aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Readers/Org/DocumentTree.hs
blob: 53ec2ef570c6da178dd3ff28e88f00972302635e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
{-
Copyright (C) 2014-2017 Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>

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
-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE RecordWildCards  #-}
{-# LANGUAGE ViewPatterns     #-}
{- |
   Module      : Text.Pandoc.Readers.Org.DocumentTree
   Copyright   : Copyright (C) 2014-2017 Albert Krewinkel
   License     : GNU GPL, version 2 or above

   Maintainer  : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>

Parsers for org-mode headlines and document subtrees
-}
module Text.Pandoc.Readers.Org.DocumentTree
  ( headline
  , headlineToBlocks
  ) where

import Control.Monad (guard, void)
import Data.Char (toLower, toUpper)
import Data.Maybe (fromMaybe)
import Data.Monoid ((<>))
import Text.Pandoc.Builder (Blocks, Inlines)
import Text.Pandoc.Class (PandocMonad)
import Text.Pandoc.Definition
import Text.Pandoc.Readers.Org.BlockStarts
import Text.Pandoc.Readers.Org.Parsing
import Text.Pandoc.Readers.Org.ParserState

import qualified Text.Pandoc.Builder as B

--
-- Org headers
--
newtype Tag = Tag { fromTag :: String }
  deriving (Show, Eq)

-- | Create a tag containing the given string.
toTag :: String -> Tag
toTag = Tag

-- | The key (also called name or type) of a property.
newtype PropertyKey = PropertyKey { fromKey :: String }
  deriving (Show, Eq, Ord)

-- | Create a property key containing the given string.  Org mode keys are
-- case insensitive and are hence converted to lower case.
toPropertyKey :: String -> PropertyKey
toPropertyKey = PropertyKey . map toLower

-- | The value assigned to a property.
newtype PropertyValue = PropertyValue { fromValue :: String }

-- | Create a property value containing the given string.
toPropertyValue :: String -> PropertyValue
toPropertyValue = PropertyValue

-- | Check whether the property value is non-nil (i.e. truish).
isNonNil :: PropertyValue -> Bool
isNonNil p = map toLower (fromValue p) `notElem` ["()", "{}", "nil"]

-- | Key/value pairs from a PROPERTIES drawer
type Properties = [(PropertyKey, PropertyValue)]

-- | Org mode headline (i.e. a document subtree).
data Headline = Headline
  { headlineLevel      :: Int
  , headlineTodoMarker :: Maybe TodoMarker
  , headlineText       :: Inlines
  , headlineTags       :: [Tag]
  , headlineProperties :: Properties
  , headlineContents   :: Blocks
  , headlineChildren   :: [Headline]
  }

-- | Read an Org mode headline and its contents (i.e. a document subtree).
-- @lvl@ gives the minimum acceptable level of the tree.
headline :: PandocMonad m
         => OrgParser m (F Blocks)
         -> OrgParser m (F Inlines)
         -> Int
         -> OrgParser m (F Headline)
headline blocks inline lvl = try $ do
  level <- headerStart
  guard (lvl <= level)
  todoKw <- optionMaybe todoKeyword
  title <- trimInlinesF . mconcat <$> manyTill inline endOfTitle
  tags  <- option [] headerTags
  newline
  properties <- option mempty propertiesDrawer
  contents   <- blocks
  children   <- many (headline blocks inline (level + 1))
  return $ do
    title'    <- title
    contents' <- contents
    children' <- sequence children
    return $ Headline
      { headlineLevel = level
      , headlineTodoMarker = todoKw
      , headlineText = title'
      , headlineTags = tags
      , headlineProperties = properties
      , headlineContents = contents'
      , headlineChildren = children'
      }
 where
   endOfTitle :: Monad m => OrgParser m ()
   endOfTitle = void . lookAhead $ optional headerTags *> newline

   headerTags :: Monad m => OrgParser m [Tag]
   headerTags = try $
     let tag = many1 (alphaNum <|> oneOf "@%#_") <* char ':'
     in map toTag <$> (skipSpaces *> char ':' *> many1 tag <* skipSpaces)

-- | Convert an Org mode headline (i.e. a document tree) into pandoc's Blocks
headlineToBlocks :: Monad m => Headline -> OrgParser m Blocks
headlineToBlocks hdln@(Headline {..}) = do
  maxHeadlineLevels <- getExportSetting exportHeadlineLevels
  case () of
    _ | any isNoExportTag headlineTags     -> return mempty
    _ | any isArchiveTag  headlineTags     -> archivedHeadlineToBlocks hdln
    _ | isCommentTitle headlineText        -> return mempty
    _ | headlineLevel >= maxHeadlineLevels -> headlineToHeaderWithList hdln
    _ | otherwise                          -> headlineToHeaderWithContents hdln

isNoExportTag :: Tag -> Bool
isNoExportTag = (== toTag "noexport")

isArchiveTag :: Tag -> Bool
isArchiveTag = (== toTag "ARCHIVE")

-- | Check if the title starts with COMMENT.
-- FIXME: This accesses builder internals not intended for use in situations
-- like these.  Replace once keyword parsing is supported.
isCommentTitle :: Inlines -> Bool
isCommentTitle (B.toList -> (Str "COMMENT":_)) = True
isCommentTitle _                               = False

archivedHeadlineToBlocks :: Monad m => Headline -> OrgParser m Blocks
archivedHeadlineToBlocks hdln = do
  archivedTreesOption <- getExportSetting exportArchivedTrees
  case archivedTreesOption of
    ArchivedTreesNoExport     -> return mempty
    ArchivedTreesExport       -> headlineToHeaderWithContents hdln
    ArchivedTreesHeadlineOnly -> headlineToHeader hdln

headlineToHeaderWithList :: Monad m => Headline -> OrgParser m Blocks
headlineToHeaderWithList hdln@(Headline {..}) = do
  maxHeadlineLevels <- getExportSetting exportHeadlineLevels
  header        <- headlineToHeader hdln
  listElements  <- mapM headlineToBlocks headlineChildren
  let listBlock  = if null listElements
                   then mempty
                   else B.orderedList listElements
  let headerText = if maxHeadlineLevels == headlineLevel
                   then header
                   else flattenHeader header
  return $ headerText <> headlineContents <> listBlock
 where
   flattenHeader :: Blocks -> Blocks
   flattenHeader blks =
     case B.toList blks of
       (Header _ _ inlns:_) -> B.para (B.fromList inlns)
       _                    -> mempty

headlineToHeaderWithContents :: Monad m => Headline -> OrgParser m Blocks
headlineToHeaderWithContents hdln@(Headline {..}) = do
  header         <- headlineToHeader hdln
  childrenBlocks <- mconcat <$> mapM headlineToBlocks headlineChildren
  return $ header <> headlineContents <> childrenBlocks

headlineToHeader :: Monad m => Headline -> OrgParser m Blocks
headlineToHeader (Headline {..}) = do
  exportTodoKeyword <- getExportSetting exportWithTodoKeywords
  let todoText    = if exportTodoKeyword
                    then case headlineTodoMarker of
                      Just kw -> todoKeywordToInlines kw <> B.space
                      Nothing -> mempty
                    else mempty
  let text        = tagTitle (todoText <> headlineText) headlineTags
  let propAttr    = propertiesToAttr headlineProperties
  attr           <- registerHeader propAttr headlineText
  return $ B.headerWith attr headlineLevel text

todoKeyword :: Monad m => OrgParser m TodoMarker
todoKeyword = try $ do
  taskStates <- activeTodoMarkers <$> getState
  let kwParser tdm = try $ (tdm <$ string (todoMarkerName tdm) <* spaceChar)
  choice (map kwParser taskStates)

todoKeywordToInlines :: TodoMarker -> Inlines
todoKeywordToInlines tdm =
  let todoText  = todoMarkerName tdm
      todoState = map toLower . show $ todoMarkerState tdm
      classes = [todoState, todoText]
  in B.spanWith (mempty, classes, mempty) (B.str todoText)

propertiesToAttr :: Properties -> Attr
propertiesToAttr properties =
  let
    toStringPair prop = (fromKey (fst prop), fromValue (snd prop))
    customIdKey = toPropertyKey "custom_id"
    classKey    = toPropertyKey "class"
    unnumberedKey = toPropertyKey "unnumbered"
    specialProperties = [customIdKey, classKey, unnumberedKey]
    id'  = fromMaybe mempty . fmap fromValue . lookup customIdKey $ properties
    cls  = fromMaybe mempty . fmap fromValue . lookup classKey    $ properties
    kvs' = map toStringPair . filter ((`notElem` specialProperties) . fst)
           $ properties
    isUnnumbered =
      fromMaybe False . fmap isNonNil . lookup unnumberedKey $ properties
  in
    (id', words cls ++ (if isUnnumbered then ["unnumbered"] else []), kvs')

tagTitle :: Inlines -> [Tag] -> Inlines
tagTitle title tags = title <> (mconcat $ map tagToInline tags)

-- | Convert 
tagToInline :: Tag -> Inlines
tagToInline t = B.spanWith ("", ["tag"], [("data-tag-name", fromTag t)]) mempty

-- | Read a :PROPERTIES: drawer and return the key/value pairs contained
-- within.
propertiesDrawer :: Monad m => OrgParser m Properties
propertiesDrawer = try $ do
  drawerType <- drawerStart
  guard $ map toUpper drawerType == "PROPERTIES"
  manyTill property (try endOfDrawer)
 where
   property :: Monad m => OrgParser m (PropertyKey, PropertyValue)
   property = try $ (,) <$> key <*> value

   key :: Monad m => OrgParser m PropertyKey
   key = fmap toPropertyKey . try $
         skipSpaces *> char ':' *> many1Till nonspaceChar (char ':')

   value :: Monad m => OrgParser m PropertyValue
   value = fmap toPropertyValue . try $
           skipSpaces *> manyTill anyChar (try $ skipSpaces *> newline)

   endOfDrawer :: Monad m => OrgParser m String
   endOfDrawer = try $
     skipSpaces *> stringAnyCase ":END:" <* skipSpaces <* newline