pandoc/src/Text/Pandoc/Writers/HTML.hs
fiddlosopher 7f5638853b HTML writer changes:
+ change in scheme for construction of unique identifiers for headers:
  - all lowercase
  - spaces turn into -, not _
+ TOC items now have their own identifiers, starting with TOC-
+ when there is a TOC, headers link back to the corresponding TOC items,
  rather than the top of the TOC.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@653 788f1e2b-df1e-0410-8736-df70ead52e1b
2007-07-08 17:09:17 +00:00

366 lines
18 KiB
Haskell

{-
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.Shared
import Text.Pandoc.Entities (decodeEntities)
import Text.Regex ( mkRegex, matchRegex )
import Numeric ( showHex )
import Data.Char ( ord, toLower )
import Data.List ( isPrefixOf, partition )
import Control.Monad.State
import Text.XHtml.Strict
type Notes = [Html]
type Ids = [String]
type WriterState = (Notes, Ids)
-- | Convert Pandoc document to Html string.
writeHtmlString :: WriterOptions -> Pandoc -> String
writeHtmlString opts =
if writerStandalone opts
then renderHtml . (writeHtml opts)
else renderHtmlFragment . (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) ([],[])
topTitle' = if null titlePrefix
then topTitle
else titlePrefix +++ " - " +++ topTitle
head = header $ 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]) +++
primHtml (writerHeader opts)
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', (revnotes,_)) =
runState (blockListToHtml opts blocks) ([],ids)
notes = reverse revnotes
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
-- | True if block is a Header block.
isHeaderBlock :: Block -> Bool
isHeaderBlock (Header _ _) = True
isHeaderBlock _ = False
-- | Construct table of contents from list of header blocks and identifiers.
-- Assumes there are as many identifiers as header blocks.
tableOfContents :: WriterOptions -> [Block] -> Ids -> Html
tableOfContents opts headers ids =
let opts' = opts { writerIgnoreNotes = True }
contentsTree = hierarchicalize headers
contents = evalState (mapM (elementToListItem opts') contentsTree)
([],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
(notes, ids) <- get
let (id, rest) = if null ids
then ("",[])
else (head ids, tail ids)
put (notes, 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 -> Notes -> Html
footnoteSection opts notes =
if null notes
then noHtml
else thediv ! [theclass "footnotes"] $
hr +++ (olist << notes)
-- | Obfuscate a "mailto:" link using Javascript.
obfuscateLink :: WriterOptions -> Html -> String -> Html
obfuscateLink opts text src =
let emailRegex = mkRegex "mailto:*([^@]*)@(.*)"
text' = show $ text
src' = map toLower src in
case (matchRegex emailRegex src') of
(Just [name, domain]) ->
let domain' = substitute "." " dot " domain
at' = obfuscateChar '@'
linkText = if src' == ("mailto:" ++ text')
then "e"
else "'" ++ text' ++ "'"
altText = if src' == ("mailto:" ++ text')
then name ++ " at " ++ domain'
else text' ++ " (" ++ name ++ " at " ++
domain' ++ ")" in
if writerStrictMarkdown opts
then -- need to use primHtml or &'s are escaped to &amp; 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] $ text -- malformed email
-- | Obfuscate character as entity.
obfuscateChar :: Char -> String
obfuscateChar char =
let num = ord char in
let numstr = if even num then (show num) else ("x" ++ (showHex num "")) in
"&#" ++ numstr ++ ";"
-- | Obfuscate string using entities.
obfuscateString :: String -> String
obfuscateString = (concatMap obfuscateChar) . decodeEntities
-- | 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 -> map toLower s
Emph 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 block =
case block of
(Null) -> return $ noHtml
(Plain lst) -> inlineListToHtml opts lst
(Para lst) -> inlineListToHtml opts lst >>= (return . paragraph)
(RawHtml str) -> return $ primHtml str
(HorizontalRule) -> return $ hr
(CodeBlock str) -> return $ pre $ thecode << (str ++ "\n")
-- the final \n for consistency with Markdown.pl
(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 lst] -> blockToHtml (opts {writerIncremental = inc})
(OrderedList lst)
otherwise -> blockListToHtml opts blocks >>=
(return . blockquote)
else blockListToHtml opts blocks >>= (return . blockquote)
(Header level lst) -> do contents <- inlineListToHtml opts lst
(notes, ids) <- get
let (id, rest) = if null ids
then ("", [])
else (head ids, tail ids)
put (notes, rest)
let attribs = [identifier id]
let headerHtml = 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
let headerHtml' = if writerTableOfContents opts
then anchor ! [href ("#TOC-" ++ id)] $
headerHtml
else headerHtml
return headerHtml'
(BulletList lst) -> do contents <- mapM (blockListToHtml opts) lst
let attribs = if writerIncremental opts
then [theclass "incremental"]
else []
return $ unordList ! attribs $ contents
(OrderedList lst) -> do contents <- mapM (blockListToHtml opts) lst
let attribs = if writerIncremental opts
then [theclass "incremental"]
else []
return $ ordList ! attribs $ contents
(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
(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 =
do contents <- sequence $ zipWith3 (tableItemToHtml opts td) aligns (repeat 0) cols
return $ tr $ toHtmlFromList contents
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
(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) -> return $ stringToHtml str
(HtmlInline str) -> return $ primHtml str
(Link txt (src,tit)) ->
do linkText <- inlineListToHtml opts txt
return $ if (isPrefixOf "mailto:" src)
then obfuscateLink opts linkText src
else anchor ! ([href src] ++
if null tit
then []
else [title tit]) $
linkText
(Image txt (source,tit)) ->
do alternate <- inlineListToHtml opts txt
let alternate' = renderHtmlFragment alternate
let attributes = [src source, title tit] ++
if null txt then [] else [alt alternate']
return $ image ! attributes
-- note: null title included, as in Markdown.pl
(Note contents) -> do (notes, ids) <- get
let number = (length notes) + 1
let ref = show number
htmlContents <- blockListToNote opts ref contents
put (htmlContents:notes, ids) -- push contents onto front of notes
return $ anchor ! [href ("#fn" ++ ref),
theclass "footnoteRef",
identifier ("fnref" ++ ref)] << sup << ref
blockListToNote :: WriterOptions -> String -> [Block] -> State WriterState Html
blockListToNote opts ref blocks =
do contents <- blockListToHtml opts blocks
let backlink = anchor ! [href ("#fnref" ++ ref), theclass "footnoteBacklink",
title ("Jump back to footnote " ++ ref)] $
(primHtmlChar "#8617")
return $ li ! [identifier ("fn" ++ ref)] $ contents +++ backlink