From f1d83aea12b93b31f5218bed75bd0e9d8d373cb6 Mon Sep 17 00:00:00 2001
From: Mauro Bieg <mb21@users.noreply.github.com>
Date: Wed, 2 Jan 2019 20:36:37 +0100
Subject: [PATCH] Implement task lists (#5139)
Closes #3051
---
MANUAL.txt | 11 ++-
src/Text/Pandoc/Extensions.hs | 3 +
src/Text/Pandoc/Readers/CommonMark.hs | 7 +-
src/Text/Pandoc/Readers/Markdown.hs | 3 +-
src/Text/Pandoc/Shared.hs | 32 ++++++++
src/Text/Pandoc/Writers/CommonMark.hs | 25 ++++--
src/Text/Pandoc/Writers/HTML.hs | 22 ++++-
src/Text/Pandoc/Writers/LaTeX.hs | 16 +++-
src/Text/Pandoc/Writers/Markdown.hs | 6 +-
test/command/gfm.md | 29 +++++++
test/command/tasklist.md | 113 ++++++++++++++++++++++++++
11 files changed, 247 insertions(+), 20 deletions(-)
create mode 100644 test/command/tasklist.md
diff --git a/MANUAL.txt b/MANUAL.txt
index 9c1f2f9a2..5c7e13e41 100644
--- a/MANUAL.txt
+++ b/MANUAL.txt
@@ -2612,6 +2612,13 @@ If default list markers are desired, use `#.`:
#. two
#. three
+#### Extension: `task_lists` ####
+
+Pandoc supports task lists, using the syntax of GitHub-Flavored Markdown.
+
+ - [ ] an unchecked task list item
+ - [x] checked item
+
### Definition lists ###
@@ -4223,7 +4230,7 @@ variants are supported:
: `pipe_tables`, `raw_html`, `fenced_code_blocks`, `auto_identifiers`,
`gfm_auto_identifiers`, `backtick_code_blocks`,
`autolink_bare_uris`, `space_in_atx_header`,
- `intraword_underscores`, `strikeout`, `emoji`,
+ `intraword_underscores`, `strikeout`, `task_lists`, `emoji`,
`shortcut_reference_links`, `angle_brackets_escapable`,
`lists_without_preceding_blankline`.
@@ -4254,7 +4261,7 @@ only affects `gfm` output, not input.
: `pipe_tables`, `raw_html`, `fenced_code_blocks`, `auto_identifiers`,
`gfm_auto_identifiers`, `backtick_code_blocks`,
`autolink_bare_uris`, `space_in_atx_header`,
- `intraword_underscores`, `strikeout`, `emoji`,
+ `intraword_underscores`, `strikeout`, `task_lists`, `emoji`,
`shortcut_reference_links`, `angle_brackets_escapable`,
`lists_without_preceding_blankline`.
diff --git a/src/Text/Pandoc/Extensions.hs b/src/Text/Pandoc/Extensions.hs
index f2599ed6d..f660cf766 100644
--- a/src/Text/Pandoc/Extensions.hs
+++ b/src/Text/Pandoc/Extensions.hs
@@ -167,6 +167,7 @@ data Extension =
| Ext_subscript -- ^ Subscript using ~this~ syntax
| Ext_superscript -- ^ Superscript using ^this^ syntax
| Ext_styles -- ^ Read styles that pandoc doesn't know
+ | Ext_task_lists -- ^ Parse certain list items as task list items
| Ext_table_captions -- ^ Pandoc-style table captions
| Ext_tex_math_dollars -- ^ TeX math between $..$ or $$..$$
| Ext_tex_math_double_backslash -- ^ TeX math btw \\(..\\) \\[..\\]
@@ -215,6 +216,7 @@ pandocExtensions = extensionsFromList
, Ext_strikeout
, Ext_superscript
, Ext_subscript
+ , Ext_task_lists
, Ext_auto_identifiers
, Ext_header_attributes
, Ext_link_attributes
@@ -274,6 +276,7 @@ githubMarkdownExtensions = extensionsFromList
, Ext_space_in_atx_header
, Ext_intraword_underscores
, Ext_strikeout
+ , Ext_task_lists
, Ext_emoji
, Ext_lists_without_preceding_blankline
, Ext_shortcut_reference_links
diff --git a/src/Text/Pandoc/Readers/CommonMark.hs b/src/Text/Pandoc/Readers/CommonMark.hs
index 3cc75e2a1..0a3f5e51d 100644
--- a/src/Text/Pandoc/Readers/CommonMark.hs
+++ b/src/Text/Pandoc/Readers/CommonMark.hs
@@ -43,7 +43,7 @@ import Text.Pandoc.Class (PandocMonad)
import Text.Pandoc.Definition
import Text.Pandoc.Emoji (emojiToInline)
import Text.Pandoc.Options
-import Text.Pandoc.Shared (uniqueIdent)
+import Text.Pandoc.Shared (uniqueIdent, taskListItemFromAscii)
import Text.Pandoc.Walk (walkM)
-- | Parse a CommonMark formatted string into a 'Pandoc' structure.
@@ -111,12 +111,14 @@ addBlock _ (Node _ (CODE_BLOCK info t) _) =
addBlock opts (Node _ (HEADING lev) nodes) =
(Header lev ("",[],[]) (addInlines opts nodes) :)
addBlock opts (Node _ (LIST listAttrs) nodes) =
- (constructor (map (setTightness . addBlocks opts . children) nodes) :)
+ (constructor (map listItem nodes) :)
where constructor = case listType listAttrs of
BULLET_LIST -> BulletList
ORDERED_LIST -> OrderedList
(start, DefaultStyle, delim)
start = listStart listAttrs
+ listItem = taskListItemFromAscii exts . setTightness
+ . addBlocks opts . children
setTightness = if listTight listAttrs
then map paraToPlain
else id
@@ -125,6 +127,7 @@ addBlock opts (Node _ (LIST listAttrs) nodes) =
delim = case listDelim listAttrs of
PERIOD_DELIM -> Period
PAREN_DELIM -> OneParen
+ exts = readerExtensions opts
addBlock opts (Node _ (TABLE alignments) nodes) =
(Table [] aligns widths headers rows :)
where aligns = map fromTableCellAlignment alignments
diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 94d1157a6..dd1bedc91 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -958,7 +958,8 @@ listItem fourSpaceRule start = try $ do
let raw = concat (first:continuations)
contents <- parseFromString' parseBlocks raw
updateState (\st -> st {stateParserContext = oldContext})
- return contents
+ exts <- getOption readerExtensions
+ return $ B.fromList . taskListItemFromAscii exts . B.toList <$> contents
orderedList :: PandocMonad m => MarkdownParser m (F Blocks)
orderedList = try $ do
diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 9fa083c11..4efdbba61 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -79,6 +79,8 @@ module Text.Pandoc.Shared (
headerShift,
stripEmptyParagraphs,
isTightList,
+ taskListItemFromAscii,
+ taskListItemToAscii,
addMetaField,
makeMeta,
eastAsianLineBreakFilter,
@@ -588,6 +590,36 @@ isTightList = all firstIsPlain
where firstIsPlain (Plain _ : _) = True
firstIsPlain _ = False
+-- | Convert a list item containing tasklist syntax (e.g. @[x]@)
+-- to using @U+2610 BALLOT BOX@ or @U+2612 BALLOT BOX WITH X@.
+taskListItemFromAscii :: Extensions -> [Block] -> [Block]
+taskListItemFromAscii = handleTaskListItem fromMd
+ where
+ fromMd (Str "[" : Space : Str "]" : Space : is) = (Str "☐") : Space : is
+ fromMd (Str "[x]" : Space : is) = (Str "☒") : Space : is
+ fromMd (Str "[X]" : Space : is) = (Str "☒") : Space : is
+ fromMd is = is
+
+-- | Convert a list item containing text starting with @U+2610 BALLOT BOX@
+-- or @U+2612 BALLOT BOX WITH X@ to tasklist syntax (e.g. @[x]@).
+taskListItemToAscii :: Extensions -> [Block] -> [Block]
+taskListItemToAscii = handleTaskListItem toMd
+ where
+ toMd (Str "☐" : Space : is) = rawMd "[ ]" : Space : is
+ toMd (Str "☒" : Space : is) = rawMd "[x]" : Space : is
+ toMd is = is
+ rawMd = RawInline (Format "markdown")
+
+handleTaskListItem :: ([Inline] -> [Inline]) -> Extensions -> [Block] -> [Block]
+handleTaskListItem handleInlines exts bls =
+ if Ext_task_lists `extensionEnabled` exts
+ then handleItem bls
+ else bls
+ where
+ handleItem (Plain is : bs) = Plain (handleInlines is) : bs
+ handleItem (Para is : bs) = Para (handleInlines is) : bs
+ handleItem bs = bs
+
-- | Set a field of a 'Meta' object. If the field already has a value,
-- convert it into a list with the new value appended to the old value(s).
addMetaField :: ToMetaValue a
diff --git a/src/Text/Pandoc/Writers/CommonMark.hs b/src/Text/Pandoc/Writers/CommonMark.hs
index 6299b0263..e28fa71a9 100644
--- a/src/Text/Pandoc/Writers/CommonMark.hs
+++ b/src/Text/Pandoc/Writers/CommonMark.hs
@@ -46,7 +46,8 @@ import Network.HTTP (urlEncode)
import Text.Pandoc.Class (PandocMonad)
import Text.Pandoc.Definition
import Text.Pandoc.Options
-import Text.Pandoc.Shared (isTightList, linesToPara, substitute, capitalize)
+import Text.Pandoc.Shared (isTightList, taskListItemToAscii, linesToPara,
+ substitute, capitalize)
import Text.Pandoc.Templates (renderTemplate')
import Text.Pandoc.Walk (query, walk, walkM)
import Text.Pandoc.Writers.HTML (writeHtml5String, tagWithAttributes)
@@ -115,24 +116,28 @@ blockToNodes opts (Para xs) ns =
blockToNodes opts (LineBlock lns) ns = blockToNodes opts (linesToPara lns) ns
blockToNodes _ (CodeBlock (_,classes,_) xs) ns = return
(node (CODE_BLOCK (T.pack (unwords classes)) (T.pack xs)) [] : ns)
-blockToNodes opts (RawBlock fmt xs) ns
- | fmt == Format "html" && isEnabled Ext_raw_html opts
+blockToNodes opts (RawBlock (Format f) xs) ns
+ | f == "html" && isEnabled Ext_raw_html opts
= return (node (HTML_BLOCK (T.pack xs)) [] : ns)
- | (fmt == Format "latex" || fmt == Format "tex") && isEnabled Ext_raw_tex opts
+ | (f == "latex" || f == "tex") && isEnabled Ext_raw_tex opts
+ = return (node (CUSTOM_BLOCK (T.pack xs) T.empty) [] : ns)
+ | f == "markdown"
= return (node (CUSTOM_BLOCK (T.pack xs) T.empty) [] : ns)
| otherwise = return ns
blockToNodes opts (BlockQuote bs) ns = do
nodes <- blocksToNodes opts bs
return (node BLOCK_QUOTE nodes : ns)
blockToNodes opts (BulletList items) ns = do
- nodes <- mapM (blocksToNodes opts) items
+ let exts = writerExtensions opts
+ nodes <- mapM (blocksToNodes opts . taskListItemToAscii exts) items
return (node (LIST ListAttributes{
listType = BULLET_LIST,
listDelim = PERIOD_DELIM,
listTight = isTightList items,
listStart = 1 }) (map (node ITEM) nodes) : ns)
blockToNodes opts (OrderedList (start, _sty, delim) items) ns = do
- nodes <- mapM (blocksToNodes opts) items
+ let exts = writerExtensions opts
+ nodes <- mapM (blocksToNodes opts . taskListItemToAscii exts) items
return (node (LIST ListAttributes{
listType = ORDERED_LIST,
listDelim = case delim of
@@ -292,10 +297,12 @@ inlineToNodes opts (Image alt ils (url,'f':'i':'g':':':tit)) =
inlineToNodes opts (Image alt ils (url,tit))
inlineToNodes opts (Image _ ils (url,tit)) =
(node (IMAGE (T.pack url) (T.pack tit)) (inlinesToNodes opts ils) :)
-inlineToNodes opts (RawInline fmt xs)
- | fmt == Format "html" && isEnabled Ext_raw_html opts
+inlineToNodes opts (RawInline (Format f) xs)
+ | f == "html" && isEnabled Ext_raw_html opts
= (node (HTML_INLINE (T.pack xs)) [] :)
- | (fmt == Format "latex" || fmt == Format "tex") && isEnabled Ext_raw_tex opts
+ | (f == "latex" || f == "tex") && isEnabled Ext_raw_tex opts
+ = (node (CUSTOM_INLINE (T.pack xs) T.empty) [] :)
+ | f == "markdown"
= (node (CUSTOM_INLINE (T.pack xs) T.empty) [] :)
| otherwise = id
inlineToNodes opts (Quoted qt ils) =
diff --git a/src/Text/Pandoc/Writers/HTML.hs b/src/Text/Pandoc/Writers/HTML.hs
index 8cdadca5b..98b86a7c9 100644
--- a/src/Text/Pandoc/Writers/HTML.hs
+++ b/src/Text/Pandoc/Writers/HTML.hs
@@ -365,6 +365,24 @@ defList :: PandocMonad m
=> WriterOptions -> [Html] -> StateT WriterState m Html
defList opts items = toList H.dl opts (items ++ [nl opts])
+listItemToHtml :: PandocMonad m
+ => WriterOptions -> [Block] -> StateT WriterState m Html
+listItemToHtml opts bls
+ | Plain (Str "☐":Space:is) : bs <- bls = taskListItem False id is bs
+ | Plain (Str "☒":Space:is) : bs <- bls = taskListItem True id is bs
+ | Para (Str "☐":Space:is) : bs <- bls = taskListItem False H.p is bs
+ | Para (Str "☒":Space:is) : bs <- bls = taskListItem True H.p is bs
+ | otherwise = blockListToHtml opts bls
+ where
+ taskListItem checked constr is bs = do
+ let checkbox = if checked
+ then checkbox' ! A.checked ""
+ else checkbox'
+ checkbox' = H.input ! A.type_ "checkbox" ! A.disabled "" >> nl opts
+ isContents <- inlineListToHtml opts is
+ bsContents <- blockListToHtml opts bs
+ return $ constr (checkbox >> isContents) >> bsContents
+
-- | Construct table of contents from list of elements.
tableOfContents :: PandocMonad m => WriterOptions -> [Element]
-> StateT WriterState m (Maybe Html)
@@ -824,10 +842,10 @@ blockToHtml opts (Header level attr@(_,classes,_) lst) = do
6 -> H.h6 contents'
_ -> H.p contents'
blockToHtml opts (BulletList lst) = do
- contents <- mapM (blockListToHtml opts) lst
+ contents <- mapM (listItemToHtml opts) lst
unordList opts contents
blockToHtml opts (OrderedList (startnum, numstyle, _) lst) = do
- contents <- mapM (blockListToHtml opts) lst
+ contents <- mapM (listItemToHtml opts) lst
html5 <- gets stHtml5
let numstyle' = case numstyle of
Example -> "decimal"
diff --git a/src/Text/Pandoc/Writers/LaTeX.hs b/src/Text/Pandoc/Writers/LaTeX.hs
index f9bee886e..7441152a6 100644
--- a/src/Text/Pandoc/Writers/LaTeX.hs
+++ b/src/Text/Pandoc/Writers/LaTeX.hs
@@ -924,8 +924,20 @@ listItemToLaTeX lst
-- this will keep the typesetter from throwing an error.
| (Header{} :_) <- lst =
blockListToLaTeX lst >>= return . (text "\\item ~" $$) . nest 2
- | otherwise = blockListToLaTeX lst >>= return . (text "\\item" $$) .
- nest 2
+ | Plain (Str "☐":Space:is) : bs <- lst = taskListItem False is bs
+ | Plain (Str "☒":Space:is) : bs <- lst = taskListItem True is bs
+ | Para (Str "☐":Space:is) : bs <- lst = taskListItem False is bs
+ | Para (Str "☒":Space:is) : bs <- lst = taskListItem True is bs
+ | otherwise = blockListToLaTeX lst >>= return . (text "\\item" $$) . nest 2
+ where
+ taskListItem checked is bs = do
+ let checkbox = if checked
+ then "$\\boxtimes$"
+ else "$\\square$"
+ isContents <- inlineListToLaTeX is
+ bsContents <- blockListToLaTeX bs
+ return $ "\\item" <> brackets checkbox
+ $$ nest 2 (isContents $+$ bsContents)
defListItemToLaTeX :: PandocMonad m => ([Inline], [[Block]]) -> LW m Doc
defListItemToLaTeX (term, defs) = do
diff --git a/src/Text/Pandoc/Writers/Markdown.hs b/src/Text/Pandoc/Writers/Markdown.hs
index c0c6e8ebf..7babbe982 100644
--- a/src/Text/Pandoc/Writers/Markdown.hs
+++ b/src/Text/Pandoc/Writers/Markdown.hs
@@ -765,7 +765,8 @@ itemEndsWithTightList bs =
-- | Convert bullet list item (list of blocks) to markdown.
bulletListItemToMarkdown :: PandocMonad m => WriterOptions -> [Block] -> MD m Doc
bulletListItemToMarkdown opts bs = do
- contents <- blockListToMarkdown opts bs
+ let exts = writerExtensions opts
+ contents <- blockListToMarkdown opts $ taskListItemToAscii exts bs
let sps = replicate (writerTabStop opts - 2) ' '
let start = text ('-' : ' ' : sps)
-- remove trailing blank line if item ends with a tight list
@@ -781,7 +782,8 @@ orderedListItemToMarkdown :: PandocMonad m
-> [Block] -- ^ list item (list of blocks)
-> MD m Doc
orderedListItemToMarkdown opts marker bs = do
- contents <- blockListToMarkdown opts bs
+ let exts = writerExtensions opts
+ contents <- blockListToMarkdown opts $ taskListItemToAscii exts bs
let sps = case length marker - writerTabStop opts of
n | n > 0 -> text $ replicate n ' '
_ -> text " "
diff --git a/test/command/gfm.md b/test/command/gfm.md
index 7a7098989..a4bb088b6 100644
--- a/test/command/gfm.md
+++ b/test/command/gfm.md
@@ -101,3 +101,32 @@ hi
^D
[Para [Str "hi",LineBreak,Str "hi"]]
```
+
+```
+% pandoc -f gfm -t native
+- [ ] foo
+- [x] bar
+^D
+[BulletList
+ [[Plain [Str "\9744",Space,Str "foo"]]
+ ,[Plain [Str "\9746",Space,Str "bar"]]]]
+```
+
+```
+% pandoc -f gfm-task_lists -t native
+- [ ] foo
+- [x] bar
+^D
+[BulletList
+ [[Plain [Str "[",Space,Str "]",Space,Str "foo"]]
+ ,[Plain [Str "[x]",Space,Str "bar"]]]]
+```
+
+```
+% pandoc -f gfm -t gfm
+- [ ] foo
+- [x] bar
+^D
+ - [ ] foo
+ - [x] bar
+```
diff --git a/test/command/tasklist.md b/test/command/tasklist.md
new file mode 100644
index 000000000..5ff628e1c
--- /dev/null
+++ b/test/command/tasklist.md
@@ -0,0 +1,113 @@
+tests adapted from <https://github.github.com/gfm/#task-list-items-extension->
+
+```
+% pandoc
+- [ ] foo
+- [x] bar
+^D
+<ul>
+<li><input type="checkbox" disabled="" />
+foo</li>
+<li><input type="checkbox" disabled="" checked="" />
+bar</li>
+</ul>
+```
+
+
+```
+% pandoc
+- [x] foo
+ - [ ] bar
+ - [x] baz
+- [ ] bim
+^D
+<ul>
+<li><input type="checkbox" disabled="" checked="" />
+foo<ul>
+<li><input type="checkbox" disabled="" />
+bar</li>
+<li><input type="checkbox" disabled="" checked="" />
+baz</li>
+</ul></li>
+<li><input type="checkbox" disabled="" />
+bim</li>
+</ul>
+```
+
+
+custom html task list test:
+
+```
+% pandoc
+- [ ] unchecked
+- plain item
+- [x] checked
+
+paragraph
+
+1. [ ] ordered unchecked
+2. [] plain item
+3. [x] ordered checked
+
+paragraph
+
+- [ ] list item with a
+
+ second paragraph
+
+- [x] checked
+^D
+<ul>
+<li><input type="checkbox" disabled="" />
+unchecked</li>
+<li>plain item</li>
+<li><input type="checkbox" disabled="" checked="" />
+checked</li>
+</ul>
+<p>paragraph</p>
+<ol type="1">
+<li><input type="checkbox" disabled="" />
+ordered unchecked</li>
+<li>[] plain item</li>
+<li><input type="checkbox" disabled="" checked="" />
+ordered checked</li>
+</ol>
+<p>paragraph</p>
+<ul>
+<li><p><input type="checkbox" disabled="" />
+list item with a</p><p>second paragraph</p></li>
+<li><p><input type="checkbox" disabled="" checked="" />
+checked</p></li>
+</ul>
+```
+
+latex task list test:
+
+```
+% pandoc -t latex
+- [ ] foo bar
+
+ baz
+
+- [x] ok
+^D
+\begin{itemize}
+\item[$\square$]
+ foo bar
+
+ baz
+\item[$\boxtimes$]
+ ok
+\end{itemize}
+```
+
+round trip:
+
+```
+% pandoc -f markdown -t markdown
+- [ ] foo
+- [x] bar
+^D
+- [ ] foo
+- [x] bar
+```