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')
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.CSS.Parse (parseNestedBlocks, NestedBlock(..))
import Text.CSS.Render (renderNestedBlocks)
import Data.Text.Encoding (decodeUtf8, encodeUtf8)
import qualified Data.Text as T
import Data.Text (Text)
import Data.Text.Lazy (toStrict)
import Data.Text.Lazy.Builder (toLazyText)
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
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
case parseNestedBlocks (decodeUtf8 orig) of
Left _err -> return orig
Right bs -> (encodeUtf8 . toStrict . toLazyText . renderNestedBlocks)
<$> mapM (handleCSSUrls media sourceURL d) bs
handleCSSUrls :: MediaBag -> Maybe String -> FilePath -> NestedBlock
-> IO NestedBlock
handleCSSUrls media sourceURL d (NestedBlock t bs) =
NestedBlock t <$> mapM (handleCSSUrls media sourceURL d) bs
handleCSSUrls media sourceURL d (LeafBlock (selector, attrs)) = do
attrs' <- mapM (handleCSSAttr media sourceURL d) attrs
return (LeafBlock (selector, attrs'))
handleCSSAttr :: MediaBag -> Maybe String -> FilePath -> (Text, Text)
-> IO (Text, Text)
handleCSSAttr media sourceURL d (key, val) =
if "url(" `T.isPrefixOf` val
then do
let url = T.unpack $ dropParens $ T.drop 3 val
case url of
'#':_ -> return (key, val)
'd':'a':'t':'a':':':_ -> return (key, val)
_ -> do
let url' = if isURI url then url else d </> url
enc <- getDataURI media sourceURL "" url'
return (key, T.pack enc)
else return (key, val)
dropParens :: Text -> Text
dropParens = T.dropAround (`elem` ['(',')','"','\'',' ','\t','\n','\r'])
getDataURI :: MediaBag -> Maybe String -> MimeType -> String
-> IO String
getDataURI _ _ _ src@('d':'a':'t':'a':':':_) = return src
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
makeSelfContained :: WriterOptions -> String -> IO String
makeSelfContained opts inp = do
let tags = parseTags inp
out' <- mapM (convertTag (writerMediaBag opts) (writerSourceURL opts)) tags
return $ renderTags' out'