{-# LANGUAGE OverloadedStrings #-} {- Copyright (C) 2011-2015 John MacFarlane This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -} {- | Module : Text.Pandoc.SelfContained Copyright : Copyright (C) 2011-2015 John MacFarlane License : GNU GPL, version 2 or above Maintainer : John MacFarlane Stability : alpha Portability : portable Functions for converting an HTML file into one that can be viewed offline, by incorporating linked images, CSS, and scripts into the HTML using data URIs. -} module Text.Pandoc.SelfContained ( makeSelfContained ) where import Text.HTML.TagSoup import Network.URI (isURI, escapeURIString, URI(..), parseURI) import Data.ByteString.Base64 import qualified Data.ByteString.Char8 as B import Data.ByteString (ByteString) import System.FilePath (takeExtension, takeDirectory, ()) import Data.Char (toLower, isAscii, isAlphaNum) import Codec.Compression.GZip as Gzip import qualified Data.ByteString.Lazy as L import Text.Pandoc.Shared (renderTags', err, fetchItem', warn, trim) import Text.Pandoc.MediaBag (MediaBag) import Text.Pandoc.MIME (MimeType) import Text.Pandoc.UTF8 (toString) import Text.Pandoc.Options (WriterOptions(..)) import Data.List (isPrefixOf) import Control.Applicative import Text.Parsec (runParserT, ParsecT) import qualified Text.Parsec as P import Control.Monad.Trans (lift) isOk :: Char -> Bool isOk c = isAscii c && isAlphaNum c makeDataURI :: String -> ByteString -> String makeDataURI mime raw = if textual then "data:" ++ mime' ++ "," ++ escapeURIString isOk (toString raw) else "data:" ++ mime' ++ ";base64," ++ toString (encode raw) where textual = "text/" `Data.List.isPrefixOf` mime mime' = if textual && ';' `notElem` mime then mime ++ ";charset=utf-8" else mime -- mime type already has charset convertTag :: MediaBag -> Maybe String -> Tag String -> IO (Tag String) convertTag media sourceURL t@(TagOpen tagname as) | tagname `elem` ["img", "embed", "video", "input", "audio", "source", "track"] = do as' <- mapM processAttribute as return $ TagOpen tagname as' where processAttribute (x,y) = if x == "src" || x == "href" || x == "poster" then do enc <- getDataURI media sourceURL (fromAttrib "type" t) y return (x, enc) else return (x,y) convertTag media sourceURL t@(TagOpen "script" as) = case fromAttrib "src" t of [] -> return t src -> do enc <- getDataURI media sourceURL (fromAttrib "type" t) src return $ TagOpen "script" (("src",enc) : [(x,y) | (x,y) <- as, x /= "src"]) convertTag media sourceURL t@(TagOpen "link" as) = case fromAttrib "href" t of [] -> return t src -> do enc <- getDataURI media sourceURL (fromAttrib "type" t) src return $ TagOpen "link" (("href",enc) : [(x,y) | (x,y) <- as, x /= "href"]) convertTag _ _ t = return t cssURLs :: MediaBag -> Maybe String -> FilePath -> ByteString -> IO ByteString cssURLs media sourceURL d orig = do res <- runParserT (parseCSSUrls media sourceURL d) () "css" orig case res of Left e -> warn ("Could not parse CSS: " ++ show e) >> return orig Right bs -> return bs parseCSSUrls :: MediaBag -> Maybe String -> FilePath -> ParsecT ByteString () IO ByteString parseCSSUrls media sourceURL d = B.concat <$> P.many (pCSSWhite <|> pCSSComment <|> pCSSUrl media sourceURL d <|> pCSSOther) -- Note: some whitespace in CSS is significant, so we can't collapse it! pCSSWhite :: ParsecT ByteString () IO ByteString pCSSWhite = B.singleton <$> P.space <* P.spaces pCSSComment :: ParsecT ByteString () IO ByteString pCSSComment = P.try $ do P.string "/*" P.manyTill P.anyChar (P.try (P.string "*/")) return B.empty pCSSOther :: ParsecT ByteString () IO ByteString pCSSOther = do (B.pack <$> P.many1 (P.noneOf "u/ \n\r\t")) <|> (B.singleton <$> P.char 'u') <|> (B.singleton <$> P.char '/') pCSSUrl :: MediaBag -> Maybe String -> FilePath -> ParsecT ByteString () IO ByteString pCSSUrl media sourceURL d = P.try $ do P.string "url(" P.spaces quote <- P.option Nothing (Just <$> P.oneOf "\"'") url <- P.manyTill P.anyChar (maybe (P.lookAhead (P.char ')')) P.char quote) P.spaces P.char ')' let fallback = B.pack ("url(" ++ maybe "" (:[]) quote ++ trim url ++ maybe "" (:[]) quote ++ ")") case trim url of '#':_ -> return fallback 'd':'a':'t':'a':':':_ -> return fallback u -> do let url' = if isURI u then u else d u enc <- lift $ getDataURI media sourceURL "" url' return (B.pack enc) getDataURI :: MediaBag -> Maybe String -> MimeType -> String -> IO String getDataURI _ _ _ src@('d':'a':'t':'a':':':_) = return src -- already data: uri getDataURI media sourceURL mimetype src = do let ext = map toLower $ takeExtension src fetchResult <- fetchItem' media sourceURL src (raw, respMime) <- case fetchResult of Left msg -> err 67 $ "Could not fetch " ++ src ++ "\n" ++ show msg Right x -> return x let raw' = if ext == ".gz" then B.concat $ L.toChunks $ Gzip.decompress $ L.fromChunks $ [raw] else raw let mime = case (mimetype, respMime) of ("",Nothing) -> error $ "Could not determine mime type for `" ++ src ++ "'" (x, Nothing) -> x (_, Just x ) -> x let cssSourceURL = case parseURI src of Just u | uriScheme u `elem` ["http:","https:"] -> Just $ show u{ uriPath = "", uriQuery = "", uriFragment = "" } _ -> Nothing result <- if mime == "text/css" then cssURLs media cssSourceURL (takeDirectory src) raw' else return raw' return $ makeDataURI mime result -- | Convert HTML into self-contained HTML, incorporating images, -- scripts, and CSS using data: URIs. makeSelfContained :: WriterOptions -> String -> IO String makeSelfContained opts inp = do let tags = parseTags inp out' <- mapM (convertTag (writerMediaBag opts) (writerSourceURL opts)) tags return $ renderTags' out'