GFM checkbox

browser/lib/markdown.js

@@ -61,7 +61,58 @@ md.use(math, {
   }
 })
 md.use(require('markdown-it-footnote'))
+// Override task item
+md.block.ruler.at('paragraph', function (state, startLine/*, endLine*/) {
+  let content, terminate, i, l, token
+  let nextLine = startLine + 1
+  let terminatorRules = state.md.block.ruler.getRules('paragraph')
+  let endLine = state.lineMax
 
+  // jump line-by-line until empty one or EOF
+  for (; nextLine < endLine && !state.isEmpty(nextLine); nextLine++) {
+    // this would be a code block normally, but after paragraph
+    // it's considered a lazy continuation regardless of what's there
+    if (state.sCount[nextLine] - state.blkIndent > 3) { continue }
+
+    // quirk for blockquotes, this line should already be checked by that rule
+    if (state.sCount[nextLine] < 0) { continue }
+
+    // Some tags can terminate paragraph without empty line.
+    terminate = false
+    for (i = 0, l = terminatorRules.length; i < l; i++) {
+      if (terminatorRules[i](state, nextLine, endLine, true)) {
+        terminate = true
+        break
+      }
+    }
+    if (terminate) { break }
+  }
+
+  content = state.getLines(startLine, nextLine, state.blkIndent, false).trim()
+
+  state.line = nextLine
+
+  token = state.push('paragraph_open', 'p', 1)
+  token.map = [ startLine, state.line ]
+
+  if (state.parentType === 'list') {
+    let match = content.match(/\[( |x)\] ?(.+)/i)
+    if (match) {
+      content = `<label class='taskListItem' for='checkbox-${startLine + 1}'><input type='checkbox'${match[1] !== ' ' ? ' checked' : ''} id='checkbox-${startLine + 1}'/> ${match[2]}</label>`
+    }
+  }
+
+  token = state.push('inline', '', 0)
+  token.content = content
+  token.map = [ startLine, state.line ]
+  token.children = []
+
+  token = state.push('paragraph_close', 'p', -1)
+
+  return true
+})
+
+// Add line number attribute for scrolling
 let originalRender = md.renderer.render
 md.renderer.render = function render (tokens, options, env) {
   tokens.forEach((token) => {