mirror of
https://github.com/jgm/pandoc.git
synced 2026-08-30 17:59:17 +08:00
Albert Krewinkel
55 lines
1.7 KiB
Haskell
55 lines
1.7 KiB
Haskell
{- |
|
|
Module : Text.Pandoc.CSS
|
|
Copyright : © 2006-2022 John MacFarlane <jgm@berkeley.edu>,
|
|
2015-2016 Mauro Bieg,
|
|
2015 Ophir Lifshitz <hangfromthefloor@gmail.com>
|
|
License : GNU GPL, version 2 or above
|
|
|
|
Maintainer : John MacFarlane <jgm@berkeley@edu>
|
|
Stability : alpha
|
|
Portability : portable
|
|
|
|
Tools for working with CSS.
|
|
-}
|
|
module Text.Pandoc.CSS
|
|
( cssAttributes
|
|
, pickStyleAttrProps
|
|
, pickStylesToKVs
|
|
)
|
|
where
|
|
|
|
import Data.Either (fromRight)
|
|
import Data.Maybe (mapMaybe, listToMaybe)
|
|
import Data.Text (Text, pack)
|
|
import Text.Pandoc.Shared (trim)
|
|
import Text.Parsec
|
|
import Text.Parsec.Text
|
|
|
|
ruleParser :: Parser (Text, Text)
|
|
ruleParser = do
|
|
p <- many1 (noneOf ":") <* char ':'
|
|
v <- many1 (noneOf ":;") <* optional (char ';') <* spaces
|
|
return (trim $ pack p, trim $ pack v)
|
|
|
|
styleAttrParser :: Parser [(Text, Text)]
|
|
styleAttrParser = many1 ruleParser
|
|
|
|
-- | Parses a style string, returning the CSS attributes.
|
|
-- Returns an empty list on failure.
|
|
cssAttributes :: Text -> [(Text, Text)]
|
|
cssAttributes styleString =
|
|
fromRight [] $ parse styleAttrParser "" styleString
|
|
|
|
-- | takes a list of keys/properties and a CSS string and
|
|
-- returns the corresponding key-value-pairs.
|
|
pickStylesToKVs :: [Text] -> Text -> [(Text, Text)]
|
|
pickStylesToKVs props styleAttr =
|
|
filter (\s -> fst s `elem` props) $ cssAttributes styleAttr
|
|
|
|
-- | takes a list of key/property synonyms and a CSS string and maybe
|
|
-- returns the value of the first match (in order of the supplied list)
|
|
pickStyleAttrProps :: [Text] -> Text -> Maybe Text
|
|
pickStyleAttrProps lookupProps styleAttr = do
|
|
styles <- either (const Nothing) Just $ parse styleAttrParser "" styleAttr
|
|
listToMaybe $ mapMaybe (`lookup` styles) lookupProps
|