Merge pull request #2281 from mbarczak/features/toc_generator

Automatic table of contents generation for Markdown

browser/lib/markdown-toc-generator.js

@@ -0,0 +1,100 @@
+/**
+ * @fileoverview Markdown table of contents generator
+ */
+
+import toc from 'markdown-toc'
+import diacritics from 'diacritics-map'
+import stripColor from 'strip-color'
+
+const EOL = require('os').EOL
+
+/**
+ * @caseSensitiveSlugify Custom slugify function
+ * Same implementation that the original used by markdown-toc (node_modules/markdown-toc/lib/utils.js),
+ * but keeps original case to properly handle https://github.com/BoostIO/Boostnote/issues/2067
+ */
+function caseSensitiveSlugify (str) {
+  function replaceDiacritics (str) {
+    return str.replace(/[À-ž]/g, function (ch) {
+      return diacritics[ch] || ch
+    })
+  }
+
+  function getTitle (str) {
+    if (/^\[[^\]]+\]\(/.test(str)) {
+      var m = /^\[([^\]]+)\]/.exec(str)
+      if (m) return m[1]
+    }
+    return str
+  }
+
+  str = getTitle(str)
+  str = stripColor(str)
+  // str = str.toLowerCase() //let's be case sensitive
+
+  // `.split()` is often (but not always) faster than `.replace()`
+  str = str.split(' ').join('-')
+  str = str.split(/\t/).join('--')
+  str = str.split(/<\/?[^>]+>/).join('')
+  str = str.split(/[|$&`~=\\\/@+*!?({[\]})<>=.,;:'"^]/).join('')
+  str = str.split(/[。？！，、；：“”【】（）〔〕［］﹃﹄“ ”‘’﹁﹂—…－～《》〈〉「」]/).join('')
+  str = replaceDiacritics(str)
+  return str
+}
+
+const TOC_MARKER_START = '<!-- toc -->'
+const TOC_MARKER_END = '<!-- tocstop -->'
+
+/**
+ * Takes care of proper updating given editor with TOC.
+ * If TOC doesn't exit in the editor, it's inserted at current caret position.
+ * Otherwise,TOC is updated in place.
+ * @param editor CodeMirror editor to be updated with TOC
+ */
+export function generateInEditor (editor) {
+  const tocRegex = new RegExp(`${TOC_MARKER_START}[\\s\\S]*?${TOC_MARKER_END}`)
+
+  function tocExistsInEditor () {
+    return tocRegex.test(editor.getValue())
+  }
+
+  function updateExistingToc () {
+    const toc = generate(editor.getValue())
+    const search = editor.getSearchCursor(tocRegex)
+    while (search.findNext()) {
+      search.replace(toc)
+    }
+  }
+
+  function addTocAtCursorPosition () {
+    const toc = generate(editor.getRange(editor.getCursor(), {line: Infinity}))
+    editor.replaceRange(wrapTocWithEol(toc, editor), editor.getCursor())
+  }
+
+  if (tocExistsInEditor()) {
+    updateExistingToc()
+  } else {
+    addTocAtCursorPosition()
+  }
+}
+
+/**
+ * Generates MD TOC based on MD document passed as string.
+ * @param markdownText MD document
+ * @returns generatedTOC String containing generated TOC
+ */
+export function generate (markdownText) {
+  const generatedToc = toc(markdownText, {slugify: caseSensitiveSlugify})
+  return TOC_MARKER_START + EOL + EOL + generatedToc.content + EOL + EOL + TOC_MARKER_END
+}
+
+function wrapTocWithEol (toc, editor) {
+  const leftWrap = editor.getCursor().ch === 0 ? '' : EOL
+  const rightWrap = editor.getLine(editor.getCursor().line).length === editor.getCursor().ch ? '' : EOL
+  return leftWrap + toc + rightWrap
+}
+
+export default {
+  generate,
+  generateInEditor
+}