{-# LANGUAGE NoImplicitPrelude #-} {-# LANGUAGE CPP #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE PatternGuards #-} {-# LANGUAGE ScopedTypeVariables #-} {- Copyright (C) 2010-2018 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.Writers.EPUB Copyright : Copyright (C) 2010-2018 John MacFarlane License : GNU GPL, version 2 or above Maintainer : John MacFarlane Stability : alpha Portability : portable Conversion of 'Pandoc' documents to EPUB. -} module Text.Pandoc.Writers.EPUB ( writeEPUB2, writeEPUB3 ) where import Prelude import Codec.Archive.Zip (Entry, addEntryToArchive, eRelativePath, emptyArchive, fromArchive, fromEntry, toEntry) import Control.Applicative ( (<|>) ) import Control.Monad (mplus, unless, when, zipWithM) import Control.Monad.Except (catchError, throwError) import Control.Monad.State.Strict (State, StateT, evalState, evalStateT, get, gets, lift, modify, put) import qualified Data.ByteString.Lazy as B import qualified Data.ByteString.Lazy.Char8 as B8 import Data.Char (isAlphaNum, isAscii, isDigit, toLower) import Data.List (intercalate, isInfixOf, isPrefixOf) import qualified Data.Map as M import Data.Maybe (fromMaybe, isNothing, mapMaybe, isJust) import qualified Data.Set as Set import qualified Data.Text as TS import qualified Data.Text.Lazy as TL import Network.HTTP (urlEncode) import System.FilePath (takeExtension, takeFileName, makeRelative) import Text.HTML.TagSoup (Tag (TagOpen), fromAttrib, parseTags) import Text.Pandoc.Builder (fromList, setMeta) import Text.Pandoc.Class (PandocMonad, report) import qualified Text.Pandoc.Class as P import Data.Time import Text.Pandoc.Definition import Text.Pandoc.Error import Text.Pandoc.Logging import Text.Pandoc.MIME (MimeType, extensionFromMimeType, getMimeType) import Text.Pandoc.Options (EPUBVersion (..), HTMLMathMethod (..), ObfuscationMethod (NoObfuscation), WrapOption (..), WriterOptions (..)) import Text.Pandoc.Shared (hierarchicalize, normalizeDate, renderTags', safeRead, stringify, trim, uniqueIdent) import qualified Text.Pandoc.Shared as S (Element (..)) import qualified Text.Pandoc.UTF8 as UTF8 import Text.Pandoc.UUID (getUUID) import Text.Pandoc.Walk (query, walk, walkM) import Text.Pandoc.Writers.HTML (writeHtmlStringForEPUB) import Text.Printf (printf) import Text.XML.Light (Attr (..), Element (..), Node (..), QName (..), add_attrs, lookupAttr, node, onlyElems, parseXML, ppElement, showElement, strContent, unode, unqual) import Text.Pandoc.XML (escapeStringForXML) -- A Chapter includes a list of blocks and maybe a section -- number offset. Note, some chapters are unnumbered. The section -- number is different from the index number, which will be used -- in filenames, chapter0003.xhtml. data Chapter = Chapter (Maybe [Int]) [Block] data EPUBState = EPUBState { stMediaPaths :: [(FilePath, (FilePath, Maybe Entry))] , stEpubSubdir :: String } type E m = StateT EPUBState m data EPUBMetadata = EPUBMetadata{ epubIdentifier :: [Identifier] , epubTitle :: [Title] , epubDate :: [Date] , epubLanguage :: String , epubCreator :: [Creator] , epubContributor :: [Creator] , epubSubject :: [String] , epubDescription :: Maybe String , epubType :: Maybe String , epubFormat :: Maybe String , epubPublisher :: Maybe String , epubSource :: Maybe String , epubRelation :: Maybe String , epubCoverage :: Maybe String , epubRights :: Maybe String , epubCoverImage :: Maybe String , epubStylesheets :: [FilePath] , epubPageDirection :: Maybe ProgressionDirection , epubIbooksFields :: [(String, String)] , epubCalibreFields :: [(String, String)] } deriving Show data Date = Date{ dateText :: String , dateEvent :: Maybe String } deriving Show data Creator = Creator{ creatorText :: String , creatorRole :: Maybe String , creatorFileAs :: Maybe String } deriving Show data Identifier = Identifier{ identifierText :: String , identifierScheme :: Maybe String } deriving Show data Title = Title{ titleText :: String , titleFileAs :: Maybe String , titleType :: Maybe String } deriving Show data ProgressionDirection = LTR | RTL deriving Show dcName :: String -> QName dcName n = QName n Nothing (Just "dc") dcNode :: Node t => String -> t -> Element dcNode = node . dcName opfName :: String -> QName opfName n = QName n Nothing (Just "opf") toId :: FilePath -> String toId = map (\x -> if isAlphaNum x || x == '-' || x == '_' then x else '_') . takeFileName removeNote :: Inline -> Inline removeNote (Note _) = Str "" removeNote x = x mkEntry :: PandocMonad m => FilePath -> B.ByteString -> E m Entry mkEntry path content = do epubSubdir <- gets stEpubSubdir let addEpubSubdir :: Entry -> Entry addEpubSubdir e = e{ eRelativePath = (if null epubSubdir then "" else epubSubdir ++ "/") ++ eRelativePath e } epochtime <- floor <$> lift P.getPOSIXTime return $ (if path == "mimetype" || "META-INF" `isPrefixOf` path then id else addEpubSubdir) $ toEntry path epochtime content getEPUBMetadata :: PandocMonad m => WriterOptions -> Meta -> E m EPUBMetadata getEPUBMetadata opts meta = do let md = metadataFromMeta opts meta let elts = maybe [] (onlyElems . parseXML) $ writerEpubMetadata opts let md' = foldr addMetadataFromXML md elts let addIdentifier m = if null (epubIdentifier m) then do randomId <- (show . getUUID) <$> lift P.newStdGen return $ m{ epubIdentifier = [Identifier randomId Nothing] } else return m let addLanguage m = if null (epubLanguage m) then case lookup "lang" (writerVariables opts) of Just x -> return m{ epubLanguage = x } Nothing -> do mLang <- lift $ P.lookupEnv "LANG" let localeLang = case mLang of Just lang -> map (\c -> if c == '_' then '-' else c) $ takeWhile (/='.') lang Nothing -> "en-US" return m{ epubLanguage = localeLang } else return m let fixDate m = if null (epubDate m) then do currentTime <- lift P.getCurrentTime return $ m{ epubDate = [ Date{ dateText = showDateTimeISO8601 currentTime , dateEvent = Nothing } ] } else return m let addAuthor m = if any (\c -> creatorRole c == Just "aut") $ epubCreator m then return m else do let authors' = map stringify $ docAuthors meta let toAuthor name = Creator{ creatorText = name , creatorRole = Just "aut" , creatorFileAs = Nothing } return $ m{ epubCreator = map toAuthor authors' ++ epubCreator m } addIdentifier md' >>= fixDate >>= addAuthor >>= addLanguage addMetadataFromXML :: Element -> EPUBMetadata -> EPUBMetadata addMetadataFromXML e@(Element (QName name _ (Just "dc")) attrs _ _) md | name == "identifier" = md{ epubIdentifier = Identifier{ identifierText = strContent e , identifierScheme = lookupAttr (opfName "scheme") attrs } : epubIdentifier md } | name == "title" = md{ epubTitle = Title{ titleText = strContent e , titleFileAs = getAttr "file-as" , titleType = getAttr "type" } : epubTitle md } | name == "date" = md{ epubDate = Date{ dateText = fromMaybe "" $ normalizeDate' $ strContent e , dateEvent = getAttr "event" } : epubDate md } | name == "language" = md{ epubLanguage = strContent e } | name == "creator" = md{ epubCreator = Creator{ creatorText = strContent e , creatorRole = getAttr "role" , creatorFileAs = getAttr "file-as" } : epubCreator md } | name == "contributor" = md{ epubContributor = Creator { creatorText = strContent e , creatorRole = getAttr "role" , creatorFileAs = getAttr "file-as" } : epubContributor md } | name == "subject" = md{ epubSubject = strContent e : epubSubject md } | name == "description" = md { epubDescription = Just $ strContent e } | name == "type" = md { epubType = Just $ strContent e } | name == "format" = md { epubFormat = Just $ strContent e } | name == "type" = md { epubType = Just $ strContent e } | name == "publisher" = md { epubPublisher = Just $ strContent e } | name == "source" = md { epubSource = Just $ strContent e } | name == "relation" = md { epubRelation = Just $ strContent e } | name == "coverage" = md { epubCoverage = Just $ strContent e } | name == "rights" = md { epubRights = Just $ strContent e } | otherwise = md where getAttr n = lookupAttr (opfName n) attrs addMetadataFromXML e@(Element (QName "meta" _ _) attrs _ _) md = case getAttr "property" of Just s | "ibooks:" `isPrefixOf` s -> md{ epubIbooksFields = (drop 7 s, strContent e) : epubIbooksFields md } _ -> case getAttr "name" of Just s | "calibre:" `isPrefixOf` s -> md{ epubCalibreFields = (drop 8 s, fromMaybe "" $ getAttr "content") : epubCalibreFields md } _ -> md where getAttr n = lookupAttr (unqual n) attrs addMetadataFromXML _ md = md metaValueToString :: MetaValue -> String metaValueToString (MetaString s) = s metaValueToString (MetaInlines ils) = stringify ils metaValueToString (MetaBlocks bs) = stringify bs metaValueToString (MetaBool True) = "true" metaValueToString (MetaBool False) = "false" metaValueToString _ = "" metaValueToPaths:: MetaValue -> [FilePath] metaValueToPaths (MetaList xs) = map metaValueToString xs metaValueToPaths x = [metaValueToString x] getList :: String -> Meta -> (MetaValue -> a) -> [a] getList s meta handleMetaValue = case lookupMeta s meta of Just (MetaList xs) -> map handleMetaValue xs Just mv -> [handleMetaValue mv] Nothing -> [] getIdentifier :: Meta -> [Identifier] getIdentifier meta = getList "identifier" meta handleMetaValue where handleMetaValue (MetaMap m) = Identifier{ identifierText = maybe "" metaValueToString $ M.lookup "text" m , identifierScheme = metaValueToString <$> M.lookup "scheme" m } handleMetaValue mv = Identifier (metaValueToString mv) Nothing getTitle :: Meta -> [Title] getTitle meta = getList "title" meta handleMetaValue where handleMetaValue (MetaMap m) = Title{ titleText = maybe "" metaValueToString $ M.lookup "text" m , titleFileAs = metaValueToString <$> M.lookup "file-as" m , titleType = metaValueToString <$> M.lookup "type" m } handleMetaValue mv = Title (metaValueToString mv) Nothing Nothing getCreator :: String -> Meta -> [Creator] getCreator s meta = getList s meta handleMetaValue where handleMetaValue (MetaMap m) = Creator{ creatorText = maybe "" metaValueToString $ M.lookup "text" m , creatorFileAs = metaValueToString <$> M.lookup "file-as" m , creatorRole = metaValueToString <$> M.lookup "role" m } handleMetaValue mv = Creator (metaValueToString mv) Nothing Nothing getDate :: String -> Meta -> [Date] getDate s meta = getList s meta handleMetaValue where handleMetaValue (MetaMap m) = Date{ dateText = fromMaybe "" $ M.lookup "text" m >>= normalizeDate' . metaValueToString , dateEvent = metaValueToString <$> M.lookup "event" m } handleMetaValue mv = Date { dateText = fromMaybe "" $ normalizeDate' $ metaValueToString mv , dateEvent = Nothing } simpleList :: String -> Meta -> [String] simpleList s meta = case lookupMeta s meta of Just (MetaList xs) -> map metaValueToString xs Just x -> [metaValueToString x] Nothing -> [] metadataFromMeta :: WriterOptions -> Meta -> EPUBMetadata metadataFromMeta opts meta = EPUBMetadata{ epubIdentifier = identifiers , epubTitle = titles , epubDate = date , epubLanguage = language , epubCreator = creators , epubContributor = contributors , epubSubject = subjects , epubDescription = description , epubType = epubtype , epubFormat = format , epubPublisher = publisher , epubSource = source , epubRelation = relation , epubCoverage = coverage , epubRights = rights , epubCoverImage = coverImage , epubStylesheets = stylesheets , epubPageDirection = pageDirection , epubIbooksFields = ibooksFields , epubCalibreFields = calibreFields } where identifiers = getIdentifier meta titles = getTitle meta date = getDate "date" meta language = maybe "" metaValueToString $ lookupMeta "language" meta `mplus` lookupMeta "lang" meta creators = getCreator "creator" meta contributors = getCreator "contributor" meta subjects = simpleList "subject" meta description = metaValueToString <$> lookupMeta "description" meta epubtype = metaValueToString <$> lookupMeta "type" meta format = metaValueToString <$> lookupMeta "format" meta publisher = metaValueToString <$> lookupMeta "publisher" meta source = metaValueToString <$> lookupMeta "source" meta relation = metaValueToString <$> lookupMeta "relation" meta coverage = metaValueToString <$> lookupMeta "coverage" meta rights = metaValueToString <$> lookupMeta "rights" meta coverImage = lookup "epub-cover-image" (writerVariables opts) `mplus` (metaValueToString <$> lookupMeta "cover-image" meta) mCss = lookupMeta "css" meta <|> lookupMeta "stylesheet" meta stylesheets = fromMaybe [] (metaValueToPaths <$> mCss) ++ [f | ("css",f) <- writerVariables opts] pageDirection = case map toLower . metaValueToString <$> lookupMeta "page-progression-direction" meta of Just "ltr" -> Just LTR Just "rtl" -> Just RTL _ -> Nothing ibooksFields = case lookupMeta "ibooks" meta of Just (MetaMap mp) -> M.toList $ M.map metaValueToString mp _ -> [] calibreFields = case lookupMeta "calibre" meta of Just (MetaMap mp) -> M.toList $ M.map metaValueToString mp _ -> [] -- | Produce an EPUB2 file from a Pandoc document. writeEPUB2 :: PandocMonad m => WriterOptions -- ^ Writer options -> Pandoc -- ^ Document to convert -> m B.ByteString writeEPUB2 = writeEPUB EPUB2 -- | Produce an EPUB3 file from a Pandoc document. writeEPUB3 :: PandocMonad m => WriterOptions -- ^ Writer options -> Pandoc -- ^ Document to convert -> m B.ByteString writeEPUB3 = writeEPUB EPUB3 -- | Produce an EPUB file from a Pandoc document. writeEPUB :: PandocMonad m => EPUBVersion -> WriterOptions -- ^ Writer options -> Pandoc -- ^ Document to convert -> m B.ByteString writeEPUB epubVersion opts doc = do let epubSubdir = writerEpubSubdirectory opts -- sanity check on epubSubdir unless (all (\c -> isAscii c && isAlphaNum c) epubSubdir) $ throwError $ PandocEpubSubdirectoryError epubSubdir let initState = EPUBState { stMediaPaths = [], stEpubSubdir = epubSubdir } evalStateT (pandocToEPUB epubVersion opts doc) initState pandocToEPUB :: PandocMonad m => EPUBVersion -> WriterOptions -> Pandoc -> E m B.ByteString pandocToEPUB version opts doc@(Pandoc meta _) = do epubSubdir <- gets stEpubSubdir let epub3 = version == EPUB3 let writeHtml o = fmap (UTF8.fromTextLazy . TL.fromStrict) . writeHtmlStringForEPUB version o metadata <- getEPUBMetadata opts meta let plainTitle = case docTitle' meta of [] -> case epubTitle metadata of [] -> "UNTITLED" (x:_) -> titleText x x -> stringify x -- stylesheet stylesheets <- case epubStylesheets metadata of [] -> (\x -> [B.fromChunks [x]]) <$> P.readDataFile "epub.css" fs -> mapM P.readFileLazy fs stylesheetEntries <- zipWithM (\bs n -> mkEntry ("styles/stylesheet" ++ show n ++ ".css") bs) stylesheets [(1 :: Int)..] let vars = ("epub3", if epub3 then "true" else "false") : [(x,y) | (x,y) <- writerVariables opts, x /= "css"] let cssvars useprefix = map (\e -> ("css", (if useprefix then "../" else "") ++ makeRelative epubSubdir (eRelativePath e))) stylesheetEntries let opts' = opts{ writerEmailObfuscation = NoObfuscation , writerSectionDivs = True , writerVariables = vars , writerHTMLMathMethod = if epub3 then MathML else writerHTMLMathMethod opts , writerWrapText = WrapAuto } -- cover page (cpgEntry, cpicEntry) <- case epubCoverImage metadata of Nothing -> return ([],[]) Just img -> do let coverImage = takeFileName img cpContent <- lift $ writeHtml opts'{ writerVariables = ("coverpage","true"): ("pagetitle", escapeStringForXML plainTitle): cssvars True ++ vars } (Pandoc meta [RawBlock (Format "html") $ "
\n\"cover\n
"]) imgContent <- lift $ P.readFileLazy img coverEntry <- mkEntry "text/cover.xhtml" cpContent coverImageEntry <- mkEntry ("media/" ++ coverImage) imgContent return ( [ coverEntry ] , [ coverImageEntry ] ) -- title page tpContent <- lift $ writeHtml opts'{ writerVariables = ("titlepage","true"): ("body-type", "frontmatter"): ("pagetitle", escapeStringForXML plainTitle): cssvars True ++ vars } (Pandoc meta []) tpEntry <- mkEntry "text/title_page.xhtml" tpContent -- handle pictures -- mediaRef <- P.newIORef [] Pandoc _ blocks <- walkM (transformInline opts') doc >>= walkM transformBlock picEntries <- mapMaybe (snd . snd) <$> gets stMediaPaths -- handle fonts let matchingGlob f = do xs <- lift $ P.glob f when (null xs) $ report $ CouldNotFetchResource f "glob did not match any font files" return xs let mkFontEntry f = mkEntry ("fonts/" ++ takeFileName f) =<< lift (P.readFileLazy f) fontFiles <- concat <$> mapM matchingGlob (writerEpubFonts opts') fontEntries <- mapM mkFontEntry fontFiles -- set page progression direction attribution let progressionDirection = case epubPageDirection metadata of Just LTR | epub3 -> [("page-progression-direction", "ltr")] Just RTL | epub3 -> [("page-progression-direction", "rtl")] _ -> [] -- body pages -- add level 1 header to beginning if none there let blocks' = addIdentifiers opts $ case blocks of (Header 1 _ _ : _) -> blocks _ -> Header 1 ("",["unnumbered"],[]) (docTitle' meta) : blocks let chapterHeaderLevel = writerEpubChapterLevel opts let isChapterHeader (Header n _ _) = n <= chapterHeaderLevel isChapterHeader (Div ("refs",_,_) (Header n _ _:_)) = n <= chapterHeaderLevel isChapterHeader _ = False let toChapters :: [Block] -> State [Int] [Chapter] toChapters [] = return [] toChapters (Div ("refs",_,_) bs@(Header 1 _ _:_) : rest) = toChapters (bs ++ rest) toChapters (Header n attr@(_,classes,_) ils : bs) = do nums <- get mbnum <- if "unnumbered" `elem` classes then return Nothing else case splitAt (n - 1) nums of (ks, m:_) -> do let nums' = ks ++ [m+1] put nums' return $ Just (ks ++ [m]) -- note, this is the offset not the sec number (ks, []) -> do let nums' = ks ++ [1] put nums' return $ Just ks let (xs,ys) = break isChapterHeader bs (Chapter mbnum (Header n attr ils : xs) :) `fmap` toChapters ys toChapters (b:bs) = do let (xs,ys) = break isChapterHeader bs (Chapter Nothing (b:xs) :) `fmap` toChapters ys let chapters' = evalState (toChapters blocks') [] let extractLinkURL' :: Int -> Inline -> [(String, String)] extractLinkURL' num (Span (ident, _, _) _) | not (null ident) = [(ident, showChapter num ++ ('#':ident))] extractLinkURL' _ _ = [] let extractLinkURL :: Int -> Block -> [(String, String)] extractLinkURL num (Div (ident, _, _) _) | not (null ident) = [(ident, showChapter num ++ ('#':ident))] extractLinkURL num (Header _ (ident, _, _) _) | not (null ident) = [(ident, showChapter num ++ ('#':ident))] extractLinkURL num b = query (extractLinkURL' num) b let reftable = concat $ zipWith (\(Chapter _ bs) num -> query (extractLinkURL num) bs) chapters' [1..] let fixInternalReferences :: Inline -> Inline fixInternalReferences (Link attr lab ('#':xs, tit)) = case lookup xs reftable of Just ys -> Link attr lab (ys, tit) Nothing -> Link attr lab ('#':xs, tit) fixInternalReferences x = x -- internal reference IDs change when we chunk the file, -- so that '#my-header-1' might turn into 'chap004.xhtml#my-header'. -- this fixes that: let chapters = map (\(Chapter mbnum bs) -> Chapter mbnum $ walk fixInternalReferences bs) chapters' let chapToEntry num (Chapter mbnum bs) = mkEntry ("text/" ++ showChapter num) =<< writeHtml opts'{ writerNumberOffset = fromMaybe [] mbnum , writerVariables = ("body-type", bodyType) : cssvars True ++ vars } pdoc where (pdoc, bodyType) = case bs of (Header _ (_,_,kvs) xs : _) -> -- remove notes or we get doubled footnotes (Pandoc (setMeta "title" (walk removeNote $ fromList xs) nullMeta) bs, case lookup "epub:type" kvs of Nothing -> "bodymatter" Just x | x `elem` frontMatterTypes -> "frontmatter" | x `elem` backMatterTypes -> "backmatter" | otherwise -> "bodymatter") _ -> (Pandoc nullMeta bs, "bodymatter") frontMatterTypes = ["prologue", "abstract", "acknowledgments", "copyright-page", "dedication", "foreword", "halftitle", "introduction", "preface", "seriespage", "titlepage"] backMatterTypes = ["afterword", "appendix", "colophon", "conclusion", "epigraph"] chapterEntries <- zipWithM chapToEntry [1..] chapters -- incredibly inefficient (TODO): let containsMathML ent = epub3 && " [] xs -> [("properties", unwords xs)]) $ () let chapterRefNode ent = unode "itemref" ! [("idref", toId $ makeRelative epubSubdir $ eRelativePath ent)] $ () let pictureNode ent = unode "item" ! [("id", toId $ makeRelative epubSubdir $ eRelativePath ent), ("href", makeRelative epubSubdir $ eRelativePath ent), ("media-type", fromMaybe "application/octet-stream" $ mediaTypeOf $ eRelativePath ent)] $ () let fontNode ent = unode "item" ! [("id", toId $ makeRelative epubSubdir $ eRelativePath ent), ("href", makeRelative epubSubdir $ eRelativePath ent), ("media-type", fromMaybe "" $ getMimeType $ eRelativePath ent)] $ () let tocTitle = fromMaybe plainTitle $ metaValueToString <$> lookupMeta "toc-title" meta uuid <- case epubIdentifier metadata of (x:_) -> return $ identifierText x -- use first identifier as UUID [] -> throwError $ PandocShouldNeverHappenError "epubIdentifier is null" -- shouldn't happen currentTime <- lift P.getCurrentTime let contentsData = UTF8.fromStringLazy $ ppTopElement $ unode "package" ! ([("version", case version of EPUB2 -> "2.0" EPUB3 -> "3.0") ,("xmlns","http://www.idpf.org/2007/opf") ,("unique-identifier","epub-id-1") ] ++ [("prefix","ibooks: http://vocabulary.itunes.apple.com/rdf/ibooks/vocabulary-extensions-1.0/") | version == EPUB3]) $ [ metadataElement version metadata currentTime , unode "manifest" $ [ unode "item" ! [("id","ncx"), ("href","toc.ncx") ,("media-type","application/x-dtbncx+xml")] $ () , unode "item" ! ([("id","nav") ,("href","nav.xhtml") ,("media-type","application/xhtml+xml")] ++ [("properties","nav") | epub3 ]) $ () ] ++ [ unode "item" ! [("id","style"), ("href",fp) ,("media-type","text/css")] $ () | fp <- map (makeRelative epubSubdir . eRelativePath) stylesheetEntries ] ++ map chapterNode (cpgEntry ++ (tpEntry : chapterEntries)) ++ (case cpicEntry of [] -> [] (x:_) -> [add_attrs [Attr (unqual "properties") "cover-image" | epub3] (pictureNode x)]) ++ map pictureNode picEntries ++ map fontNode fontEntries , unode "spine" ! ( ("toc","ncx") : progressionDirection) $ case epubCoverImage metadata of Nothing -> [] Just _ -> [ unode "itemref" ! [("idref", "cover_xhtml")] $ () ] ++ ((unode "itemref" ! [("idref", "title_page_xhtml") ,("linear", case lookupMeta "title" meta of Just _ -> "yes" Nothing -> "no")] $ ()) : [unode "itemref" ! [("idref", "nav")] $ () | writerTableOfContents opts ] ++ map chapterRefNode chapterEntries) , unode "guide" $ [ unode "reference" ! [("type","toc"),("title", tocTitle), ("href","nav.xhtml")] $ () ] ++ [ unode "reference" ! [("type","cover") ,("title","Cover") ,("href","text/cover.xhtml")] $ () | isJust (epubCoverImage metadata) ] ] contentsEntry <- mkEntry "content.opf" contentsData -- toc.ncx let secs = hierarchicalize blocks' let tocLevel = writerTOCDepth opts let navPointNode :: PandocMonad m => (Int -> [Inline] -> String -> [Element] -> Element) -> S.Element -> StateT Int m Element navPointNode formatter (S.Sec _ nums (ident,_,_) ils children) = do n <- get modify (+1) let showNums :: [Int] -> String showNums = intercalate "." . map show let tit = if writerNumberSections opts && not (null nums) then Span ("", ["section-header-number"], []) [Str (showNums nums)] : Space : ils else ils src <- case lookup ident reftable of Just x -> return x Nothing -> throwError $ PandocSomeError $ ident ++ " not found in reftable" let isSec (S.Sec lev _ _ _ _) = lev <= tocLevel isSec _ = False let subsecs = filter isSec children subs <- mapM (navPointNode formatter) subsecs return $ formatter n tit src subs navPointNode _ (S.Blk _) = throwError $ PandocSomeError "navPointNode encountered Blk" let navMapFormatter :: Int -> [Inline] -> String -> [Element] -> Element navMapFormatter n tit src subs = unode "navPoint" ! [("id", "navPoint-" ++ show n)] $ [ unode "navLabel" $ unode "text" $ stringify tit , unode "content" ! [("src", "text/" ++ src)] $ () ] ++ subs let tpNode = unode "navPoint" ! [("id", "navPoint-0")] $ [ unode "navLabel" $ unode "text" (stringify $ docTitle' meta) , unode "content" ! [("src", "text/title_page.xhtml")] $ () ] navMap <- lift $ evalStateT (mapM (navPointNode navMapFormatter) secs) 1 let tocData = UTF8.fromStringLazy $ ppTopElement $ unode "ncx" ! [("version","2005-1") ,("xmlns","http://www.daisy.org/z3986/2005/ncx/")] $ [ unode "head" $ [ unode "meta" ! [("name","dtb:uid") ,("content", uuid)] $ () , unode "meta" ! [("name","dtb:depth") ,("content", "1")] $ () , unode "meta" ! [("name","dtb:totalPageCount") ,("content", "0")] $ () , unode "meta" ! [("name","dtb:maxPageNumber") ,("content", "0")] $ () ] ++ case epubCoverImage metadata of Nothing -> [] Just img -> [unode "meta" ! [("name","cover"), ("content", toId img)] $ ()] , unode "docTitle" $ unode "text" plainTitle , unode "navMap" $ tpNode : navMap ] tocEntry <- mkEntry "toc.ncx" tocData let navXhtmlFormatter :: Int -> [Inline] -> String -> [Element] -> Element navXhtmlFormatter n tit src subs = unode "li" ! [("id", "toc-li-" ++ show n)] $ (unode "a" ! [("href", "text/" ++ src)] $ titElements) : case subs of [] -> [] (_:_) -> [unode "ol" ! [("class","toc")] $ subs] where titElements = parseXML titRendered titRendered = case P.runPure (writeHtmlStringForEPUB version opts{ writerTemplate = Nothing , writerVariables = ("pagetitle", escapeStringForXML plainTitle): writerVariables opts} (Pandoc nullMeta [Plain $ walk clean tit])) of Left _ -> TS.pack $ stringify tit Right x -> x -- can't have elements inside generated links... clean (Link _ ils _) = Span ("", [], []) ils clean (Note _) = Str "" clean x = x let navtag = if epub3 then "nav" else "div" tocBlocks <- lift $ evalStateT (mapM (navPointNode navXhtmlFormatter) secs) 1 let navBlocks = [RawBlock (Format "html") $ showElement $ -- prettyprinting introduces bad spaces unode navtag ! ([("epub:type","toc") | epub3] ++ [("id","toc")]) $ [ unode "h1" ! [("id","toc-title")] $ tocTitle , unode "ol" ! [("class","toc")] $ tocBlocks ]] let landmarks = if epub3 then [RawBlock (Format "html") $ ppElement $ unode "nav" ! [("epub:type","landmarks") ,("id","landmarks") ,("hidden","hidden")] $ [ unode "ol" $ [ unode "li" [ unode "a" ! [("href", "text/cover.xhtml") ,("epub:type", "cover")] $ "Cover"] | isJust (epubCoverImage metadata) ] ++ [ unode "li" [ unode "a" ! [("href", "#toc") ,("epub:type", "toc")] $ "Table of contents" ] | writerTableOfContents opts ] ] ] else [] navData <- lift $ writeHtml opts'{ writerVariables = ("navpage","true"): cssvars False ++ vars } (Pandoc (setMeta "title" (walk removeNote $ fromList $ docTitle' meta) nullMeta) (navBlocks ++ landmarks)) navEntry <- mkEntry "nav.xhtml" navData -- mimetype mimetypeEntry <- mkEntry "mimetype" $ UTF8.fromStringLazy "application/epub+zip" -- container.xml let containerData = UTF8.fromStringLazy $ ppTopElement $ unode "container" ! [("version","1.0") ,("xmlns","urn:oasis:names:tc:opendocument:xmlns:container")] $ unode "rootfiles" $ unode "rootfile" ! [("full-path", (if null epubSubdir then "" else epubSubdir ++ "/") ++ "content.opf") ,("media-type","application/oebps-package+xml")] $ () containerEntry <- mkEntry "META-INF/container.xml" containerData -- com.apple.ibooks.display-options.xml let apple = UTF8.fromStringLazy $ ppTopElement $ unode "display_options" $ unode "platform" ! [("name","*")] $ unode "option" ! [("name","specified-fonts")] $ "true" appleEntry <- mkEntry "META-INF/com.apple.ibooks.display-options.xml" apple -- construct archive let archive = foldr addEntryToArchive emptyArchive $ [mimetypeEntry, containerEntry, appleEntry, contentsEntry, tocEntry, navEntry, tpEntry] ++ stylesheetEntries ++ picEntries ++ cpicEntry ++ cpgEntry ++ chapterEntries ++ fontEntries return $ fromArchive archive metadataElement :: EPUBVersion -> EPUBMetadata -> UTCTime -> Element metadataElement version md currentTime = unode "metadata" ! [("xmlns:dc","http://purl.org/dc/elements/1.1/") ,("xmlns:opf","http://www.idpf.org/2007/opf")] $ mdNodes where mdNodes = identifierNodes ++ titleNodes ++ dateNodes ++ languageNodes ++ ibooksNodes ++ calibreNodes ++ creatorNodes ++ contributorNodes ++ subjectNodes ++ descriptionNodes ++ typeNodes ++ formatNodes ++ publisherNodes ++ sourceNodes ++ relationNodes ++ coverageNodes ++ rightsNodes ++ coverImageNodes ++ modifiedNodes withIds base f = concat . zipWith f (map (\x -> base ++ ('-' : show x)) ([1..] :: [Int])) identifierNodes = withIds "epub-id" toIdentifierNode $ epubIdentifier md titleNodes = withIds "epub-title" toTitleNode $ epubTitle md dateNodes = if version == EPUB2 then withIds "epub-date" toDateNode $ epubDate md else -- epub3 allows only one dc:date -- http://www.idpf.org/epub/30/spec/epub30-publications.html#sec-opf-dcdate case epubDate md of [] -> [] (x:_) -> [dcNode "date" ! [("id","epub-date")] $ dateText x] ibooksNodes = map ibooksNode (epubIbooksFields md) ibooksNode (k, v) = unode "meta" ! [("property", "ibooks:" ++ k)] $ v calibreNodes = map calibreNode (epubCalibreFields md) calibreNode (k, v) = unode "meta" ! [("name", "calibre:" ++ k), ("content", v)] $ () languageNodes = [dcTag "language" $ epubLanguage md] creatorNodes = withIds "epub-creator" (toCreatorNode "creator") $ epubCreator md contributorNodes = withIds "epub-contributor" (toCreatorNode "contributor") $ epubContributor md subjectNodes = map (dcTag "subject") $ epubSubject md descriptionNodes = maybe [] (dcTag' "description") $ epubDescription md typeNodes = maybe [] (dcTag' "type") $ epubType md formatNodes = maybe [] (dcTag' "format") $ epubFormat md publisherNodes = maybe [] (dcTag' "publisher") $ epubPublisher md sourceNodes = maybe [] (dcTag' "source") $ epubSource md relationNodes = maybe [] (dcTag' "relation") $ epubRelation md coverageNodes = maybe [] (dcTag' "coverage") $ epubCoverage md rightsNodes = maybe [] (dcTag' "rights") $ epubRights md coverImageNodes = maybe [] (\img -> [unode "meta" ! [("name","cover"), ("content",toId img)] $ ()]) $ epubCoverImage md modifiedNodes = [ unode "meta" ! [("property", "dcterms:modified")] $ showDateTimeISO8601 currentTime | version == EPUB3 ] dcTag n s = unode ("dc:" ++ n) s dcTag' n s = [dcTag n s] toIdentifierNode id' (Identifier txt scheme) | version == EPUB2 = [dcNode "identifier" ! (("id",id') : maybe [] (\x -> [("opf:scheme", x)]) scheme) $ txt] | otherwise = [dcNode "identifier" ! [("id",id')] $ txt] ++ maybe [] (\x -> [unode "meta" ! [("refines",'#':id'),("property","identifier-type"), ("scheme","onix:codelist5")] $ x]) (schemeToOnix `fmap` scheme) toCreatorNode s id' creator | version == EPUB2 = [dcNode s ! (("id",id') : maybe [] (\x -> [("opf:file-as",x)]) (creatorFileAs creator) ++ maybe [] (\x -> [("opf:role",x)]) (creatorRole creator >>= toRelator)) $ creatorText creator] | otherwise = [dcNode s ! [("id",id')] $ creatorText creator] ++ maybe [] (\x -> [unode "meta" ! [("refines",'#':id'),("property","file-as")] $ x]) (creatorFileAs creator) ++ maybe [] (\x -> [unode "meta" ! [("refines",'#':id'),("property","role"), ("scheme","marc:relators")] $ x]) (creatorRole creator >>= toRelator) toTitleNode id' title | version == EPUB2 = [dcNode "title" ! (("id",id') : -- note: EPUB2 doesn't accept opf:title-type maybe [] (\x -> [("opf:file-as",x)]) (titleFileAs title)) $ titleText title] | otherwise = [dcNode "title" ! [("id",id')] $ titleText title] ++ maybe [] (\x -> [unode "meta" ! [("refines",'#':id'),("property","file-as")] $ x]) (titleFileAs title) ++ maybe [] (\x -> [unode "meta" ! [("refines",'#':id'),("property","title-type")] $ x]) (titleType title) toDateNode id' date = [dcNode "date" ! (("id",id') : maybe [] (\x -> [("opf:event",x)]) (dateEvent date)) $ dateText date] schemeToOnix "ISBN-10" = "02" schemeToOnix "GTIN-13" = "03" schemeToOnix "UPC" = "04" schemeToOnix "ISMN-10" = "05" schemeToOnix "DOI" = "06" schemeToOnix "LCCN" = "13" schemeToOnix "GTIN-14" = "14" schemeToOnix "ISBN-13" = "15" schemeToOnix "Legal deposit number" = "17" schemeToOnix "URN" = "22" schemeToOnix "OCLC" = "23" schemeToOnix "ISMN-13" = "25" schemeToOnix "ISBN-A" = "26" schemeToOnix "JP" = "27" schemeToOnix "OLCC" = "28" schemeToOnix _ = "01" showDateTimeISO8601 :: UTCTime -> String showDateTimeISO8601 = formatTime defaultTimeLocale "%FT%TZ" transformTag :: PandocMonad m => Tag String -> E m (Tag String) transformTag tag@(TagOpen name attr) | name `elem` ["video", "source", "img", "audio"] && isNothing (lookup "data-external" attr) = do let src = fromAttrib "src" tag let poster = fromAttrib "poster" tag newsrc <- modifyMediaRef src newposter <- modifyMediaRef poster let attr' = filter (\(x,_) -> x /= "src" && x /= "poster") attr ++ [("src", "../" ++ newsrc) | not (null newsrc)] ++ [("poster", "../" ++ newposter) | not (null newposter)] return $ TagOpen name attr' transformTag tag = return tag modifyMediaRef :: PandocMonad m => FilePath -> E m FilePath modifyMediaRef "" = return "" modifyMediaRef oldsrc = do media <- gets stMediaPaths case lookup oldsrc media of Just (n,_) -> return n Nothing -> catchError (do (img, mbMime) <- P.fetchItem oldsrc let new = "media/file" ++ show (length media) ++ fromMaybe (takeExtension (takeWhile (/='?') oldsrc)) (('.':) <$> (mbMime >>= extensionFromMimeType)) entry <- mkEntry new (B.fromChunks . (:[]) $ img) modify $ \st -> st{ stMediaPaths = (oldsrc, (new, Just entry)):media} return new) (\e -> do report $ CouldNotFetchResource oldsrc (show e) return oldsrc) transformBlock :: PandocMonad m => Block -> E m Block transformBlock (RawBlock fmt raw) | fmt == Format "html" = do let tags = parseTags raw tags' <- mapM transformTag tags return $ RawBlock fmt (renderTags' tags') transformBlock b = return b transformInline :: PandocMonad m => WriterOptions -> Inline -> E m Inline transformInline _opts (Image attr lab (src,tit)) = do newsrc <- modifyMediaRef src return $ Image attr lab ("../" ++ newsrc, tit) transformInline opts (x@(Math t m)) | WebTeX url <- writerHTMLMathMethod opts = do newsrc <- modifyMediaRef (url ++ urlEncode m) let mathclass = if t == DisplayMath then "display" else "inline" return $ Span ("",["math",mathclass],[]) [Image nullAttr [x] ("../" ++ newsrc, "")] transformInline _opts (RawInline fmt raw) | fmt == Format "html" = do let tags = parseTags raw tags' <- mapM transformTag tags return $ RawInline fmt (renderTags' tags') transformInline _ x = return x (!) :: (t -> Element) -> [(String, String)] -> t -> Element (!) f attrs n = add_attrs (map (\(k,v) -> Attr (unqual k) v) attrs) (f n) -- | Version of 'ppTopElement' that specifies UTF-8 encoding. ppTopElement :: Element -> String ppTopElement = ("\n" ++) . unEntity . ppElement -- unEntity removes numeric entities introduced by ppElement -- (kindlegen seems to choke on these). where unEntity [] = "" unEntity ('&':'#':xs) = let (ds,ys) = break (==';') xs rest = drop 1 ys in case safeRead ('\'':'\\':ds ++ "'") of Just x -> x : unEntity rest Nothing -> '&':'#':unEntity xs unEntity (x:xs) = x : unEntity xs mediaTypeOf :: FilePath -> Maybe MimeType mediaTypeOf x = let mediaPrefixes = ["image", "video", "audio"] in case getMimeType x of Just y | any (`isPrefixOf` y) mediaPrefixes -> Just y _ -> Nothing -- Returns filename for chapter number. showChapter :: Int -> String showChapter = printf "ch%03d.xhtml" -- Add identifiers to any headers without them. addIdentifiers :: WriterOptions -> [Block] -> [Block] addIdentifiers opts bs = evalState (mapM go bs) Set.empty where go (Header n (ident,classes,kvs) ils) = do ids <- get let ident' = if null ident then uniqueIdent (writerExtensions opts) ils ids else ident modify $ Set.insert ident' return $ Header n (ident',classes,kvs) ils go x = return x -- Variant of normalizeDate that allows partial dates: YYYY, YYYY-MM normalizeDate' :: String -> Maybe String normalizeDate' xs = let xs' = trim xs in case xs' of [y1,y2,y3,y4] | all isDigit [y1,y2,y3,y4] -> Just xs' -- YYYY [y1,y2,y3,y4,'-',m1,m2] | all isDigit [y1,y2,y3,y4,m1,m2] -- YYYY-MM -> Just xs' _ -> normalizeDate xs' toRelator :: String -> Maybe String toRelator x | x `elem` relators = Just x | otherwise = lookup (map toLower x) relatorMap relators :: [String] relators = map snd relatorMap relatorMap :: [(String, String)] relatorMap = [("abridger", "abr") ,("actor", "act") ,("adapter", "adp") ,("addressee", "rcp") ,("analyst", "anl") ,("animator", "anm") ,("annotator", "ann") ,("appellant", "apl") ,("appellee", "ape") ,("applicant", "app") ,("architect", "arc") ,("arranger", "arr") ,("art copyist", "acp") ,("art director", "adi") ,("artist", "art") ,("artistic director", "ard") ,("assignee", "asg") ,("associated name", "asn") ,("attributed name", "att") ,("auctioneer", "auc") ,("author", "aut") ,("author in quotations or text abstracts", "aqt") ,("author of afterword, colophon, etc.", "aft") ,("author of dialog", "aud") ,("author of introduction, etc.", "aui") ,("autographer", "ato") ,("bibliographic antecedent", "ant") ,("binder", "bnd") ,("binding designer", "bdd") ,("blurb writer", "blw") ,("book designer", "bkd") ,("book producer", "bkp") ,("bookjacket designer", "bjd") ,("bookplate designer", "bpd") ,("bookseller", "bsl") ,("braille embosser", "brl") ,("broadcaster", "brd") ,("calligrapher", "cll") ,("cartographer", "ctg") ,("caster", "cas") ,("censor", "cns") ,("choreographer", "chr") ,("cinematographer", "cng") ,("client", "cli") ,("collection registrar", "cor") ,("collector", "col") ,("collotyper", "clt") ,("colorist", "clr") ,("commentator", "cmm") ,("commentator for written text", "cwt") ,("compiler", "com") ,("complainant", "cpl") ,("complainant-appellant", "cpt") ,("complainant-appellee", "cpe") ,("composer", "cmp") ,("compositor", "cmt") ,("conceptor", "ccp") ,("conductor", "cnd") ,("conservator", "con") ,("consultant", "csl") ,("consultant to a project", "csp") ,("contestant", "cos") ,("contestant-appellant", "cot") ,("contestant-appellee", "coe") ,("contestee", "cts") ,("contestee-appellant", "ctt") ,("contestee-appellee", "cte") ,("contractor", "ctr") ,("contributor", "ctb") ,("copyright claimant", "cpc") ,("copyright holder", "cph") ,("corrector", "crr") ,("correspondent", "crp") ,("costume designer", "cst") ,("court governed", "cou") ,("court reporter", "crt") ,("cover designer", "cov") ,("creator", "cre") ,("curator", "cur") ,("dancer", "dnc") ,("data contributor", "dtc") ,("data manager", "dtm") ,("dedicatee", "dte") ,("dedicator", "dto") ,("defendant", "dfd") ,("defendant-appellant", "dft") ,("defendant-appellee", "dfe") ,("degree granting institution", "dgg") ,("delineator", "dln") ,("depicted", "dpc") ,("depositor", "dpt") ,("designer", "dsr") ,("director", "drt") ,("dissertant", "dis") ,("distribution place", "dbp") ,("distributor", "dst") ,("donor", "dnr") ,("draftsman", "drm") ,("dubious author", "dub") ,("editor", "edt") ,("editor of compilation", "edc") ,("editor of moving image work", "edm") ,("electrician", "elg") ,("electrotyper", "elt") ,("enacting jurisdiction", "enj") ,("engineer", "eng") ,("engraver", "egr") ,("etcher", "etr") ,("event place", "evp") ,("expert", "exp") ,("facsimilist", "fac") ,("field director", "fld") ,("film director", "fmd") ,("film distributor", "fds") ,("film editor", "flm") ,("film producer", "fmp") ,("filmmaker", "fmk") ,("first party", "fpy") ,("forger", "frg") ,("former owner", "fmo") ,("funder", "fnd") ,("geographic information specialist", "gis") ,("honoree", "hnr") ,("host", "hst") ,("host institution", "his") ,("illuminator", "ilu") ,("illustrator", "ill") ,("inscriber", "ins") ,("instrumentalist", "itr") ,("interviewee", "ive") ,("interviewer", "ivr") ,("inventor", "inv") ,("issuing body", "isb") ,("judge", "jud") ,("jurisdiction governed", "jug") ,("laboratory", "lbr") ,("laboratory director", "ldr") ,("landscape architect", "lsa") ,("lead", "led") ,("lender", "len") ,("libelant", "lil") ,("libelant-appellant", "lit") ,("libelant-appellee", "lie") ,("libelee", "lel") ,("libelee-appellant", "let") ,("libelee-appellee", "lee") ,("librettist", "lbt") ,("licensee", "lse") ,("licensor", "lso") ,("lighting designer", "lgd") ,("lithographer", "ltg") ,("lyricist", "lyr") ,("manufacture place", "mfp") ,("manufacturer", "mfr") ,("marbler", "mrb") ,("markup editor", "mrk") ,("metadata contact", "mdc") ,("metal-engraver", "mte") ,("moderator", "mod") ,("monitor", "mon") ,("music copyist", "mcp") ,("musical director", "msd") ,("musician", "mus") ,("narrator", "nrt") ,("onscreen presenter", "osp") ,("opponent", "opn") ,("organizer of meeting", "orm") ,("originator", "org") ,("other", "oth") ,("owner", "own") ,("panelist", "pan") ,("papermaker", "ppm") ,("patent applicant", "pta") ,("patent holder", "pth") ,("patron", "pat") ,("performer", "prf") ,("permitting agency", "pma") ,("photographer", "pht") ,("plaintiff", "ptf") ,("plaintiff-appellant", "ptt") ,("plaintiff-appellee", "pte") ,("platemaker", "plt") ,("praeses", "pra") ,("presenter", "pre") ,("printer", "prt") ,("printer of plates", "pop") ,("printmaker", "prm") ,("process contact", "prc") ,("producer", "pro") ,("production company", "prn") ,("production designer", "prs") ,("production manager", "pmn") ,("production personnel", "prd") ,("production place", "prp") ,("programmer", "prg") ,("project director", "pdr") ,("proofreader", "pfr") ,("provider", "prv") ,("publication place", "pup") ,("publisher", "pbl") ,("publishing director", "pbd") ,("puppeteer", "ppt") ,("radio director", "rdd") ,("radio producer", "rpc") ,("recording engineer", "rce") ,("recordist", "rcd") ,("redaktor", "red") ,("renderer", "ren") ,("reporter", "rpt") ,("repository", "rps") ,("research team head", "rth") ,("research team member", "rtm") ,("researcher", "res") ,("respondent", "rsp") ,("respondent-appellant", "rst") ,("respondent-appellee", "rse") ,("responsible party", "rpy") ,("restager", "rsg") ,("restorationist", "rsr") ,("reviewer", "rev") ,("rubricator", "rbr") ,("scenarist", "sce") ,("scientific advisor", "sad") ,("screenwriter", "aus") ,("scribe", "scr") ,("sculptor", "scl") ,("second party", "spy") ,("secretary", "sec") ,("seller", "sll") ,("set designer", "std") ,("setting", "stg") ,("signer", "sgn") ,("singer", "sng") ,("sound designer", "sds") ,("speaker", "spk") ,("sponsor", "spn") ,("stage director", "sgd") ,("stage manager", "stm") ,("standards body", "stn") ,("stereotyper", "str") ,("storyteller", "stl") ,("supporting host", "sht") ,("surveyor", "srv") ,("teacher", "tch") ,("technical director", "tcd") ,("television director", "tld") ,("television producer", "tlp") ,("thesis advisor", "ths") ,("transcriber", "trc") ,("translator", "trl") ,("type designer", "tyd") ,("typographer", "tyg") ,("university place", "uvp") ,("videographer", "vdg") ,("witness", "wit") ,("wood engraver", "wde") ,("woodcutter", "wdc") ,("writer of accompanying material", "wam") ,("writer of added commentary", "wac") ,("writer of added lyrics", "wal") ,("writer of added text", "wat") ] docTitle' :: Meta -> [Inline] docTitle' meta = fromMaybe [] $ go <$> lookupMeta "title" meta where go (MetaString s) = [Str s] go (MetaInlines xs) = xs go (MetaBlocks [Para xs]) = xs go (MetaBlocks [Plain xs]) = xs go (MetaMap m) = case M.lookup "type" m of Just x | stringify x == "main" -> maybe [] go $ M.lookup "text" m _ -> [] go (MetaList xs) = concatMap go xs go _ = []