
, renderWith
)
where
import Control.Applicative
import Control.Monad.Writer
import Data.Either
import Data.Foldable (foldMap)
import Data.List (sort)
import Data.Maybe
import Data.Text (Text)
import Data.Text.Lazy.Builder
import Prelude hiding ((**))
import qualified Data.Text as Text
import qualified Data.Text.Lazy as Lazy
import qualified Data.Text.Lazy.IO as Lazy
import Clay.Stylesheet hiding (Child, query)
import Clay.Property
import Clay.Selector
import qualified Clay.Stylesheet as Rule
data Config = Config
{ indentation :: Builder
, newline :: Builder
, sep :: Builder
, finalSemicolon :: Bool
, warn :: Bool
, align :: Bool
, banner :: Bool
}
-- | Configuration to print to a pretty human readable CSS output.
pretty :: Config
pretty = Config
{ indentation = " "
, newline = "\n"
, sep = " "
, finalSemicolon = True
, warn = True
, align = True
, banner = True
}
-- | Configuration to print to a compacted unreadable CSS output.
compact :: Config
compact = Config
{ indentation = ""
, newline = ""
, sep = ""
, finalSemicolon = False
, warn = False
, align = False
, banner = False
}
-- | Render to CSS using the default configuration (`pretty`) and directly
-- print to the standard output.
putCss :: Css -> IO ()
putCss = Lazy.putStr . render
-- | Render a stylesheet with the default configuration. The pretty printer is
-- used by default.
render :: Css -> Lazy.Text
render = renderWith pretty
-- | Render a stylesheet with a custom configuration and an optional outer
-- scope.
renderWith :: Config -> Css -> Lazy.Text
renderWith cfg (S c)
= renderBanner cfg
. toLazyText
. cssRules cfg
. flattenRules
. execWriter
$ c
-------------------------------------------------------------------------------
-- | The AST of a CSS3 file.
data Css3
= Css3Query MediaQuery [Css3]
| Css3Rule [App] [(Key (), Value)]
| Css3Font [(Key (), Value)]
flattenRules :: [Rule] -> [Css3]
flattenRules rules =
let
property p = case p of
Property k v -> (k, v)
_ -> error "only properties are allowed in @font-face"
nestApp app css = case css of
Css3Query q cs -> Css3Query q $ map (nestApp app) cs
Css3Rule as ps -> Css3Rule (app:as) ps
Css3Font ps -> Css3Font ps
(props, nests, qrys, faces) = foldr
(\r (ps,ns,qs,fs) -> case r of
Property k v -> ((k, v):ps, ns, qs, fs)
Nested a rs' -> ( ps, (a, rs'):ns, qs, fs)
Query q rs' -> ( ps, ns, (q, rs'):qs, fs)
Face rs' -> ( ps, ns, qs, rs':fs))
([],[],[],[])
rules
in
(if null props then [] else [Css3Rule [] props]) ++
concatMap (\(app, rs') -> map (nestApp app) (flattenRules rs')) nests ++
map (\(q, rs') -> Css3Query q (flattenRules rs')) qrys ++
map (\ rs' -> Css3Font $ map property rs') faces
-------------------------------------------------------------------------------
renderBanner :: Config -> Lazy.Text -> Lazy.Text
renderBanner cfg =
if banner cfg
then (<> "\n/* Generated with Clay, http://fvisser.nl/clay */")
else id
-------------------------------------------------------------------------------
mediaQuery :: MediaQuery -> Builder
mediaQuery (MediaQuery no ty fs) = mconcat
[ "@media "
, case no of
Nothing -> ""
Just Not -> "not "
Just Only -> "only "
, mediaType ty
, mconcat ((" and " <>) . feature <$> fs)
]
mediaType :: MediaType -> Builder
mediaType (MediaType (Value v)) = fromText (plain v)
feature :: Feature -> Builder
feature (Feature k mv) =
case mv of
Nothing -> fromText k
Just (Value v) -> mconcat
[ "(" , fromText k , ": " , fromText (plain v) , ")" ]
cssRules :: Config -> [Css3] -> Builder
cssRules cfg = (mconcat .) $ map $ \c -> mconcat $ case c of
Css3Query q cs -> [ mediaQuery q, block $ cssRules cfg cs ]
Css3Rule sel ps -> [ selector cfg (merger $ reverse sel), propertyBlock ps ]
Css3Font ps -> [ "@font-face", propertyBlock ps ]
where
propertyBlock = block . properties cfg . concatMap collect
block inner = mconcat [ nl, "{", nl, inner, "}", nl, nl ]
nl = newline cfg
merger :: [App] -> Selector
merger [] = "" -- error "this should be fixed!"
merger (x:xs) =
case x of
Rule.Child s -> case xs of [] -> s; _ -> merger xs |> s
Sub s -> case xs of [] -> s; _ -> merger xs ** s
Root s -> s ** merger xs
Pop i -> merger (drop i (x:xs))
Self f -> case xs of [] -> star `with` f; _ -> merger xs `with` f
collect :: (Key (), Value) -> [Either Text (Text, Text)]
collect (Key ky, Value vl) =
case (ky, vl) of
( Plain k , Plain v ) -> [prop k v]
( Prefixed ks , Plain v ) -> flip map ks $ \(p, k) -> prop (p <> k) v
( Plain k , Prefixed vs ) -> flip map vs $ \(p, v) -> prop k (p <> v)
( Prefixed ks , Prefixed vs ) -> flip map ks $ \(p, k) -> (Left (p <> k) `maybe` (prop (p <> k) . mappend p)) (lookup p vs)
where prop k v = Right (k, v)
properties :: Config -> [Either Text (Text, Text)] -> Builder
properties cfg xs =
let width = 1 + maximum (Text.length . fst <$> rights xs)
ind = indentation cfg
new = newline cfg
finalSemi = if finalSemicolon cfg then ";" else ""
in (<> new) $ (<> finalSemi) $ intersperse (";" <> new) $ flip map xs $ \p ->
case p of
Left w -> if warn cfg then ind <> "/* no value for " <> fromText w <> " */" <> new else mempty
Right (k, v) ->
let pad = if align cfg then fromText (Text.replicate (width - Text.length k) " ") else ""
in mconcat [ind, fromText k, pad, ":", sep cfg, fromText v]
selector :: Config -> Selector -> Builder
selector cfg = intersperse ("," <> newline cfg) . rec
where rec (In (SelectorF (Refinement ft) p)) = (<> foldMap predicate (sort ft)) <$>
case p of
Star -> if null ft then ["*"] else [""]
Elem t -> [fromText t]
Child a b -> ins " > " <$> rec a <*> rec b
Deep a b -> ins " " <$> rec a <*> rec b
Adjacent a b -> ins " + " <$> rec a <*> rec b
Combined a b -> rec a ++ rec b
where ins s a b = a <> s <> b
predicate :: Predicate -> Builder
predicate ft = mconcat $
case ft of
Id a -> [ "#", fromText a ]
Class a -> [ ".", fromText a ]
Attr a -> [ "[", fromText a, "]" ]
AttrVal a v -> [ "[", fromText a, "='", fromText v, "']" ]
AttrEnds a v -> [ "[", fromText a, "$='", fromText v, "']" ]
AttrSpace a v -> [ "[", fromText a, "~='", fromText v, "']" ]
AttrHyph a v -> [ "[", fromText a, "|='", fromText v, "']" ]
Pseudo a -> [ ":", fromText a ]
PseudoFunc a p -> [ ":", fromText a, "(", intersperse "," (map fromText p), ")" ]