diff options
Diffstat (limited to 'Text/Pandoc/Writers/HTML.hs')
-rw-r--r-- | Text/Pandoc/Writers/HTML.hs | 462 |
1 files changed, 462 insertions, 0 deletions
diff --git a/Text/Pandoc/Writers/HTML.hs b/Text/Pandoc/Writers/HTML.hs new file mode 100644 index 000000000..41e82272d --- /dev/null +++ b/Text/Pandoc/Writers/HTML.hs @@ -0,0 +1,462 @@ +{- +Copyright (C) 2006-7 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.HTML + Copyright : Copyright (C) 2006-7 John MacFarlane + License : GNU GPL, version 2 or above + + Maintainer : John MacFarlane <jgm@berkeley.edu> + Stability : alpha + Portability : portable + +Conversion of 'Pandoc' documents to HTML. +-} +module Text.Pandoc.Writers.HTML ( writeHtml , writeHtmlString ) where +import Text.Pandoc.Definition +import Text.Pandoc.CharacterReferences ( decodeCharacterReferences ) +import Text.Pandoc.Shared +import Text.Regex ( mkRegex, matchRegex ) +import Numeric ( showHex ) +import Data.Char ( ord, toLower ) +import Data.List ( isPrefixOf, intersperse ) +import qualified Data.Set as S +import Control.Monad.State +import Text.XHtml.Transitional +import Text.Pandoc.Include ( includeStrFrom, asciiMathMLPath ) + +data WriterState = WriterState + { stNotes :: [Html] -- ^ List of notes + , stIds :: [String] -- ^ List of header identifiers + , stMath :: Bool -- ^ Math is used in document + , stCSS :: S.Set String -- ^ CSS to include in header + } deriving Show + +asciiMathMLScript = $(includeStrFrom asciiMathMLPath) + +defaultWriterState :: WriterState +defaultWriterState = WriterState {stNotes= [], stIds = [], + stMath = False, stCSS = S.empty} + +-- Helpers to render HTML with the appropriate function. +render opts = if writerWrapText opts then renderHtml else showHtml +renderFragment opts = if writerWrapText opts + then renderHtmlFragment + else showHtmlFragment + +-- | Convert Pandoc document to Html string. +writeHtmlString :: WriterOptions -> Pandoc -> String +writeHtmlString opts = + if writerStandalone opts + then render opts . writeHtml opts + else renderFragment opts . writeHtml opts + +-- | Convert Pandoc document to Html structure. +writeHtml :: WriterOptions -> Pandoc -> Html +writeHtml opts (Pandoc (Meta tit authors date) blocks) = + let titlePrefix = writerTitlePrefix opts + topTitle = evalState (inlineListToHtml opts tit) defaultWriterState + topTitle' = if null titlePrefix + then topTitle + else titlePrefix +++ " - " +++ topTitle + metadata = thetitle topTitle' +++ + meta ! [httpequiv "Content-Type", + content "text/html; charset=UTF-8"] +++ + meta ! [name "generator", content "pandoc"] +++ + (toHtmlFromList $ + map (\a -> meta ! [name "author", content a]) authors) +++ + (if null date + then noHtml + else meta ! [name "date", content date]) + titleHeader = if writerStandalone opts && not (null tit) && + not (writerS5 opts) + then h1 ! [theclass "title"] $ topTitle + else noHtml + headerBlocks = filter isHeaderBlock blocks + ids = uniqueIdentifiers $ + map (\(Header _ lst) -> lst) headerBlocks + toc = if writerTableOfContents opts + then tableOfContents opts headerBlocks ids + else noHtml + (blocks', newstate) = + runState (blockListToHtml opts blocks) + (defaultWriterState {stIds = ids}) + cssLines = stCSS newstate + css = if S.null cssLines + then noHtml + else style ! [thetype "text/css"] $ primHtml $ + '\n':(unlines $ S.toList cssLines) + math = if stMath newstate + then case writerASCIIMathMLURL opts of + Just path -> script ! [src path, + thetype "text/javascript"] $ + noHtml + Nothing -> script ! + [thetype "text/javascript"] $ + primHtml asciiMathMLScript + else noHtml + head = header $ metadata +++ math +++ css +++ + primHtml (writerHeader opts) + notes = reverse (stNotes newstate) + before = primHtml $ writerIncludeBefore opts + after = primHtml $ writerIncludeAfter opts + thebody = before +++ titleHeader +++ toc +++ blocks' +++ + footnoteSection opts notes +++ after + in if writerStandalone opts + then head +++ body thebody + else thebody + +-- | Construct table of contents from list of header blocks and identifiers. +-- Assumes there are as many identifiers as header blocks. +tableOfContents :: WriterOptions -> [Block] -> [String] -> Html +tableOfContents _ [] _ = noHtml +tableOfContents opts headers ids = + let opts' = opts { writerIgnoreNotes = True } + contentsTree = hierarchicalize headers + contents = evalState (mapM (elementToListItem opts') contentsTree) + (defaultWriterState {stIds = ids}) + in thediv ! [identifier "toc"] $ unordList contents + +-- | Converts an Element to a list item for a table of contents, +-- retrieving the appropriate identifier from state. +elementToListItem :: WriterOptions -> Element -> State WriterState Html +elementToListItem opts (Blk _) = return noHtml +elementToListItem opts (Sec headerText subsecs) = do + st <- get + let ids = stIds st + let (id, rest) = if null ids + then ("", []) + else (head ids, tail ids) + put $ st {stIds = rest} + txt <- inlineListToHtml opts headerText + subHeads <- mapM (elementToListItem opts) subsecs + let subList = if null subHeads + then noHtml + else unordList subHeads + return $ (anchor ! [href ("#" ++ id), identifier ("TOC-" ++ id)] $ txt) +++ + subList + +-- | Convert list of Note blocks to a footnote <div>. +-- Assumes notes are sorted. +footnoteSection :: WriterOptions -> [Html] -> Html +footnoteSection opts notes = + if null notes + then noHtml + else thediv ! [theclass "footnotes"] $ hr +++ (olist << notes) + +-- | Obfuscate a "mailto:" link using Javascript. +obfuscateLink :: WriterOptions -> String -> String -> Html +obfuscateLink opts text src = + let emailRegex = mkRegex "^mailto:([^@]*)@(.*)$" + src' = map toLower src + in case (matchRegex emailRegex src') of + (Just [name, domain]) -> + let domain' = substitute "." " dot " domain + at' = obfuscateChar '@' + (linkText, altText) = + if text == drop 7 src' -- autolink + then ("'<code>'+e+'</code>'", name ++ " at " ++ domain') + else ("'" ++ text ++ "'", text ++ " (" ++ name ++ " at " ++ + domain' ++ ")") + in if writerStrictMarkdown opts + then -- need to use primHtml or &'s are escaped to & in URL + primHtml $ "<a href=\"" ++ (obfuscateString src') + ++ "\">" ++ (obfuscateString text) ++ "</a>" + else (script ! [thetype "text/javascript"] $ + primHtml ("\n<!--\nh='" ++ + obfuscateString domain ++ "';a='" ++ at' ++ "';n='" ++ + obfuscateString name ++ "';e=n+a+h;\n" ++ + "document.write('<a h'+'ref'+'=\"ma'+'ilto'+':'+e+'\">'+" ++ + linkText ++ "+'<\\/'+'a'+'>');\n// -->\n")) +++ + noscript (primHtml $ obfuscateString altText) + _ -> anchor ! [href src] $ primHtml text -- malformed email + +-- | Obfuscate character as entity. +obfuscateChar :: Char -> String +obfuscateChar char = + let num = ord char + numstr = if even num then show num else "x" ++ showHex num "" + in "&#" ++ numstr ++ ";" + +-- | Obfuscate string using entities. +obfuscateString :: String -> String +obfuscateString = concatMap obfuscateChar . decodeCharacterReferences + +-- | True if character is a punctuation character (unicode). +isPunctuation :: Char -> Bool +isPunctuation c = + let c' = ord c + in if c `elem` "!\"'()*,-./:;<>?[\\]`{|}~" || c' >= 0x2000 && c' <= 0x206F || + c' >= 0xE000 && c' <= 0xE0FF + then True + else False + +-- | Add CSS for document header. +addToCSS :: String -> State WriterState () +addToCSS item = do + st <- get + let current = stCSS st + put $ st {stCSS = S.insert item current} + +-- | Convert Pandoc inline list to plain text identifier. +inlineListToIdentifier :: [Inline] -> String +inlineListToIdentifier [] = "" +inlineListToIdentifier (x:xs) = + xAsText ++ inlineListToIdentifier xs + where xAsText = case x of + Str s -> filter (\c -> c == '-' || not (isPunctuation c)) $ + concat $ intersperse "-" $ words $ map toLower s + Emph lst -> inlineListToIdentifier lst + Strikeout lst -> inlineListToIdentifier lst + Superscript lst -> inlineListToIdentifier lst + Subscript lst -> inlineListToIdentifier lst + Strong lst -> inlineListToIdentifier lst + Quoted _ lst -> inlineListToIdentifier lst + Code s -> s + Space -> "-" + EmDash -> "-" + EnDash -> "-" + Apostrophe -> "" + Ellipses -> "" + LineBreak -> "-" + TeX _ -> "" + HtmlInline _ -> "" + Link lst _ -> inlineListToIdentifier lst + Image lst _ -> inlineListToIdentifier lst + Note _ -> "" + +-- | Return unique identifiers for list of inline lists. +uniqueIdentifiers :: [[Inline]] -> [String] +uniqueIdentifiers ls = + let addIdentifier (nonuniqueIds, uniqueIds) l = + let new = inlineListToIdentifier l + matches = length $ filter (== new) nonuniqueIds + new' = new ++ if matches > 0 then ("-" ++ show matches) else "" + in (new:nonuniqueIds, new':uniqueIds) + in reverse $ snd $ foldl addIdentifier ([],[]) ls + +-- | Convert Pandoc block element to HTML. +blockToHtml :: WriterOptions -> Block -> State WriterState Html +blockToHtml opts Null = return $ noHtml +blockToHtml opts (Plain lst) = inlineListToHtml opts lst +blockToHtml opts (Para lst) = inlineListToHtml opts lst >>= (return . paragraph) +blockToHtml opts (RawHtml str) = return $ primHtml str +blockToHtml opts (HorizontalRule) = return $ hr +blockToHtml opts (CodeBlock str) = return $ pre $ thecode << (str ++ "\n") + -- the final \n for consistency with Markdown.pl +blockToHtml opts (BlockQuote blocks) = + -- in S5, treat list in blockquote specially + -- if default is incremental, make it nonincremental; + -- otherwise incremental + if writerS5 opts + then let inc = not (writerIncremental opts) in + case blocks of + [BulletList lst] -> blockToHtml (opts {writerIncremental = inc}) + (BulletList lst) + [OrderedList attribs lst] -> + blockToHtml (opts {writerIncremental = inc}) + (OrderedList attribs lst) + otherwise -> blockListToHtml opts blocks >>= + (return . blockquote) + else blockListToHtml opts blocks >>= (return . blockquote) +blockToHtml opts (Header level lst) = do + contents <- inlineListToHtml opts lst + st <- get + let ids = stIds st + let (id, rest) = if null ids + then ("", []) + else (head ids, tail ids) + put $ st {stIds = rest} + let attribs = if writerStrictMarkdown opts && not (writerTableOfContents opts) + then [] + else [identifier id] + let contents' = if writerTableOfContents opts + then anchor ! [href ("#TOC-" ++ id)] $ contents + else contents + return $ case level of + 1 -> h1 contents' ! attribs + 2 -> h2 contents' ! attribs + 3 -> h3 contents' ! attribs + 4 -> h4 contents' ! attribs + 5 -> h5 contents' ! attribs + 6 -> h6 contents' ! attribs + _ -> paragraph contents' ! attribs +blockToHtml opts (BulletList lst) = do + contents <- mapM (blockListToHtml opts) lst + let attribs = if writerIncremental opts + then [theclass "incremental"] + else [] + return $ unordList ! attribs $ contents +blockToHtml opts (OrderedList (startnum, numstyle, _) lst) = do + contents <- mapM (blockListToHtml opts) lst + let numstyle' = camelCaseToHyphenated $ show numstyle + let attribs = (if writerIncremental opts + then [theclass "incremental"] + else []) ++ + (if startnum /= 1 + then [start startnum] + else []) ++ + (if numstyle /= DefaultStyle + then [theclass numstyle'] + else []) + if numstyle /= DefaultStyle + then addToCSS $ "ol." ++ numstyle' ++ + " { list-style-type: " ++ + numstyle' ++ "; }" + else return () + return $ ordList ! attribs $ contents +blockToHtml opts (DefinitionList lst) = do + contents <- mapM (\(term, def) -> do term' <- inlineListToHtml opts term + def' <- blockListToHtml opts def + return $ (term', def')) lst + let attribs = if writerIncremental opts + then [theclass "incremental"] + else [] + return $ defList ! attribs $ contents +blockToHtml opts (Table capt aligns widths headers rows) = do + let alignStrings = map alignmentToString aligns + captionDoc <- if null capt + then return noHtml + else inlineListToHtml opts capt >>= return . caption + colHeads <- colHeadsToHtml opts alignStrings + widths headers + rows' <- mapM (tableRowToHtml opts alignStrings) rows + return $ table $ captionDoc +++ colHeads +++ rows' + +colHeadsToHtml opts alignStrings widths headers = do + heads <- sequence $ zipWith3 + (\align width item -> tableItemToHtml opts th align width item) + alignStrings widths headers + return $ tr $ toHtmlFromList heads + +alignmentToString alignment = case alignment of + AlignLeft -> "left" + AlignRight -> "right" + AlignCenter -> "center" + AlignDefault -> "left" + +tableRowToHtml opts aligns cols = + (sequence $ zipWith3 (tableItemToHtml opts td) aligns (repeat 0) cols) >>= + return . tr . toHtmlFromList + +tableItemToHtml opts tag align' width item = do + contents <- blockListToHtml opts item + let attrib = [align align'] ++ + if width /= 0 + then [thestyle ("width: " ++ show (truncate (100*width)) ++ + "%;")] + else [] + return $ tag ! attrib $ contents + +blockListToHtml :: WriterOptions -> [Block] -> State WriterState Html +blockListToHtml opts lst = + mapM (blockToHtml opts) lst >>= return . toHtmlFromList + +-- | Convert list of Pandoc inline elements to HTML. +inlineListToHtml :: WriterOptions -> [Inline] -> State WriterState Html +inlineListToHtml opts lst = + mapM (inlineToHtml opts) lst >>= return . toHtmlFromList + +-- | Convert Pandoc inline element to HTML. +inlineToHtml :: WriterOptions -> Inline -> State WriterState Html +inlineToHtml opts inline = + case inline of + (Str str) -> return $ stringToHtml str + (Space) -> return $ stringToHtml " " + (LineBreak) -> return $ br + (EmDash) -> return $ primHtmlChar "mdash" + (EnDash) -> return $ primHtmlChar "ndash" + (Ellipses) -> return $ primHtmlChar "hellip" + (Apostrophe) -> return $ primHtmlChar "rsquo" + (Emph lst) -> inlineListToHtml opts lst >>= return . emphasize + (Strong lst) -> inlineListToHtml opts lst >>= return . strong + (Code str) -> return $ thecode << str + (Strikeout lst) -> addToCSS + ".strikeout { text-decoration: line-through; }" >> + inlineListToHtml opts lst >>= + return . (thespan ! [theclass "strikeout"]) + (Superscript lst) -> inlineListToHtml opts lst >>= return . sup + (Subscript lst) -> inlineListToHtml opts lst >>= return . sub + (Quoted quoteType lst) -> + let (leftQuote, rightQuote) = case quoteType of + SingleQuote -> (primHtmlChar "lsquo", + primHtmlChar "rsquo") + DoubleQuote -> (primHtmlChar "ldquo", + primHtmlChar "rdquo") + in do contents <- inlineListToHtml opts lst + return $ leftQuote +++ contents +++ rightQuote + (TeX str) -> (if writerUseASCIIMathML opts + then modify (\st -> st {stMath = True}) + else return ()) >> return (stringToHtml str) + (HtmlInline str) -> return $ primHtml str + (Link [Code str] (src,tit)) | "mailto:" `isPrefixOf` src -> + return $ obfuscateLink opts str src + (Link txt (src,tit)) | "mailto:" `isPrefixOf` src -> do + linkText <- inlineListToHtml opts txt + return $ obfuscateLink opts (show linkText) src + (Link txt (src,tit)) -> do + linkText <- inlineListToHtml opts txt + return $ anchor ! ([href src] ++ + if null tit then [] else [title tit]) $ + linkText + (Image txt (source,tit)) -> do + alternate <- inlineListToHtml opts txt + let alternate' = renderFragment opts alternate + let attributes = [src source] ++ + (if null tit + then [] + else [title tit]) ++ + if null txt + then [] + else [alt alternate'] + return $ image ! attributes + -- note: null title included, as in Markdown.pl + (Note contents) -> do + st <- get + let notes = stNotes st + let number = (length notes) + 1 + let ref = show number + htmlContents <- blockListToNote opts ref contents + -- push contents onto front of notes + put $ st {stNotes = (htmlContents:notes)} + return $ anchor ! [href ("#fn" ++ ref), + theclass "footnoteRef", + identifier ("fnref" ++ ref)] << + sup << ref + +blockListToNote :: WriterOptions -> String -> [Block] -> State WriterState Html +blockListToNote opts ref blocks = + -- If last block is Para or Plain, include the backlink at the end of + -- that block. Otherwise, insert a new Plain block with the backlink. + let backlink = [HtmlInline $ " <a href=\"#fnref" ++ ref ++ + "\" class=\"footnoteBackLink\"" ++ + " title=\"Jump back to footnote " ++ ref ++ "\">↩</a>"] + blocks' = if null blocks + then [] + else let lastBlock = last blocks + otherBlocks = init blocks + in case lastBlock of + (Para lst) -> otherBlocks ++ + [Para (lst ++ backlink)] + (Plain lst) -> otherBlocks ++ + [Plain (lst ++ backlink)] + _ -> otherBlocks ++ [lastBlock, + Plain backlink] + in do contents <- blockListToHtml opts blocks' + return $ li ! [identifier ("fn" ++ ref)] $ contents + |