metalsmith-structure

A Metalsmith plugin that transforms markdown-generated HTML to be hierarchically structured and extracts heading hierarchy for navigation.
Useful for generating a table of contents for your pages, or making your sections collapsible.

Installation

$ npm install --save metalsmith-structure

Example

var Metalsmith = require('metalsmith'),
  markdown = require('metalsmith-markdown'),
  structure = require('metalsmith-structure');

Metalsmith(__dirname)
  .use(markdown())
  .use(structure({
    // All of these options are optional
    headings: ['h1', 'h2', 'h3'],
    divId: '%s-content',
    divAttrs: {
      class: 'generated-div',
      'data-collapse': 'collapse'
    }
  }))
  .build();

Options

metalsmith-structure takes a single options object which supports the following options:

• headings - an array of heading tags to use, you can use this to ignore certain heading levels,
  by default this is set to ['h1', 'h2', 'h3'], meaning that lower-level headings, such as h4 and h5 will be ignored.
  The order of these tags matter as it is used to determine hierarchical level.
• divId - Format for generated div ids, default is %s-content, so heading-1 will produce heading-1-content, %s will be replaced by the heading id.
• divAttrs - Optional object containing additional HTML attributes for generated divs, for example { class: 'collapse' }

Output

metalsmith-structure transforms the generated HTML so it contains divs that group the content based on headings.
For example, starting from the following markdown:

# Heading 1
## Heading 1.1
Content 1.1
# Heading 2
Content 2

The end result will be:

<h1>Heading 1</h1>
<div id="heading-1-content">
  <h2 id="heading-1-1">Heading 1.1</h2>
  <div id="heading-1-1-content">
    Content 1.1
  </div>
</div>
<h1 id="heading-2">Heading 2</h1>
<div id="heading-2-content">
  Content 2
</div>

metalsmith-structure also adds a headings array to the metadata, which can be used to render navigation.

For the above document, the headings array will look like this:

[
  {
    id: 'heading-1', //original id of the heading generated by markdown, this is moved to the generated div
    priority: 0, //lower number means higher priority
    tag: 'h1',
    text: 'Heading 1', 
    children: [
      {
        id: 'heading-1-1',
        priority: 1,
        tag: 'h2',
        text: 'Heading 1.1'
      }
    ]
  },
  {
    id: 'heading-2',
    priority: 0,
    tag: 'h1',
    text: 'Heading 2'
  }
]

License

This project uses the MIT License, see LICENSE for more information.