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Diffstat (limited to 'src/Text/Pandoc/Readers/MediaWiki.hs')
| -rw-r--r-- | src/Text/Pandoc/Readers/MediaWiki.hs | 594 |
1 files changed, 594 insertions, 0 deletions
diff --git a/src/Text/Pandoc/Readers/MediaWiki.hs b/src/Text/Pandoc/Readers/MediaWiki.hs new file mode 100644 index 000000000..7936be38b --- /dev/null +++ b/src/Text/Pandoc/Readers/MediaWiki.hs @@ -0,0 +1,594 @@ +{-# LANGUAGE RelaxedPolyRec #-} -- needed for inlinesBetween on GHC < 7 +{- + Copyright (C) 2012 John MacFarlane <jgm@berkeley.edu> + +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.Readers.MediaWiki + Copyright : Copyright (C) 2012 John MacFarlane + License : GNU GPL, version 2 or above + + Maintainer : John MacFarlane <jgm@berkeley.edu> + Stability : alpha + Portability : portable + +Conversion of mediawiki text to 'Pandoc' document. +-} +{- +TODO: +_ correctly handle tables within tables +_ parse templates? +-} +module Text.Pandoc.Readers.MediaWiki ( readMediaWiki ) where + +import Text.Pandoc.Definition +import qualified Text.Pandoc.Builder as B +import Text.Pandoc.Builder (Inlines, Blocks, trimInlines, (<>)) +import Text.Pandoc.Options +import Text.Pandoc.Readers.HTML ( htmlTag, isBlockTag, isCommentTag ) +import Text.Pandoc.XML ( fromEntities ) +import Text.Pandoc.Parsing hiding ( nested ) +import Text.Pandoc.Generic ( bottomUp ) +import Text.Pandoc.Shared ( stripTrailingNewlines, safeRead ) +import Data.Monoid (mconcat, mempty) +import Control.Applicative ((<$>), (<*), (*>), (<$)) +import Control.Monad +import Data.List (intersperse, intercalate, isPrefixOf ) +import Text.HTML.TagSoup +import Data.Sequence (viewl, ViewL(..), (<|)) +import Data.Char (isDigit) + +-- | Read mediawiki from an input string and return a Pandoc document. +readMediaWiki :: ReaderOptions -- ^ Reader options + -> String -- ^ String to parse (assuming @'\n'@ line endings) + -> Pandoc +readMediaWiki opts s = + case runParser parseMediaWiki MWState{ mwOptions = opts + , mwMaxNestingLevel = 4 + , mwNextLinkNumber = 1 + , mwCategoryLinks = [] + } + "source" (s ++ "\n") of + Left err' -> error $ "\nError:\n" ++ show err' + Right result -> result + +data MWState = MWState { mwOptions :: ReaderOptions + , mwMaxNestingLevel :: Int + , mwNextLinkNumber :: Int + , mwCategoryLinks :: [Inlines] + } + +type MWParser = Parser [Char] MWState + +-- +-- auxiliary functions +-- + +-- This is used to prevent exponential blowups for things like: +-- ''a'''a''a'''a''a'''a''a'''a +nested :: MWParser a -> MWParser a +nested p = do + nestlevel <- mwMaxNestingLevel `fmap` getState + guard $ nestlevel > 0 + updateState $ \st -> st{ mwMaxNestingLevel = mwMaxNestingLevel st - 1 } + res <- p + updateState $ \st -> st{ mwMaxNestingLevel = nestlevel } + return res + +specialChars :: [Char] +specialChars = "'[]<=&*{}|\"" + +spaceChars :: [Char] +spaceChars = " \n\t" + +sym :: String -> MWParser () +sym s = () <$ try (string s) + +newBlockTags :: [String] +newBlockTags = ["haskell","syntaxhighlight","source","gallery","references"] + +isBlockTag' :: Tag String -> Bool +isBlockTag' tag@(TagOpen t _) = (isBlockTag tag || t `elem` newBlockTags) && + t `notElem` eitherBlockOrInline +isBlockTag' tag@(TagClose t) = (isBlockTag tag || t `elem` newBlockTags) && + t `notElem` eitherBlockOrInline +isBlockTag' tag = isBlockTag tag + +isInlineTag' :: Tag String -> Bool +isInlineTag' (TagComment _) = True +isInlineTag' t = not (isBlockTag' t) + +eitherBlockOrInline :: [String] +eitherBlockOrInline = ["applet", "button", "del", "iframe", "ins", + "map", "area", "object"] + +htmlComment :: MWParser () +htmlComment = () <$ htmlTag isCommentTag + +inlinesInTags :: String -> MWParser Inlines +inlinesInTags tag = try $ do + (_,raw) <- htmlTag (~== TagOpen tag []) + if '/' `elem` raw -- self-closing tag + then return mempty + else trimInlines . mconcat <$> + manyTill inline (htmlTag (~== TagClose tag)) + +blocksInTags :: String -> MWParser Blocks +blocksInTags tag = try $ do + (_,raw) <- htmlTag (~== TagOpen tag []) + if '/' `elem` raw -- self-closing tag + then return mempty + else mconcat <$> manyTill block (htmlTag (~== TagClose tag)) + +charsInTags :: String -> MWParser [Char] +charsInTags tag = try $ do + (_,raw) <- htmlTag (~== TagOpen tag []) + if '/' `elem` raw -- self-closing tag + then return "" + else innerText . parseTags <$> + manyTill anyChar (htmlTag (~== TagClose tag)) + +-- +-- main parser +-- + +parseMediaWiki :: MWParser Pandoc +parseMediaWiki = do + bs <- mconcat <$> many block + spaces + eof + categoryLinks <- reverse . mwCategoryLinks <$> getState + let categories = if null categoryLinks + then mempty + else B.para $ mconcat $ intersperse B.space categoryLinks + return $ B.doc $ bs <> categories + +-- +-- block parsers +-- + +block :: MWParser Blocks +block = mempty <$ skipMany1 blankline + <|> table + <|> header + <|> hrule + <|> orderedList + <|> bulletList + <|> definitionList + <|> mempty <$ try (spaces *> htmlComment) + <|> preformatted + <|> blockTag + <|> (B.rawBlock "mediawiki" <$> template) + <|> para + +para :: MWParser Blocks +para = B.para . trimInlines . mconcat <$> many1 inline + +table :: MWParser Blocks +table = do + tableStart + styles <- manyTill anyChar newline + let tableWidth = case lookup "width" $ parseAttrs styles of + Just w -> maybe 1.0 id $ parseWidth w + Nothing -> 1.0 + caption <- option mempty tableCaption + optional rowsep + hasheader <- option False $ True <$ (lookAhead (char '!')) + (cellspecs',hdr) <- unzip <$> tableRow + let widths = map ((tableWidth *) . snd) cellspecs' + let restwidth = tableWidth - sum widths + let zerocols = length $ filter (==0.0) widths + let defaultwidth = if zerocols == 0 || zerocols == length widths + then 0.0 + else restwidth / fromIntegral zerocols + let widths' = map (\w -> if w == 0 then defaultwidth else w) widths + let cellspecs = zip (map fst cellspecs') widths' + rows' <- many $ try $ rowsep *> (map snd <$> tableRow) + tableEnd + let cols = length hdr + let (headers,rows) = if hasheader + then (hdr, rows') + else (replicate cols mempty, hdr:rows') + return $ B.table caption cellspecs headers rows + +parseAttrs :: String -> [(String,String)] +parseAttrs s = case parse (many parseAttr) "attributes" s of + Right r -> r + Left _ -> [] + +parseAttr :: Parser String () (String, String) +parseAttr = try $ do + skipMany spaceChar + k <- many1 letter + char '=' + char '"' + v <- many1Till anyChar (char '"') + return (k,v) + +tableStart :: MWParser () +tableStart = try $ guardColumnOne *> sym "{|" + +tableEnd :: MWParser () +tableEnd = try $ guardColumnOne *> sym "|}" <* blanklines + +rowsep :: MWParser () +rowsep = try $ guardColumnOne *> sym "|-" <* blanklines + +cellsep :: MWParser () +cellsep = try $ + (guardColumnOne <* + ( (char '|' <* notFollowedBy (oneOf "-}+")) + <|> (char '!') + ) + ) + <|> (() <$ try (string "||")) + <|> (() <$ try (string "!!")) + +tableCaption :: MWParser Inlines +tableCaption = try $ do + guardColumnOne + sym "|+" + skipMany spaceChar + res <- manyTill anyChar newline >>= parseFromString (many inline) + return $ trimInlines $ mconcat res + +tableRow :: MWParser [((Alignment, Double), Blocks)] +tableRow = try $ many tableCell + +tableCell :: MWParser ((Alignment, Double), Blocks) +tableCell = try $ do + cellsep + skipMany spaceChar + attrs <- option [] $ try $ parseAttrs <$> + manyTill (satisfy (/='\n')) (char '|' <* notFollowedBy (char '|')) + skipMany spaceChar + ls <- concat <$> many (notFollowedBy (cellsep <|> rowsep <|> tableEnd) *> + ((snd <$> withRaw table) <|> count 1 anyChar)) + bs <- parseFromString (mconcat <$> many block) ls + let align = case lookup "align" attrs of + Just "left" -> AlignLeft + Just "right" -> AlignRight + Just "center" -> AlignCenter + _ -> AlignDefault + let width = case lookup "width" attrs of + Just xs -> maybe 0.0 id $ parseWidth xs + Nothing -> 0.0 + return ((align, width), bs) + +parseWidth :: String -> Maybe Double +parseWidth s = + case reverse s of + ('%':ds) | all isDigit ds -> safeRead ('0':'.':reverse ds) + _ -> Nothing + +template :: MWParser String +template = try $ do + string "{{" + notFollowedBy (char '{') + let chunk = template <|> variable <|> many1 (noneOf "{}") <|> count 1 anyChar + contents <- manyTill chunk (try $ string "}}") + return $ "{{" ++ concat contents ++ "}}" + +blockTag :: MWParser Blocks +blockTag = do + (tag, _) <- lookAhead $ htmlTag isBlockTag' + case tag of + TagOpen "blockquote" _ -> B.blockQuote <$> blocksInTags "blockquote" + TagOpen "pre" _ -> B.codeBlock . trimCode <$> charsInTags "pre" + TagOpen "syntaxhighlight" attrs -> syntaxhighlight "syntaxhighlight" attrs + TagOpen "source" attrs -> syntaxhighlight "source" attrs + TagOpen "haskell" _ -> B.codeBlockWith ("",["haskell"],[]) . trimCode <$> + charsInTags "haskell" + TagOpen "gallery" _ -> blocksInTags "gallery" + TagOpen "p" _ -> mempty <$ htmlTag (~== tag) + TagClose "p" -> mempty <$ htmlTag (~== tag) + _ -> B.rawBlock "html" . snd <$> htmlTag (~== tag) + +trimCode :: String -> String +trimCode ('\n':xs) = stripTrailingNewlines xs +trimCode xs = stripTrailingNewlines xs + +syntaxhighlight :: String -> [Attribute String] -> MWParser Blocks +syntaxhighlight tag attrs = try $ do + let mblang = lookup "lang" attrs + let mbstart = lookup "start" attrs + let mbline = lookup "line" attrs + let classes = maybe [] (:[]) mblang ++ maybe [] (const ["numberLines"]) mbline + let kvs = maybe [] (\x -> [("startFrom",x)]) mbstart + contents <- charsInTags tag + return $ B.codeBlockWith ("",classes,kvs) $ trimCode contents + +hrule :: MWParser Blocks +hrule = B.horizontalRule <$ try (string "----" *> many (char '-') *> newline) + +guardColumnOne :: MWParser () +guardColumnOne = getPosition >>= \pos -> guard (sourceColumn pos == 1) + +preformatted :: MWParser Blocks +preformatted = try $ do + guardColumnOne + char ' ' + let endline' = B.linebreak <$ (try $ newline <* char ' ') + let whitespace' = B.str <$> many1 ('\160' <$ spaceChar) + let spToNbsp ' ' = '\160' + spToNbsp x = x + let nowiki' = mconcat . intersperse B.linebreak . map B.str . + lines . fromEntities . map spToNbsp <$> try + (htmlTag (~== TagOpen "nowiki" []) *> + manyTill anyChar (htmlTag (~== TagClose "nowiki"))) + let inline' = whitespace' <|> endline' <|> nowiki' <|> inline + let strToCode (Str s) = Code ("",[],[]) s + strToCode x = x + B.para . bottomUp strToCode . mconcat <$> many1 inline' + +header :: MWParser Blocks +header = try $ do + guardColumnOne + eqs <- many1 (char '=') + let lev = length eqs + guard $ lev <= 6 + contents <- trimInlines . mconcat <$> manyTill inline (count lev $ char '=') + return $ B.header lev contents + +bulletList :: MWParser Blocks +bulletList = B.bulletList <$> + ( many1 (listItem '*') + <|> (htmlTag (~== TagOpen "ul" []) *> spaces *> many (listItem '*' <|> li) <* + optional (htmlTag (~== TagClose "ul"))) ) + +orderedList :: MWParser Blocks +orderedList = + (B.orderedList <$> many1 (listItem '#')) + <|> (B.orderedList <$> (htmlTag (~== TagOpen "ul" []) *> spaces *> + many (listItem '#' <|> li) <* + optional (htmlTag (~== TagClose "ul")))) + <|> do (tag,_) <- htmlTag (~== TagOpen "ol" []) + spaces + items <- many (listItem '#' <|> li) + optional (htmlTag (~== TagClose "ol")) + let start = maybe 1 id $ safeRead $ fromAttrib "start" tag + return $ B.orderedListWith (start, DefaultStyle, DefaultDelim) items + +definitionList :: MWParser Blocks +definitionList = B.definitionList <$> many1 defListItem + +defListItem :: MWParser (Inlines, [Blocks]) +defListItem = try $ do + terms <- mconcat . intersperse B.linebreak <$> many defListTerm + -- we allow dd with no dt, or dt with no dd + defs <- if B.isNull terms + then many1 $ listItem ':' + else many $ listItem ':' + return (terms, defs) + +defListTerm :: MWParser Inlines +defListTerm = char ';' >> skipMany spaceChar >> manyTill anyChar newline >>= + parseFromString (trimInlines . mconcat <$> many inline) + +listStart :: Char -> MWParser () +listStart c = char c *> notFollowedBy listStartChar + +listStartChar :: MWParser Char +listStartChar = oneOf "*#;:" + +anyListStart :: MWParser Char +anyListStart = char '*' + <|> char '#' + <|> char ':' + <|> char ';' + +li :: MWParser Blocks +li = lookAhead (htmlTag (~== TagOpen "li" [])) *> + (firstParaToPlain <$> blocksInTags "li") <* spaces + +listItem :: Char -> MWParser Blocks +listItem c = try $ do + extras <- many (try $ char c <* lookAhead listStartChar) + if null extras + then listItem' c + else do + skipMany spaceChar + first <- concat <$> manyTill listChunk newline + rest <- many + (try $ string extras *> (concat <$> manyTill listChunk newline)) + contents <- parseFromString (many1 $ listItem' c) + (unlines (first : rest)) + case c of + '*' -> return $ B.bulletList contents + '#' -> return $ B.orderedList contents + ':' -> return $ B.definitionList [(mempty, contents)] + _ -> mzero + +-- The point of this is to handle stuff like +-- * {{cite book +-- | blah +-- | blah +-- }} +-- * next list item +-- which seems to be valid mediawiki. +listChunk :: MWParser String +listChunk = template <|> count 1 anyChar + +listItem' :: Char -> MWParser Blocks +listItem' c = try $ do + listStart c + skipMany spaceChar + first <- concat <$> manyTill listChunk newline + rest <- many (try $ char c *> lookAhead listStartChar *> + (concat <$> manyTill listChunk newline)) + parseFromString (firstParaToPlain . mconcat <$> many1 block) + $ unlines $ first : rest + +firstParaToPlain :: Blocks -> Blocks +firstParaToPlain contents = + case viewl (B.unMany contents) of + (Para xs) :< ys -> B.Many $ (Plain xs) <| ys + _ -> contents + +-- +-- inline parsers +-- + +inline :: MWParser Inlines +inline = whitespace + <|> url + <|> str + <|> doubleQuotes + <|> strong + <|> emph + <|> image + <|> internalLink + <|> externalLink + <|> inlineTag + <|> B.singleton <$> charRef + <|> inlineHtml + <|> (B.rawInline "mediawiki" <$> variable) + <|> (B.rawInline "mediawiki" <$> template) + <|> special + +str :: MWParser Inlines +str = B.str <$> many1 (noneOf $ specialChars ++ spaceChars) + +variable :: MWParser String +variable = try $ do + string "{{{" + contents <- manyTill anyChar (try $ string "}}}") + return $ "{{{" ++ contents ++ "}}}" + +inlineTag :: MWParser Inlines +inlineTag = do + (tag, _) <- lookAhead $ htmlTag isInlineTag' + case tag of + TagOpen "ref" _ -> B.note . B.plain <$> inlinesInTags "ref" + TagOpen "nowiki" _ -> try $ do + (_,raw) <- htmlTag (~== tag) + if '/' `elem` raw + then return mempty + else B.text . fromEntities <$> + manyTill anyChar (htmlTag (~== TagClose "nowiki")) + TagOpen "br" _ -> B.linebreak <$ (htmlTag (~== TagOpen "br" []) -- will get /> too + *> optional blankline) + TagOpen "strike" _ -> B.strikeout <$> inlinesInTags "strike" + TagOpen "del" _ -> B.strikeout <$> inlinesInTags "del" + TagOpen "sub" _ -> B.subscript <$> inlinesInTags "sub" + TagOpen "sup" _ -> B.superscript <$> inlinesInTags "sup" + TagOpen "math" _ -> B.math <$> charsInTags "math" + TagOpen "code" _ -> B.code <$> charsInTags "code" + TagOpen "tt" _ -> B.code <$> charsInTags "tt" + TagOpen "hask" _ -> B.codeWith ("",["haskell"],[]) <$> charsInTags "hask" + _ -> B.rawInline "html" . snd <$> htmlTag (~== tag) + +special :: MWParser Inlines +special = B.str <$> count 1 (notFollowedBy' (htmlTag isBlockTag') *> + oneOf specialChars) + +inlineHtml :: MWParser Inlines +inlineHtml = B.rawInline "html" . snd <$> htmlTag isInlineTag' + +whitespace :: MWParser Inlines +whitespace = B.space <$ (skipMany1 spaceChar <|> endline <|> htmlComment) + +endline :: MWParser () +endline = () <$ try (newline <* + notFollowedBy blankline <* + notFollowedBy' hrule <* + notFollowedBy tableStart <* + notFollowedBy' header <* + notFollowedBy anyListStart) + +image :: MWParser Inlines +image = try $ do + sym "[[" + sym "File:" + fname <- many1 (noneOf "|]") + _ <- many (try $ char '|' *> imageOption) + caption <- (B.str fname <$ sym "]]") + <|> try (char '|' *> (mconcat <$> manyTill inline (sym "]]"))) + return $ B.image fname "image" caption + +imageOption :: MWParser String +imageOption = + try (oneOfStrings [ "border", "thumbnail", "frameless" + , "thumb", "upright", "left", "right" + , "center", "none", "baseline", "sub" + , "super", "top", "text-top", "middle" + , "bottom", "text-bottom" ]) + <|> try (string "frame") + <|> try (many1 (oneOf "x0123456789") <* string "px") + <|> try (oneOfStrings ["link=","alt=","page=","class="] <* many (noneOf "|]")) + +internalLink :: MWParser Inlines +internalLink = try $ do + sym "[[" + let addUnderscores x = let (pref,suff) = break (=='#') x + in pref ++ intercalate "_" (words suff) + pagename <- unwords . words <$> many (noneOf "|]") + label <- option (B.text pagename) $ char '|' *> + ( (mconcat <$> many1 (notFollowedBy (char ']') *> inline)) + -- the "pipe trick" + -- [[Help:Contents|] -> "Contents" + <|> (return $ B.text $ drop 1 $ dropWhile (/=':') pagename) ) + sym "]]" + linktrail <- B.text <$> many letter + let link = B.link (addUnderscores pagename) "wikilink" (label <> linktrail) + if "Category:" `isPrefixOf` pagename + then do + updateState $ \st -> st{ mwCategoryLinks = link : mwCategoryLinks st } + return mempty + else return link + +externalLink :: MWParser Inlines +externalLink = try $ do + char '[' + (_, src) <- uri + lab <- try (trimInlines . mconcat <$> + (skipMany1 spaceChar *> manyTill inline (char ']'))) + <|> do char ']' + num <- mwNextLinkNumber <$> getState + updateState $ \st -> st{ mwNextLinkNumber = num + 1 } + return $ B.str $ show num + return $ B.link src "" lab + +url :: MWParser Inlines +url = do + (orig, src) <- uri + return $ B.link src "" (B.str orig) + +-- | Parses a list of inlines between start and end delimiters. +inlinesBetween :: (Show b) => MWParser a -> MWParser b -> MWParser Inlines +inlinesBetween start end = + (trimInlines . mconcat) <$> try (start >> many1Till inner end) + where inner = innerSpace <|> (notFollowedBy' (() <$ whitespace) >> inline) + innerSpace = try $ whitespace >>~ notFollowedBy' end + +emph :: MWParser Inlines +emph = B.emph <$> nested (inlinesBetween start end) + where start = sym "''" >> lookAhead nonspaceChar + end = try $ notFollowedBy' (() <$ strong) >> sym "''" + +strong :: MWParser Inlines +strong = B.strong <$> nested (inlinesBetween start end) + where start = sym "'''" >> lookAhead nonspaceChar + end = try $ sym "'''" + +doubleQuotes :: MWParser Inlines +doubleQuotes = B.doubleQuoted . trimInlines . mconcat <$> try + ((getState >>= guard . readerSmart . mwOptions) *> + openDoubleQuote *> manyTill inline closeDoubleQuote ) + where openDoubleQuote = char '"' <* lookAhead alphaNum + closeDoubleQuote = char '"' <* notFollowedBy alphaNum + |