Automatically inserts a TOC to HTML files generated from markdown

README.md

mdTOC

If inserted in a HTML document auto-generated from markdown a TOC sidebar gets generated automatically.

How to use it with MarkdownPad

MarkdownPad is a Markdown Editor for Windows.

1. Use the included stylesheet in this Gist. Replace an old one or create a new one.
   • Tools → Options → Stylesheets → Add or Edit
   • replace stylesheet completely.
2. Include the JavaScript in the HTML head.
   • Tools → Options → Advanced → HTML Head Editor
   • Paste the script and add <script> at the beginning and </script> at the end of the script. The script must be between those two tags.

And you're done. Have fun :)

markdownpad-github-plus-toc.css

/* GitHub stylesheet for MarkdownPad (http://markdownpad.com) */
/* Author: Nicolas Hery - http://nicolashery.com */
/* Version: b13fe65ca28d2e568c6ed5d7f06581183df8f2ff */
/* Source: https://github.com/nicolahery/markdownpad-github */

/* RESET
=============================================================================*/

html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video {
  margin: 0;
  padding: 0;
  border: 0;
}

/* TOC
=============================================================================*/

#toc {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 25vw;
  overflow: auto;
  border-right: 1px solid #cccccc;
}

#toc > div {
  border-bottom: 1px solid #cccccc;
}

#toc > div a {
  display: block;
  padding: 5px 15px;
  color: #333;
}

#toc > .level-1 {
  font-weight: normal;
  font-size: 20px;
  background: #333;
}
#toc > .level-1 a {
  color: #ddd;
  padding-top: 20px;
}

#toc > .level-2 {
  font-weight: bold;
  background: #e5e5e5;
}

#toc > .level-3 {
  padding-left: 15px;
  background: #f5f5f5;
}

#toc > .level-4 {
  padding-left: 30px;
}

#toc > .level-5 {
  padding-left: 45px;
}
#toc > .level-5 a {
  color: #666;
}

#toc > .level-6	 {
  padding-left: 60px;
}
#toc > .level-6 a {
  color: #777;
}

/* BODY
=============================================================================*/

body {
  font-family: "Calibri", Helvetica, arial, freesans, clean, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: #333;
  background-color: #fff;
  padding: 20px;
  max-width: 650px;
  margin: 0 auto
}

body.toc-loaded {
  max-width: initial;
  margin: 0 0 0 25vw;
}

main {
  display: block;
  max-width: 650px;
  margin: 0 auto;
}

body>*:first-child {
  margin-top: 0 !important;
}

body>*:last-child {
  margin-bottom: 0 !important;
}

/* BLOCKS
=============================================================================*/

p, blockquote, ul, ol, dl, table, pre {
  margin: 15px 0;
}

/* HEADERS
=============================================================================*/

h1, h2, h3, h4, h5, h6 {
  margin: 20px 0 10px;
  padding: 0;
  font-weight: bold;
  -webkit-font-smoothing: antialiased;
}

h1 tt, h1 code, h2 tt, h2 code, h3 tt, h3 code, h4 tt, h4 code, h5 tt, h5 code, h6 tt, h6 code {
  font-size: inherit;
}

h1 {
  font-size: 28px;
  color: #000;
}

h2 {
  font-size: 24px;
  border-bottom: 1px solid #ccc;
  color: #000;
}

h3 {
  font-size: 18px;
}

h4 {
  font-size: 16px;
}

h5 {
  font-size: 14px;
}

h6 {
  color: #777;
  font-size: 14px;
}

body>h2:first-child, body>h1:first-child, body>h1:first-child+h2, body>h3:first-child, body>h4:first-child, body>h5:first-child, body>h6:first-child {
  margin-top: 0;
  padding-top: 0;
}

a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
  margin-top: 0;
  padding-top: 0;
}

h1+p, h2+p, h3+p, h4+p, h5+p, h6+p {
  margin-top: 10px;
}

/* LINKS
=============================================================================*/

a {
  color: #4183C4;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* LISTS
=============================================================================*/

ul, ol {
  padding-left: 30px;
}

ul li > :first-child, 
ol li > :first-child, 
ul li ul:first-of-type, 
ol li ol:first-of-type, 
ul li ol:first-of-type, 
ol li ul:first-of-type {
  margin-top: 0px;
}

ul ul, ul ol, ol ol, ol ul {
  margin-bottom: 0;
}

dl {
  padding: 0;
}

dl dt {
  font-size: 14px;
  font-weight: bold;
  font-style: italic;
  padding: 0;
  margin: 15px 0 5px;
}

dl dt:first-child {
  padding: 0;
}

dl dt>:first-child {
  margin-top: 0px;
}

dl dt>:last-child {
  margin-bottom: 0px;
}

dl dd {
  margin: 0 0 15px;
  padding: 0 15px;
}

dl dd>:first-child {
  margin-top: 0px;
}

dl dd>:last-child {
  margin-bottom: 0px;
}

/* CODE
=============================================================================*/

pre, code, tt {
  font-size: 12px;
  font-family: Consolas, "Liberation Mono", Courier, monospace;
}

code, tt {
  margin: 0 0px;
  padding: 0px 0px;
  white-space: nowrap;
  border: 1px solid #eaeaea;
  background-color: #f8f8f8;
  border-radius: 3px;
}

pre>code {
  margin: 0;
  padding: 0;
  white-space: pre;
  border: none;
  background: transparent;
}

pre {
  background-color: #f8f8f8;
  border: 1px solid #ccc;
  font-size: 13px;
  line-height: 19px;
  overflow: auto;
  padding: 6px 10px;
  border-radius: 3px;
}

pre code, pre tt {
  background-color: transparent;
  border: none;
}

kbd {
    -moz-border-bottom-colors: none;
    -moz-border-left-colors: none;
    -moz-border-right-colors: none;
    -moz-border-top-colors: none;
    background-color: #DDDDDD;
    background-image: linear-gradient(#F1F1F1, #DDDDDD);
    background-repeat: repeat-x;
    border-color: #DDDDDD #CCCCCC #CCCCCC #DDDDDD;
    border-image: none;
    border-radius: 2px 2px 2px 2px;
    border-style: solid;
    border-width: 1px;
    font-family: "Helvetica Neue",Helvetica,Arial,sans-serif;
    line-height: 10px;
    padding: 1px 4px;
}

/* QUOTES
=============================================================================*/

blockquote {
  border-left: 4px solid #DDD;
  padding: 0 15px;
  color: #777;
}

blockquote>:first-child {
  margin-top: 0px;
}

blockquote>:last-child {
  margin-bottom: 0px;
}

/* HORIZONTAL RULES
=============================================================================*/

hr {
  clear: both;
  margin: 15px 0;
  height: 0px;
  overflow: hidden;
  border: none;
  background: transparent;
  border-bottom: 4px solid #ddd;
  padding: 0;
}

/* TABLES
=============================================================================*/

table {
  width: 100%;
  border-spacing: 0;
  border-collapse: collapse;
}

table th {
  font-weight: bold;
}

table th, table td {
  border: 1px solid #ccc;
  padding: 6px 13px;
}

table tr {
  border-top: 1px solid #ccc;
  background-color: #fff;
}

table tr:nth-child(2n) {
  background-color: #f8f8f8;
}

/* IMAGES
=============================================================================*/

img {
  max-width: 100%
}

md-toc.js

'use strict';

function addTOC() {
    var tocElement, bodyContent, mainElement;

    tocElement = document.createElement('nav');
    tocElement.setAttribute('id', 'toc');

    bodyContent = document.body.innerHTML;

    mainElement = document.createElement('main');
    mainElement.insertAdjacentHTML('afterbegin', bodyContent);

    generateTOC(tocElement, mainElement);

    document.body.innerHTML = '';
    document.body.insertAdjacentHTML('afterbegin', tocElement.outerHTML);
    document.body.insertAdjacentHTML('beforeend', mainElement.outerHTML);
    document.body.classList.add('toc-loaded');

    // FUNCTIONS

    function generateTOC(tocElement, mainElement) {
        var headlineElements, currentElement, currentHeadlineElement, currentHeadlineLinkElement, i;

        headlineElements = mainElement.querySelectorAll('h1, h2, h3, h4, h5, h6');

        for (i = 0; i < headlineElements.length; i++) {
            currentElement = headlineElements[i];
            currentElement.setAttribute('id', i);

            currentHeadlineLinkElement = document.createElement('a');
            currentHeadlineLinkElement.setAttribute('href', '#' + i);
            currentHeadlineLinkElement.innerHTML = currentElement.innerHTML;

            currentHeadlineElement = document.createElement('div');
            currentHeadlineElement.classList.add(currentElement.tagName.replace('H', 'level-'));
            currentHeadlineElement.insertAdjacentHTML('afterbegin', currentHeadlineLinkElement.outerHTML);

            tocElement.insertAdjacentHTML('beforeend', currentHeadlineElement.outerHTML);
        }
    }
}

document.addEventListener('DOMContentLoaded', addTOC, false);