path: root/src/Text/Pandoc/Writers/Docbook.hs

{-
Copyright (C) 2006 John MacFarlane <jgm at berkeley dot 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.Docbook
   Copyright   : Copyright (C) 2006 John MacFarlane
   License     : GNU GPL, version 2 or above 

   Maintainer  : John MacFarlane <jgm at berkeley dot edu>
   Stability   : alpha
   Portability : portable

Conversion of 'Pandoc' documents to Docbook XML.
-}
module Text.Pandoc.Writers.Docbook ( writeDocbook) where
import Text.Pandoc.Definition
import Text.Pandoc.Shared
import Text.Pandoc.Entities ( escapeStringForXML )
import Data.Char ( toLower, ord )
import Data.List ( isPrefixOf, partition, drop )
import Text.PrettyPrint.HughesPJ hiding ( Str )


--
-- code to format XML
--

-- | Return a text object with a string of formatted XML attributes. 
attributeList :: [(String, String)] -> Doc
attributeList = text .  concatMap 
  (\(a, b) -> " " ++ escapeStringForXML a ++ "=\"" ++ 
  escapeStringForXML b ++ "\"") 

-- | Put the supplied contents between start and end tags of tagType,
--   with specified attributes and (if specified) indentation.
inTags:: Bool -> String -> [(String, String)] -> Doc -> Doc
inTags isIndented tagType attribs contents = 
  let openTag = char '<' <> text tagType <> attributeList attribs <> 
                char '>'
      closeTag  = text "</" <> text tagType <> char '>' in
  if isIndented
    then openTag $$ nest 2 contents $$ closeTag
    else openTag <> contents <> closeTag

-- | Return a self-closing tag of tagType with specified attributes
selfClosingTag :: String -> [(String, String)] -> Doc
selfClosingTag tagType attribs = 
  char '<' <> text tagType <> attributeList attribs <> text " />" 
 
-- | Put the supplied contents between start and end tags of tagType.
inTagsSimple :: String -> Doc -> Doc
inTagsSimple tagType = inTags False tagType []

-- | Put the supplied contents in indented block btw start and end tags.
inTagsIndented :: String -> Doc -> Doc
inTagsIndented tagType = inTags True tagType []

--
-- Docbook writer
--

-- | Convert list of authors to a docbook <author> section
authorToDocbook :: [Char] -> Doc
authorToDocbook name = inTagsIndented "author" $ 
  if ',' `elem` name
    then -- last name first
      let (lastname, rest) = break (==',') name 
          firstname = removeLeadingSpace rest in
      inTagsSimple "firstname" (text $ escapeStringForXML firstname) <> 
      inTagsSimple "surname" (text $ escapeStringForXML lastname) 
    else -- last name last
      let namewords = words name
          lengthname = length namewords 
          (firstname, lastname) = case lengthname of
            0  -> ("","") 
            1  -> ("", name)
            n  -> (joinWithSep " " (take (n-1) namewords), last namewords) in
       inTagsSimple "firstname" (text $ escapeStringForXML firstname) $$ 
       inTagsSimple "surname" (text $ escapeStringForXML lastname) 

-- | Convert Pandoc document to string in Docbook format.
writeDocbook :: WriterOptions -> Pandoc -> String
writeDocbook opts (Pandoc (Meta title authors date) blocks) = 
  let head = if (writerStandalone opts)
                then text (writerHeader opts)
                else empty
      meta = if (writerStandalone opts)
                then inTagsIndented "articleinfo" $
                     (inTagsSimple "title" (wrap opts title)) $$ 
                     (vcat (map authorToDocbook authors)) $$ 
                     (inTagsSimple "date" (text $ escapeStringForXML date)) 
                else empty
      elements = hierarchicalize blocks
      before = writerIncludeBefore opts
      after = writerIncludeAfter opts
      body = (if null before then empty else text before) $$
             vcat (map (elementToDocbook opts) elements) $$
             (if null after then empty else text after)
      body' = if writerStandalone opts
                then inTagsIndented "article" (meta $$ body)
                else body in  
  render $ head $$ body' $$ text ""

-- | Convert an Element to Docbook.
elementToDocbook :: WriterOptions -> Element -> Doc
elementToDocbook opts (Blk block) = blockToDocbook opts block 
elementToDocbook opts (Sec title elements) =
  -- Docbook doesn't allow sections with no content, so insert some if needed
  let elements' = if null elements
                    then [Blk (Para [])]
                    else elements in 
  inTagsIndented "section" $
  inTagsSimple "title" (wrap opts title) $$
  vcat (map (elementToDocbook opts) elements') 

-- | Convert a list of Pandoc blocks to Docbook.
blocksToDocbook :: WriterOptions -> [Block] -> Doc
blocksToDocbook opts = vcat . map (blockToDocbook opts)

-- | Auxiliary function to convert Plain block to Para.
plainToPara (Plain x) = Para x
plainToPara x = x

-- | Convert a list of pairs of terms and definitions into a list of 
-- Docbook varlistentrys.
deflistItemsToDocbook :: WriterOptions -> [([Inline],[Block])] -> Doc
deflistItemsToDocbook opts items = 
  vcat $ map (\(term, def) -> deflistItemToDocbook opts term def) items

-- | Convert a term and a list of blocks into a Docbook varlistentry.
deflistItemToDocbook :: WriterOptions -> [Inline] -> [Block] -> Doc
deflistItemToDocbook opts term def =
  let def' = map plainToPara def in
  inTagsIndented "varlistentry" $
  inTagsIndented "term" (inlinesToDocbook opts term) $$
  inTagsIndented "listitem" (blocksToDocbook opts def')

-- | Convert a list of lists of blocks to a list of Docbook list items.
listItemsToDocbook :: WriterOptions -> [[Block]] -> Doc
listItemsToDocbook opts items = 
  vcat $ map (listItemToDocbook opts) items

-- | Convert a list of blocks into a Docbook list item.
listItemToDocbook :: WriterOptions -> [Block] -> Doc
listItemToDocbook opts item =
  let item' = map plainToPara item in
  inTagsIndented "listitem" (blocksToDocbook opts item')

-- | Convert a Pandoc block element to Docbook.
blockToDocbook :: WriterOptions -> Block -> Doc
blockToDocbook opts Null = empty
blockToDocbook opts (Plain lst) = wrap opts lst
blockToDocbook opts (Para lst) = 
  inTagsIndented "para" (wrap opts lst)
blockToDocbook opts (BlockQuote blocks) =
  inTagsIndented "blockquote" (blocksToDocbook opts blocks)
blockToDocbook opts (CodeBlock str) = 
  text "<screen>\n" <> text (escapeStringForXML str) <> text "\n</screen>"
blockToDocbook opts (BulletList lst) = 
  inTagsIndented "itemizedlist" $ listItemsToDocbook opts lst 
blockToDocbook opts (OrderedList lst) = 
  inTagsIndented "orderedlist" $ listItemsToDocbook opts lst 
blockToDocbook opts (DefinitionList lst) = 
  inTagsIndented "variablelist" $ deflistItemsToDocbook opts lst 
blockToDocbook opts (RawHtml str) = text str -- raw XML block 
blockToDocbook opts HorizontalRule = empty -- not semantic
blockToDocbook opts (Table caption aligns widths headers rows) =
  let alignStrings = map alignmentToString aligns
      captionDoc   = if null caption
                      then empty
                      else inTagsIndented "caption" 
                           (inlinesToDocbook opts caption)
      tableType   = if isEmpty captionDoc then "informaltable" else "table" in
  inTagsIndented tableType $ captionDoc $$
  (colHeadsToDocbook opts alignStrings widths headers) $$ 
  (vcat $ map (tableRowToDocbook opts alignStrings) rows)

colHeadsToDocbook opts alignStrings widths headers =
  let heads = zipWith3
              (\align width item -> tableItemToDocbook opts "th" align width item) 
              alignStrings widths headers in
  inTagsIndented "tr" $ vcat heads

alignmentToString alignment = case alignment of
                                 AlignLeft -> "left"
                                 AlignRight -> "right"
                                 AlignCenter -> "center"
                                 AlignDefault -> "left"

tableRowToDocbook opts aligns cols =
  inTagsIndented "tr" $ vcat $ zipWith3 (tableItemToDocbook opts "td") aligns (repeat 0) cols

tableItemToDocbook opts tag align width item =
  let attrib = [("align", align)] ++ 
               if (width /= 0) 
                 then [("style", "{width: " ++ 
                                 show (truncate (100*width)) ++ "%;}")]
                 else [] in 
  inTags True tag attrib $ vcat $ map (blockToDocbook opts) item

-- | Put string in CDATA section
cdata :: String -> Doc
cdata str = text $ "<![CDATA[" ++ str ++ "]]>"

-- | Take list of inline elements and return wrapped doc.
wrap :: WriterOptions -> [Inline] -> Doc
wrap opts lst = fsep $ map (inlinesToDocbook opts) (splitBy Space lst)

-- | Convert a list of inline elements to Docbook.
inlinesToDocbook :: WriterOptions -> [Inline] -> Doc
inlinesToDocbook opts lst = hcat (map (inlineToDocbook opts) lst)

-- | Convert an inline element to Docbook.
inlineToDocbook :: WriterOptions -> Inline -> Doc
inlineToDocbook opts (Str str) = text $ escapeStringForXML str 
inlineToDocbook opts (Emph lst) = 
  inTagsSimple "emphasis" (inlinesToDocbook opts lst)
inlineToDocbook opts (Strong lst) = 
  inTags False "emphasis" [("role", "strong")] 
  (inlinesToDocbook opts lst)
inlineToDocbook opts (Quoted _ lst) = 
  inTagsSimple "quote" (inlinesToDocbook opts lst)
inlineToDocbook opts Apostrophe = text "'"
inlineToDocbook opts Ellipses = text "&#8230;"
inlineToDocbook opts EmDash = text "&#8212;" 
inlineToDocbook opts EnDash = text "&#8211;" 
inlineToDocbook opts (Code str) = 
  inTagsSimple "literal" $ text (escapeStringForXML str)
inlineToDocbook opts (TeX str) = inlineToDocbook opts (Code str)
inlineToDocbook opts (HtmlInline str) = empty
inlineToDocbook opts LineBreak = 
  text $ "<literallayout></literallayout>" 
inlineToDocbook opts Space = char ' '
inlineToDocbook opts (Link txt (src, tit)) =
  if isPrefixOf "mailto:" src
    then inTagsSimple "email" $ text (escapeStringForXML $ drop 7 src)
    else inTags False "ulink" [("url", src)] $ inlinesToDocbook opts txt
inlineToDocbook opts (Image alt (src, tit)) = 
  let titleDoc = if null tit
                   then empty
                   else inTagsIndented "objectinfo" $
                        inTagsIndented "title" 
                        (text $ escapeStringForXML tit) in
  inTagsIndented "inlinemediaobject" $ 
  inTagsIndented "imageobject" $
  titleDoc $$ selfClosingTag "imagedata" [("fileref", src)] 
inlineToDocbook opts (Note contents) = 
  inTagsIndented "footnote" $ blocksToDocbook opts contents