GitBook plugin: InTopic TOC

This GitBook plugin adds an inline table of contents (TOC) to each page based on configurable selectors. Inline TOC can be enabled or disabled by default or on individual pages. TOC is placed on the right side and moves to top for smaller devices automatically.

Inline TOC stays at the top of the page when scrolling using a sticky effect. Current position is highlighted by a scrollspy effect.

Plugin uses gumshoe and anchorjs to implement functionality.

Installation

Step #1 - Update book.json file

In you gitbook's book.json file, add intopic-toc to plugins list.
In pluginsConfig, configure the plugin so it does fit your needs. A custom setup is not mandatory.

Sample book.json file for gitbook version 2.0.0+

{
  "plugins": [
    "intopic-toc"
  ]
}

Sample book.json file for gitbook version 2.0.0+ and custom heading

{
  "plugins": [
    "intopic-toc"
  ],
  "pluginsConfig": {
    "intopic-toc": {
      "label": "In this article"
    }
  }
}

Sample book.json file for gitbook version 2.0.0+ and multilingual headings

{
  "plugins": [
    "intopic-toc"
  ],
  "pluginsConfig": {
    "intopic-toc": {
      "label": {
        "de": "In diesem Artikel",
        "en": "In this article"
      }
    }
  }
}

Note: Above snippets can be used as complete book.json file, if one of these matches your requirements and your book doesn't have one yet.

Step #2 - gitbook commands

Run gitbook install. It will automatically install intopic-toc gitbook plugin for your book. This is needed only once.
Build your book (gitbook build) or serve (gitbook serve) as usual.

Usage

For basic usage, the only thing you have to do is install the plugin. For advanced scenarios see following configuration sample.

{
  "plugins": [
    "intopic-toc"
  ],
  "pluginsConfig": {
    "intopic-toc": {
      "selector": ".markdown-section h1, .markdown-section h2, .markdown-section h3, .markdown-section h4, .markdown-section h5, .markdown-section h6",
      "mode": "nested",
      "maxDepth": 2,
      "isCollapsed": false,
      "isScrollspyActive": true,
      "visible": true,
      "label": {
        "de": "In diesem Artikel",
        "en": "In this article"
      },
    }
  }
}

Property	Description	Default value
selector	Selector used to find elements to put anchors on - only HTML headings h1 - h6 are allowed.	.markdown-section h1, .markdown-section h2, .markdown-section h3, .markdown-section h4, .markdown-section h5, .markdown-section h6
mode	Defines how plugin will be rendered. Possible values: 'flat' or 'nested'.	nested
maxDepth	Defines the amount of headings which should be considered during rendering.	6
isCollapsed	Defines whether the items are collapsed by default and are only expanded when activated. (Only considered when mode = 'nested')	true
isScrollspyActive	Defines whether scrollspy effect should be applied.	true
visible	Defines whether to show the navigation on every page	true
label	Label which is used as heading for the navigation. Could be a single string or an object for multilingual setups	In this article

Visibility

If visible parameter set to true and you want to hide the TOC on a single page, add the front matter item isTocVisible: false to the top of the Markdown file like this:

---
isTocVisible: false
---
# My awesome documentation

Lorem ipsum dolor sit amet, consetetur sadipscing elitr, ...

The specific front matter isTocVisible overrides the visible parameter from global configuration.

Headings

Heading are identified using selector property of the plugin. Usually there is no need to adjust the default value. For customizations see following sections.

By default, the plugin chooses the top-level navigation items by searching for headings at the first identified heading level using selector property value, then works its way down (<h1/>, then <h2/>, etc.) It will stop when it finds the first set of headings where more than one exists at that level. For example (assuming we do not have modified the selector property):

<h1>Title</h1>
...
<h2>1 Section 1</h2>
<h3>1.1 Subsection</h3>
...
<h4>1.1.1 Subsection</h4>
...
<h3>1.2 Subsection</h3>
...
<h2>2 Section 2</h2>
<h3>2.1 Subsection</h3>
...

The plugin would see there’s only one <h1>, then that <h2> appears two times. Then it stops and identified level becomes the top-level navigation items in the table of contents. Following headings under those (the <h3>s and <h4>s in this case) would be the next levels in the navigation.

Described mechanism applies to all flat and nested mode. Rendering depth could be limited by specifying maxDepth property value.

Resulting table of contents using mode = flat and maxDepth = 2 would look like:

1 Section 1
1.1 Subsection
1.2 Subsection
2 Section 2
2.1 Subsection

Resulting table of contents using mode = nested and maxDepth = 2 would look like:

1 Section 1
  1.1 Subsection
  1.2 Subsection
2 Section 2
  2.1 Subsection

Troubleshooting

If inline TOC does not look as expected, check if your book.json is valid according to this documentation.

Changelog

08/20/2022

Updated development dependencies and moved to GitHub Actions
Updated anchorjs dependency to version 4.3.1

05/03/2020

Added support for different layout modes along with improved scrollspy experience

01/07/2019

Used gumshoe scrollspy script for a better experience

01/05/2019

Initial Release

fzankl / gitbook-plugin-intopic-toc