diff --git a/README b/README index 7efc00e26..22bce6de9 100644 --- a/README +++ b/README @@ -174,14 +174,16 @@ General options (Slidy HTML and javascript slide show), `slideous` (Slideous HTML and javascript slide show), `dzslides` (DZSlides HTML5 + javascript slide show), `revealjs` (reveal.js HTML5 + javascript slide show), `s5` - (S5 HTML and javascript slide show). Note that `odt`, `epub`, and - `epub3` output will not be directed to *stdout*; an output - filename must be specified using the `-o/--output` option. If `+lhs` is - appended to `markdown`, `rst`, `latex`, `beamer`, `html`, or `html5`, the - output will be rendered as literate Haskell source: see [Literate Haskell - support](#literate-haskell-support), below. Markdown syntax extensions can - be individually enabled or disabled by appending `+EXTENSION` or - `-EXTENSION` to the format name, as described above under `-f`. + (S5 HTML and javascript slide show), or the path of a custom + lua writer (see [Custom writers](#custom-writers), below). Note that + `odt`, `epub`, and `epub3` output will not be directed to *stdout*; an + output filename must be specified using the `-o/--output` option. If + `+lhs` is appended to `markdown`, `rst`, `latex`, `beamer`, `html`, or + `html5`, the output will be rendered as literate Haskell source: see + [Literate Haskell support](#literate-haskell-support), below. Markdown + syntax extensions can be individually enabled or disabled by appending + `+EXTENSION` or `-EXTENSION` to the format name, as described above + under `-f`. `-o` *FILE*, `--output=`*FILE* : Write output to *FILE* instead of *stdout*. If *FILE* is @@ -301,6 +303,10 @@ General writer options : Print the default template for an output *FORMAT*. (See `-t` for a list of possible *FORMAT*s.) +`--print-sample-lua-writer` +: Print a sample lua custom writer (see [Custom writers](#custom-writers), + below. + `--no-wrap` : Disable text wrapping in output. By default, text is wrapped appropriately for the output format. @@ -2622,6 +2628,23 @@ ordinary HTML (without bird tracks). writes HTML with the Haskell code in bird tracks, so it can be copied and pasted as literate Haskell source. +Custom writers +============== + +Pandoc can be extended with custom writers written in [lua]. (Pandoc +includes a lua interpreter, so lua need not be installed separately.) + +To use a custom writer, simply specify the path to the lua script +in place of the output format. For example: + + pandoc -t data/sample.lua + +Creating a custom writer requires writing a lua function for each +possible element in a pandoc document. To get a documented example +which you can modify according to your needs, do + + pandoc --print-sample-lua-writer + Authors ======= @@ -2668,3 +2691,5 @@ Sergey Astanin, Arlo O'Keeffe, Denis Laxalde, Brent Yorgey. [PDF]: http://www.adobe.com/pdf/ [reveal.js]: http://lab.hakim.se/reveal-js/ [FictionBook2]: http://www.fictionbook.org/index.php/Eng:XML_Schema_Fictionbook_2.1 +[lua]: TODO + diff --git a/data/sample.lua b/data/sample.lua new file mode 100644 index 000000000..fe425b749 --- /dev/null +++ b/data/sample.lua @@ -0,0 +1,312 @@ +-- This is a sample custom writer for pandoc. It produces output +-- that is very similar to that of pandoc's HTML writer. +-- There is one new feature: code blocks marked with class 'dot' +-- are piped through graphviz and images are included in the HTML +-- output using 'data:' URLs. +-- +-- Invoke with: pandoc -t sample.lua +-- +-- Note: you need not have lua installed on your system to use this +-- custom writer. However, if you do have lua installed, you can +-- use it to test changes to the script. 'lua sample.lua' will +-- produce informative error messages if your code contains +-- syntax errors. + +-- Character escaping +local function escape(s, in_attribute) + return s:gsub("[<>&\"']", + function(x) + if x == '<' then + return '<' + elseif x == '>' then + return '>' + elseif x == '&' then + return '&' + elseif x == '"' then + return '"' + elseif x == "'" then + return ''' + else + return x + end + end) +end + +-- Helper function to convert an attributes table into +-- a string that can be put into HTML tags. +local function attributes(attr) + local attr_table = {} + for x,y in pairs(attr) do + if y and y ~= "" then + table.insert(attr_table, ' ' .. x .. '="' .. escape(y,true) .. '"') + end + end + return table.concat(attr_table) +end + +-- Run cmd on a temporary file containing inp and return result. +local function pipe(cmd, inp) + local tmp = os.tmpname() + local tmph = io.open(tmp, "w") + tmph:write(inp) + tmph:close() + local outh = io.popen(cmd .. " " .. tmp,"r") + local result = outh:read("*all") + outh:close() + os.remove(tmp) + return result +end + +-- Table to store footnotes, so they can be included at the end. +local notes = {} + +-- Blocksep is used to separate block elements. +function Blocksep() + return "\n\n" +end + +-- This function is called once for the whole document. Parameters: +-- body, title, date are strings; authors is an array of strings; +-- variables is a table. One could use some kind of templating +-- system here; this just gives you a simple standalone HTML file. +function Doc(body, title, authors, date, variables) + local buffer = {} + local function add(s) + table.insert(buffer, s) + end + add('') + add('') + add('') + add('' .. title .. '') + add('') + add('') + if title ~= "" then + add('

' .. title .. '

') + end + for _, author in pairs(authors) do + add('

' .. author .. '

') + end + if date ~= "" then + add('

' .. date .. '

') + end + add(body) + if #notes > 0 then + add('
    ') + for _,note in pairs(notes) do + add(note) + end + add('
') + end + add('') + add('') + return table.concat(buffer,'\n') +end + +-- The functions that follow render corresponding pandoc elements. +-- s is always a string, attr is always a table of attributes, and +-- items is always an array of strings (the items in a list). +-- Comments indicate the types of other variables. + +function Str(s) + return escape(s) +end + +function Space() + return " " +end + +function LineBreak() + return "
" +end + +function Emph(s) + return "" .. s .. "" +end + +function Strong(s) + return "" .. s .. "" +end + +function Subscript(s) + return "" .. s .. "" +end + +function Superscript(s) + return "" .. s .. "" +end + +function SmallCaps(s) + return '' .. s .. '' +end + +function Strikeout(s) + return '' .. s .. '' +end + +function Link(s, src, tit) + return "" .. s .. "" +end + +function Image(s, src, tit) + return "" +end + +function Code(s, attr) + return "" .. escape(s) .. "" +end + +function InlineMath(s) + return "\\(" .. escape(s) .. "\\)" +end + +function DisplayMath(s) + return "\\[" .. escape(s) .. "\\]" +end + +function Note(s) + local num = #notes + 1 + -- insert the back reference right before the final closing tag. + s = string.gsub(s, + '(.*)↩' .. s .. '') + -- return the footnote reference, linked to the note. + return '' .. num .. '' +end + +function Plain(s) + return s +end + +function Para(s) + return "

" .. s .. "

" +end + +-- lev is an integer, the header level. +function Header(lev, s, attr) + return "" .. s .. "" +end + +function BlockQuote(s) + return "
\n" .. s .. "\n
" +end + +function HorizontalRule() + return "
" +end + +function CodeBlock(s, attr) + -- If code block has class 'dot', pipe the contents through dot + -- and base64, and include the base64-encoded png as a data: URL. + if attr.class and string.match(' ' .. attr.class .. ' ',' dot ') then + local png = pipe("base64", pipe("dot -Tpng", s)) + return '' + -- otherwise treat as code (one could pipe through a highlighter) + else + return "
" .. escape(s) ..
+           "
" + end +end + +function BulletList(items) + local buffer = {} + for _, item in pairs(items) do + table.insert(buffer, "
  • " .. item .. "
    • ") + end + return "" +end + +function OrderedList(items) + local buffer = {} + for _, item in pairs(items) do + table.insert(buffer, "
  • " .. item .. "
    • ") + end + return "
      \n" .. table.concat(buffer, "\n") .. "\n
    " +end + +-- Revisit association list STackValue instance. +function DefinitionList(items) + local buffer = {} + for _,item in pairs(items) do + for k, v in pairs(item) do + table.insert(buffer,"
    " .. k .. "
    \n
    " .. + table.concat(v,"
    \n
    ") .. "
    ") + end + end + return "
    \n" .. table.concat(buffer, "\n") .. "\n
    " +end + +-- Convert pandoc alignment to something HTML can use. +-- align is AlignLeft, AlignRight, AlignCenter, or AlignDefault. +function html_align(align) + if align == 'AlignLeft' then + return 'left' + elseif align == 'AlignRight' then + return 'right' + elseif align == 'AlignCenter' then + return 'center' + else + return 'left' + end +end + +-- Caption is a string, aligns is an array of strings, +-- widths is an array of floats, headers is an array of +-- strings, rows is an array of arrays of strings. +function Table(caption, aligns, widths, headers, rows) + local buffer = {} + local function add(s) + table.insert(buffer, s) + end + add("") + if caption ~= "" then + add("") + end + if widths and widths[1] ~= 0 then + for _, w in pairs(widths) do + add('') + end + end + local header_row = {} + local empty_header = true + for i, h in pairs(headers) do + local align = html_align(aligns[i]) + table.insert(header_row,'') + empty_header = empty_header and h == "" + end + if empty_header then + head = "" + else + add('') + for _,h in pairs(header_row) do + add(h) + end + add('') + end + local class = "even" + for _, row in pairs(rows) do + class = (class == "even" and "odd") or "even" + add('') + for i,c in pairs(row) do + add('') + end + add('') + end + add('= 0.4 && < 0.6, temporary >= 1.1 && < 1.2, blaze-html >= 0.5 && < 0.7, - blaze-markup >= 0.5.1 && < 0.6 + blaze-markup >= 0.5.1 && < 0.6, + hslua >= 0.3 && < 0.4 if flag(embed_data_files) cpp-options: -DEMBED_DATA_FILES -- build-tools: hsb2hs @@ -305,6 +308,7 @@ Library Text.Pandoc.Writers.RST, Text.Pandoc.Writers.Org, Text.Pandoc.Writers.AsciiDoc, + Text.Pandoc.Writers.Custom, Text.Pandoc.Writers.Textile, Text.Pandoc.Writers.MediaWiki, Text.Pandoc.Writers.RTF, diff --git a/pandoc.hs b/pandoc.hs index 7608ad017..1836fe345 100644 --- a/pandoc.hs +++ b/pandoc.hs @@ -327,6 +327,14 @@ options = "FORMAT") "" -- "Print default template for FORMAT" + , Option "" ["print-sample-lua-writer"] + (NoArg + (\_ -> do + sample <- readDataFileUTF8 Nothing "sample.lua" + UTF8.hPutStr stdout sample + exitWith ExitSuccess)) + "" -- "Print sample lua custom writer" + , Option "" ["no-wrap"] (NoArg (\opt -> return opt { optWrapText = False })) diff --git a/src/Text/Pandoc.hs b/src/Text/Pandoc.hs index cd2aa0fd3..0d1d6375e 100644 --- a/src/Text/Pandoc.hs +++ b/src/Text/Pandoc.hs @@ -99,6 +99,7 @@ module Text.Pandoc , writeFB2 , writeOrg , writeAsciiDoc + , writeCustom -- * Rendering templates and default templates , module Text.Pandoc.Templates -- * Version @@ -142,11 +143,12 @@ import Text.Pandoc.Writers.MediaWiki import Text.Pandoc.Writers.Textile import Text.Pandoc.Writers.Org import Text.Pandoc.Writers.AsciiDoc +import Text.Pandoc.Writers.Custom import Text.Pandoc.Templates import Text.Pandoc.Options import Text.Pandoc.Shared (safeRead, warn) import Data.ByteString.Lazy (ByteString) -import Data.List (intercalate) +import Data.List (intercalate, isSuffixOf) import Data.Version (showVersion) import Text.JSON.Generic import Data.Set (Set) @@ -286,7 +288,10 @@ getWriter s = Left e -> Left $ intercalate "\n" $ [m | Message m <- errorMessages e] Right (writerName, setExts) -> case lookup writerName writers of - Nothing -> Left $ "Unknown writer: " ++ writerName + Nothing + | ".lua" `isSuffixOf` s -> + Right $ IOStringWriter $ writeCustom s + | otherwise -> Left $ "Unknown writer: " ++ writerName Just (PureStringWriter r) -> Right $ PureStringWriter $ \o -> r o{ writerExtensions = setExts $ getDefaultExtensions writerName } diff --git a/src/Text/Pandoc/Writers/Custom.hs b/src/Text/Pandoc/Writers/Custom.hs new file mode 100644 index 000000000..fc16a057e --- /dev/null +++ b/src/Text/Pandoc/Writers/Custom.hs @@ -0,0 +1,230 @@ +{-# LANGUAGE OverlappingInstances, FlexibleInstances, OverloadedStrings #-} +{-# OPTIONS_GHC -fno-warn-orphans #-} +{- Copyright (C) 2012 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.Custom + Copyright : Copyright (C) 2012 John MacFarlane + License : GNU GPL, version 2 or above + + Maintainer : John MacFarlane + Stability : alpha + Portability : portable + +Conversion of 'Pandoc' documents to custom markup using +a lua writer. +-} +module Text.Pandoc.Writers.Custom ( writeCustom ) where +import Text.Pandoc.Definition +import Text.Pandoc.Options +import Data.List ( intersperse ) +import Scripting.Lua (LuaState, StackValue, callfunc) +import qualified Scripting.Lua as Lua +import Text.Pandoc.UTF8 (fromString, toString) +import Data.ByteString (ByteString) +import qualified Data.ByteString.Char8 as C8 +import Data.Monoid +import qualified Data.Map as M + +attrToMap :: Attr -> M.Map ByteString ByteString +attrToMap (id',classes,keyvals) = M.fromList + $ ("id", fromString id') + : ("class", fromString $ unwords classes) + : map (\(x,y) -> (fromString x, fromString y)) keyvals + +getList :: StackValue a => LuaState -> Int -> IO [a] +getList lua i' = do + continue <- Lua.next lua i' + if continue + then do + next <- Lua.peek lua (-1) + Lua.pop lua 1 + x <- maybe (fail "peek returned Nothing") return next + rest <- getList lua i' + return (x : rest) + else return [] + +instance StackValue ByteString where + push l x = Lua.push l $ C8.unpack x + peek l n = (fmap . fmap) C8.pack (Lua.peek l n) + valuetype _ = Lua.TSTRING + +instance StackValue a => StackValue [a] where + push lua xs = do + Lua.createtable lua (length xs + 1) 0 + let addValue (i, x) = Lua.push lua x >> Lua.rawseti lua (-2) i + mapM_ addValue $ zip [1..] xs + peek lua i = do + top <- Lua.gettop lua + let i' = if i < 0 then top + i + 1 else i + Lua.pushnil lua + lst <- getList lua i' + Lua.pop lua 1 + return (Just lst) + valuetype _ = Lua.TTABLE + +instance (StackValue a, StackValue b) => StackValue (M.Map a b) where + push lua m = do + let xs = M.toList m + Lua.createtable lua (length xs + 1) 0 + let addValue (k, v) = Lua.push lua k >> Lua.push lua v >> + Lua.rawset lua (-3) + mapM_ addValue xs + peek _ _ = undefined -- not needed for our purposes + valuetype _ = Lua.TTABLE + +instance (StackValue a, StackValue b) => StackValue (a,b) where + push lua (k,v) = do + Lua.createtable lua 2 0 + Lua.push lua k + Lua.push lua v + Lua.rawset lua (-3) + peek _ _ = undefined -- not needed for our purposes + valuetype _ = Lua.TTABLE + +instance StackValue [Inline] where + push l ils = Lua.push l . C8.unpack =<< inlineListToCustom l ils + peek _ _ = undefined + valuetype _ = Lua.TSTRING + +instance StackValue [Block] where + push l ils = Lua.push l . C8.unpack =<< blockListToCustom l ils + peek _ _ = undefined + valuetype _ = Lua.TSTRING + +-- | Convert Pandoc to custom markup. +writeCustom :: FilePath -> WriterOptions -> Pandoc -> IO String +writeCustom luaFile opts doc = do + luaScript <- readFile luaFile + lua <- Lua.newstate + Lua.openlibs lua + Lua.loadstring lua luaScript "custom" + Lua.call lua 0 0 + -- TODO - call hierarchicalize, so we have that info + rendered <- docToCustom lua opts doc + Lua.close lua + return $ toString rendered + +docToCustom :: LuaState -> WriterOptions -> Pandoc -> IO ByteString +docToCustom lua opts (Pandoc (Meta title authors date) blocks) = do + title' <- inlineListToCustom lua title + authors' <- mapM (inlineListToCustom lua) authors + date' <- inlineListToCustom lua date + body <- blockListToCustom lua blocks + callfunc lua "Doc" body title' authors' date' (writerVariables opts) + +-- | Convert Pandoc block element to Custom. +blockToCustom :: LuaState -- ^ Lua state + -> Block -- ^ Block element + -> IO ByteString + +blockToCustom _ Null = return "" + +blockToCustom lua (Plain inlines) = callfunc lua "Plain" inlines + +blockToCustom lua (Para [Image txt (src,tit)]) = + callfunc lua "CaptionedImage" src tit txt + +blockToCustom lua (Para inlines) = callfunc lua "Para" inlines + +blockToCustom lua (RawBlock format str) = + callfunc lua "RawBlock" format (fromString str) + +blockToCustom lua HorizontalRule = callfunc lua "HorizontalRule" + +blockToCustom lua (Header level attr inlines) = + callfunc lua "Header" level inlines (attrToMap attr) + +blockToCustom lua (CodeBlock attr str) = + callfunc lua "CodeBlock" (fromString str) (attrToMap attr) + +blockToCustom lua (BlockQuote blocks) = callfunc lua "BlockQuote" blocks + +blockToCustom lua (Table capt aligns widths headers rows') = + callfunc lua "Table" capt (map show aligns) widths headers rows' + +blockToCustom lua (BulletList items) = callfunc lua "BulletList" items + +blockToCustom lua (OrderedList (num,sty,delim) items) = + callfunc lua "OrderedList" items num (show sty) (show delim) + +blockToCustom lua (DefinitionList items) = + callfunc lua "DefinitionList" items + +-- | Convert list of Pandoc block elements to Custom. +blockListToCustom :: LuaState -- ^ Options + -> [Block] -- ^ List of block elements + -> IO ByteString +blockListToCustom lua xs = do + blocksep <- callfunc lua "Blocksep" + bs <- mapM (blockToCustom lua) xs + return $ mconcat $ intersperse blocksep bs + +-- | Convert list of Pandoc inline elements to Custom. +inlineListToCustom :: LuaState -> [Inline] -> IO ByteString +inlineListToCustom lua lst = do + xs <- mapM (inlineToCustom lua) lst + return $ C8.concat xs + +-- | Convert Pandoc inline element to Custom. +inlineToCustom :: LuaState -> Inline -> IO ByteString + +inlineToCustom lua (Str str) = callfunc lua "Str" $ fromString str + +inlineToCustom lua Space = callfunc lua "Space" + +inlineToCustom lua (Emph lst) = callfunc lua "Emph" lst + +inlineToCustom lua (Strong lst) = callfunc lua "Strong" lst + +inlineToCustom lua (Strikeout lst) = callfunc lua "Strikeout" lst + +inlineToCustom lua (Superscript lst) = callfunc lua "Superscript" lst + +inlineToCustom lua (Subscript lst) = callfunc lua "Subscript" lst + +inlineToCustom lua (SmallCaps lst) = callfunc lua "SmallCaps" lst + +inlineToCustom lua (Quoted SingleQuote lst) = callfunc lua "SingleQuoted" lst + +inlineToCustom lua (Quoted DoubleQuote lst) = callfunc lua "DoubleQuoted" lst + +inlineToCustom lua (Cite _ lst) = callfunc lua "Cite" lst + +inlineToCustom lua (Code attr str) = + callfunc lua "Code" (fromString str) (attrToMap attr) + +inlineToCustom lua (Math DisplayMath str) = + callfunc lua "DisplayMath" (fromString str) + +inlineToCustom lua (Math InlineMath str) = + callfunc lua "InlineMath" (fromString str) + +inlineToCustom lua (RawInline format str) = + callfunc lua "RawInline" format (fromString str) + +inlineToCustom lua (LineBreak) = callfunc lua "LineBreak" + +inlineToCustom lua (Link txt (src,tit)) = + callfunc lua "Link" txt (fromString src) (fromString tit) + +inlineToCustom lua (Image alt (src,tit)) = + callfunc lua "Image" alt (fromString src) (fromString tit) + +inlineToCustom lua (Note contents) = callfunc lua "Note" contents +
    " .. caption .. "
    ' .. h .. '
    ' .. c .. '