pandoc/src/Text/Pandoc/Writers/EPUB.hs
2010-07-09 10:58:24 -07:00

283 lines
12 KiB
Haskell

{-
Copyright (C) 2010 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.Writers.EPUB
Copyright : Copyright (C) 2010 John MacFarlane
License : GNU GPL, version 2 or above
Maintainer : John MacFarlane <jgm@berkeley.edu>
Stability : alpha
Portability : portable
Conversion of 'Pandoc' documents to EPUB.
-}
module Text.Pandoc.Writers.EPUB ( writeEPUB ) where
import Data.IORef
import Data.Maybe ( fromMaybe, isNothing )
import Data.List ( findIndices, isPrefixOf )
import System.Environment ( getEnv )
import System.FilePath ( (</>), takeBaseName, takeExtension )
import qualified Data.ByteString.Lazy as B
import Data.ByteString.Lazy.UTF8 ( fromString )
import Codec.Archive.Zip
import System.Time
import Text.Pandoc.Shared hiding ( Element )
import Text.Pandoc.Definition
import Control.Monad (liftM)
import Text.XML.Light hiding (ppTopElement)
import Text.Pandoc.UUID
import Text.Pandoc.Writers.HTML
import Text.Pandoc.Writers.Markdown ( writePlain )
import Data.Char ( toLower )
-- | Produce an EPUB file from a Pandoc document.
writeEPUB :: Maybe String -- ^ EPUB stylesheet specified at command line
-> WriterOptions -- ^ Writer options
-> Pandoc -- ^ Document to convert
-> IO B.ByteString
writeEPUB mbStylesheet opts doc@(Pandoc meta _) = do
(TOD epochtime _) <- getClockTime
let mkEntry path content = toEntry path epochtime content
let opts' = opts{ writerEmailObfuscation = NoObfuscation
, writerStandalone = True
, writerWrapText = False }
let sourceDir = writerSourceDirectory opts'
-- title page
let vars = writerVariables opts'
let tpContent = fromString $ writeHtmlString
opts'{writerTemplate = pageTemplate
,writerVariables = ("titlepage","yes"):vars}
(Pandoc meta [])
let tpEntry = mkEntry "title_page.xhtml" tpContent
-- handle pictures
picsRef <- newIORef []
Pandoc _ blocks <- liftM (processWith transformBlock) $ processWithM
(transformInlines (writerHTMLMathMethod opts) sourceDir picsRef) doc
pics <- readIORef picsRef
let readPicEntry (oldsrc, newsrc) = readEntry [] oldsrc >>= \e ->
return e{ eRelativePath = newsrc }
picEntries <- mapM readPicEntry pics
-- body pages
let isH1 (Header 1 _) = True
isH1 _ = False
let h1Indices = dropWhile (== 0) $ findIndices isH1 blocks
let chunks = splitByIndices h1Indices blocks
let titleize (Header 1 xs : ys) = Pandoc meta{docTitle = xs} ys
titleize xs = Pandoc meta xs
let chapToHtml = writeHtmlString opts'{ writerTemplate = pageTemplate
, writerHTMLMathMethod = PlainMath }
let chapters = map titleize chunks
let chapterToEntry :: Int -> Pandoc -> Entry
chapterToEntry num chap = mkEntry ("ch" ++ show num ++ ".xhtml") $
fromString $ chapToHtml chap
let chapterEntries = zipWith chapterToEntry [1..] chapters
-- contents.opf
lang <- catch (liftM (takeWhile (/='.')) $ getEnv "lang")
(\_ -> return "en-US")
uuid <- getRandomUUID
let chapterNode ent = unode "item" !
[("id", takeBaseName $ eRelativePath ent),
("href", eRelativePath ent),
("media-type", "application/xhtml+xml")] $ ()
let chapterRefNode ent = unode "itemref" !
[("idref", takeBaseName $ eRelativePath ent)] $ ()
let pictureNode ent = unode "item" !
[("id", takeBaseName $ eRelativePath ent),
("href", eRelativePath ent),
("media-type", fromMaybe "application/octet-stream"
$ imageTypeOf $ eRelativePath ent)] $ ()
let plainify t = removeTrailingSpace $
writePlain opts'{ writerStandalone = False } $
Pandoc meta [Plain t]
let plainTitle = plainify $ docTitle meta
let plainAuthors = map plainify $ docAuthors meta
let contentsData = fromString $ ppTopElement $
unode "package" ! [("version","2.0")
,("xmlns","http://www.idpf.org/2007/opf")
,("unique-identifier","BookId")] $
[ metadataElement (writerEPUBMetadata opts')
uuid lang plainTitle plainAuthors
, unode "manifest" $
[ unode "item" ! [("id","ncx"), ("href","toc.ncx")
,("media-type","application/x-dtbncx+xml")] $ ()
, unode "item" ! [("id","style"), ("href","stylesheet.css")
,("media-type","text/css")] $ ()
] ++
map chapterNode (tpEntry : chapterEntries) ++
map pictureNode picEntries
, unode "spine" ! [("toc","ncx")] $
map chapterRefNode (tpEntry : chapterEntries)
]
let contentsEntry = mkEntry "content.opf" contentsData
-- toc.ncx
let navPointNode ent n tit = unode "navPoint" !
[("id", "navPoint-" ++ show n)
,("playOrder", show n)] $
[ unode "navLabel" $ unode "text" tit
, unode "content" ! [("src",
eRelativePath ent)] $ ()
]
let tocData = fromString $ ppTopElement $
unode "ncx" ! [("version","2005-1")
,("xmlns","http://www.daisy.org/z3986/2005/ncx/")] $
[ unode "head"
[ unode "meta" ! [("name","dtb:uid")
,("content", show uuid)] $ ()
, unode "meta" ! [("name","dtb:depth")
,("content", "1")] $ ()
, unode "meta" ! [("name","dtb:totalPageCount")
,("content", "0")] $ ()
, unode "meta" ! [("name","dtb:maxPageNumber")
,("content", "0")] $ ()
]
, unode "docTitle" $ unode "text" $ plainTitle
, unode "navMap" $ zipWith3 navPointNode (tpEntry : chapterEntries)
[1..(length chapterEntries + 1)]
("Title Page" : map (\(Pandoc m _) ->
plainify $ docTitle m) chapters)
]
let tocEntry = mkEntry "toc.ncx" tocData
-- mimetype
let mimetypeEntry = mkEntry "mimetype" $ fromString "application/epub+zip"
-- container.xml
let containerData = fromString $ ppTopElement $
unode "container" ! [("version","1.0")
,("xmlns","urn:oasis:names:tc:opendocument:xmlns:container")] $
unode "rootfiles" $
unode "rootfile" ! [("full-path","content.opf")
,("media-type","application/oebps-package+xml")] $ ()
let containerEntry = mkEntry "META-INF/container.xml" containerData
-- stylesheet
stylesheet <- case mbStylesheet of
Just s -> return s
Nothing -> readDataFile (writerUserDataDir opts) "epub.css"
let stylesheetEntry = mkEntry "stylesheet.css" $ fromString stylesheet
-- construct archive
let archive = foldr addEntryToArchive emptyArchive
(mimetypeEntry : containerEntry : stylesheetEntry : tpEntry :
contentsEntry : tocEntry : (picEntries ++ chapterEntries) )
return $ fromArchive archive
metadataElement :: String -> UUID -> String -> String -> [String] -> Element
metadataElement metadataXML uuid lang title authors =
let userNodes = parseXML metadataXML
elt = unode "metadata" ! [("xmlns:dc","http://purl.org/dc/elements/1.1/")
,("xmlns:opf","http://www.idpf.org/2007/opf")] $
filter isDublinCoreElement $ onlyElems userNodes
dublinElements = ["contributor","coverage","creator","date",
"description","format","identifier","language","publisher",
"relation","rights","source","subject","title","type"]
isDublinCoreElement e = qPrefix (elName e) == Just "dc" &&
qName (elName e) `elem` dublinElements
contains e n = not (null (findElements (QName n Nothing (Just "dc")) e))
newNodes = [ unode "dc:title" title | not (elt `contains` "title") ] ++
[ unode "dc:language" lang | not (elt `contains` "language") ] ++
[ unode "dc:identifier" ! [("id","BookId")] $ show uuid |
not (elt `contains` "identifier") ] ++
[ unode "dc:creator" ! [("opf:role","aut")] $ a | a <- authors ]
in elt{ elContent = elContent elt ++ map Elem newNodes }
transformInlines :: HTMLMathMethod
-> FilePath
-> IORef [(FilePath, FilePath)] -- ^ (oldpath, newpath) images
-> [Inline]
-> IO [Inline]
transformInlines _ _ _ (Image lab (src,_) : xs) | isNothing (imageTypeOf src) =
return $ Emph lab : xs
transformInlines _ sourceDir picsRef (Image lab (src,tit) : xs) = do
pics <- readIORef picsRef
let oldsrc = sourceDir </> src
let ext = takeExtension src
newsrc <- case lookup oldsrc pics of
Just n -> return n
Nothing -> do
let new = "images/img" ++ show (length pics) ++ ext
modifyIORef picsRef ( (oldsrc, new): )
return new
return $ Image lab (newsrc, tit) : xs
transformInlines (MathML _) _ _ (x@(Math _ _) : xs) = do
let writeHtmlInline opts z = removeTrailingSpace $
writeHtmlString opts $ Pandoc (Meta [] [] []) [Plain [z]]
mathml = writeHtmlInline defaultWriterOptions{
writerHTMLMathMethod = MathML Nothing } x
fallback = writeHtmlInline defaultWriterOptions{
writerHTMLMathMethod = PlainMath } x
inOps = "<ops:switch xmlns:ops=\"http://www.idpf.org/2007/ops\">" ++
"<ops:case required-namespace=\"http://www.w3.org/1998/Math/MathML\">" ++
mathml ++ "</ops:case><ops:default>" ++ fallback ++ "</ops:default>" ++
"</ops:switch>"
result = if "<math" `isPrefixOf` mathml then inOps else mathml
return $ HtmlInline result : xs
transformInlines _ _ _ (HtmlInline _ : xs) = return $ Str "" : xs
transformInlines _ _ _ (Link lab (_,_) : xs) = return $ lab ++ xs
transformInlines _ _ _ xs = return xs
transformBlock :: Block -> Block
transformBlock (RawHtml _) = Null
transformBlock x = x
(!) :: Node t => (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 = ("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" ++) . ppElement
imageTypeOf :: FilePath -> Maybe String
imageTypeOf x = case drop 1 (map toLower (takeExtension x)) of
"jpg" -> Just "image/jpeg"
"jpeg" -> Just "image/jpeg"
"jfif" -> Just "image/jpeg"
"png" -> Just "image/png"
"gif" -> Just "image/gif"
"svg" -> Just "image/svg+xml"
_ -> Nothing
pageTemplate :: String
pageTemplate = unlines
[ "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
, "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.1//EN\" \"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd\">"
, "<html xmlns=\"http://www.w3.org/1999/xhtml\">"
, "<head>"
, "<title>$title$</title>"
, "<link href=\"stylesheet.css\" type=\"text/css\" rel=\"stylesheet\" />"
, "</head>"
, "<body>"
, "$if(titlepage)$"
, "<h1 class=\"title\">$title$</h1>"
, "$for(author)$"
, "<h2 class=\"author\">$author$</h2>"
, "$endfor$"
, "$else$"
, "<h1>$title$</h1>"
, "$body$"
, "$endif$"
, "</body>"
, "</html>"
]