Uttori Renderer - Markdown - MarkdownIt

Uttori renderer support for Markdown powered by MarkdownIt.

This also includes a MarkdownIt plugin you can use seperately that supports:

• Generate a Table of Contents based on H# header tags with [toc]
• Adding a URL prefix
• Properly handle external domains with noopener noreferrer and optionally set up allowed domains for nofollow SEO support to curb spam
• Support for [^1] ... [^1]: Footnote Footnotes based on markdown-it-footnote
• Support for WikiLinks style linking
• Support for adding Lazy Loading tags to img tags
• Support for adding YouTube iframe videos
• Support for <br> or <br/> or <br /> style line breaks anywhere, useful for tables
• Support for <video src="/uploads/example.mp4"> video embeds with allowed domains filtering
• Support for adding color to spans with [Text](color:#ffadad)
• Parse to tokens for building an AST (abstract syntax tree) using MarkdownItRenderer.parse(content, config)

Install

npm install --save @uttori/plugin-renderer-markdown-it

Config

Configuration outside of registration events and Uttori specific items is avaliable by passing in MarkdownIt config.

{
  // Registration Events
  events: {
    renderContent: [],
    renderCollection: [],
    validateConfig: [],
    viewModelDetail: [],
  },

  // MarkdownIt Configuration
  // Enable HTML tags in source
  html: false,

  // Use '/' to close single tags (<br />).
  xhtmlOut: false,

  // Convert '\n' in paragraphs into <br>, this is only for full CommonMark compatibility.
  breaks: false,

  // CSS language prefix for fenced blocks. Can be useful for external highlighters.
  langPrefix: 'language-',

  // Autoconvert URL-like text to links.
  linkify: false,

  // Enable some language-neutral replacement + quotes beautification.
  typographer: false,

  // Double + single quotes replacement pairs, when typographer enabled, and smartquotes on. Could be either a String or an Array.
  // For example, you can use '«»„“' for Russian, '„“‚‘' for German, and ['«\xA0', '\xA0»', '‹\xA0', '\xA0›'] for French (including nbsp).
  quotes: '“”‘’',

  // Highlighter function. Should return escaped HTML, or '' if the source string is not changed and should be escaped externally.
  // If result starts with <pre... internal wrapper is skipped.
  // highlight: (/* str, lang */) => '',

  // Any other supported MarkdownIt configuration
  ...,

  // Custom Values for Uttori Specific Use
  uttori: {
    // Prefix for relative URLs, useful when the Express app is not at root.
    baseUrl: '',

    // Good Noodle List, f a domain is not in this list, it is set to 'external nofollow noreferrer'.
    allowedExternalDomains: [],

    // Open external domains in a new window.
    openNewWindow: true,

    // Add lazy loading params to image tags.
    lazyImages: true,

    // Footnotes
    footnotes: {
      // A funciton to return the default HTML for a footnote reference.
      referenceTag: ({ id, label }) => {
        return `...`;
      },

      // A funciton to return the default opening HTML for a footnote definition.
      definitionOpenTag: ({ id, label }) => {
        return `...`;
      },

      // The default closing HTML for a footnote definition.
      definitionCloseTag: '</div>\n',
    },

    // Table of Contents
    toc: {
      // The opening DOM tag for the TOC container.
      openingTag: '<nav class="table-of-contents">',

      // The closing DOM tag for the TOC container.
      closingTag: '</nav>',

      // Slugify options for convering headings to anchor links.
      slugify: {
        lower: true,
      },
    },

    // WikiLinks
    wikilinks: {
      // Slugify options for convering Wikilinks to anchor links.
      slugify: {
        lower: true,
      },
    },
  },
}

Table of Contents Generation

You can generate a table of contents based on the headers in a file. Example:

# First
## Second
### Third
### Third Again
#### Fouth

## Second Again
### Third Last
Content

[toc]

Will render to a minified version of:

<p>
  <nav class="table-of-contents">
    <ul class="table-of-contents-h1">
      <li><a href="#first-0" title="First">First</a></li>
      <li><ul class="table-of-contents-h2">
        <li><a href="#second-1" title="Second">Second</a></li>
        <li><ul class="table-of-contents-h3">
          <li><a href="#third-2" title="Third">Third</a></li>
          <li><a href="#third-again-3" title="Third Again">Third Again</a></li>
          <li><ul class="table-of-contents-h4">
            <li><a href="#fouth-4" title="Fouth">Fouth</a></li>
          </ul></li>
        </ul></li>
        <li><a href="#second-again-6" title="Second Again">Second Again</a></li>
        <li><ul class="table-of-contents-h3">
          <li><a href="#third-last-7" title="Third Last">Third Last</a></li>
        </ul></li>
      </ul></li>
    </ul>
  </nav>
  Content Content
</p>

Footnotes

This allos for adding footnotes & their definitions.

`ADC (dp,X)`[^1]

[^1]: Add 1 cycle if m=0 (16-bit memory/accumulator)

YouTube Embedding

This allows safe embedding of YouTube videos. Example:

<youtube v="XG9dCoTlJYA" start="0" width="560" height="315" title="YouTube Video Player" start="0">

Will render to a minified version of:

<div class="youtube-embed">
  <iframe class="youtube-embed-video" width="560" height="315" src="https://www.youtube-nocookie.com/embed/aR3fVuLEtj8?start=0" title="YouTube Video Player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="true"></iframe>
</div>

The only required parameter is v:

<youtube v="aR3fVuLEtj8">

Will render to a minified version of:

<div class="youtube-embed">
  <iframe class="youtube-embed-video" width="560" height="315" src="https://www.youtube-nocookie.com/embed/aR3fVuLEtj8?start=0" title="" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="true"></iframe>
</div>

Colored Text

You can add colored text with special links:

[Text](color:#ffadad)
[Text](color:#ffd6a5)
[Text](color:#fdffb6)
[Text](color:#caffbf)
[Text](color:#9bf6ff)
[Text](color:#A0C4FF)
[Text](color:#bdb2ff)
[Text](color:#ffcff8)
[Text](color:#fffffc)
[Text](color:rgba(0,0,0,0.5))

---

API Reference

Classes

MarkdownItRenderer

Uttori MarkdownIt Renderer

Typedefs

MarkdownItRendererOptions : object

MarkdownItRenderer

Uttori MarkdownIt Renderer

Kind: global class

• MarkdownItRenderer
  • .configKey ⇒ string
  • .defaultConfig() ⇒ MarkdownItRendererOptions
  • .extendConfig(config) ⇒ MarkdownItRendererOptions
  • .validateConfig(config, _context)
  • .register(context)
  • .renderContent(content, context) ⇒ string
  • .renderCollection(collection, context) ⇒ Array.<object>
  • .render(content, [config]) ⇒ string
  • .parse(content, [config]) ⇒ Array.<module:markdown-it/lib/token>
  • .cleanContent(content) ⇒ string
  • .viewModelDetail(viewModel, context) ⇒ object

MarkdownItRenderer.configKey ⇒ string

The configuration key for plugin to look for in the provided configuration.

Kind: static property of MarkdownItRenderer
Returns: string - The configuration key.
Example (MarkdownItRenderer.configKey)

const config = { ...MarkdownItRenderer.defaultConfig(), ...context.config[MarkdownItRenderer.configKey] };

MarkdownItRenderer.defaultConfig() ⇒ MarkdownItRendererOptions

The default configuration.

Kind: static method of MarkdownItRenderer
Returns: MarkdownItRendererOptions - The default configuration.
Example (MarkdownItRenderer.defaultConfig())

const config = { ...MarkdownItRenderer.defaultConfig(), ...context.config[MarkdownItRenderer.configKey] };

MarkdownItRenderer.extendConfig(config) ⇒ MarkdownItRendererOptions

Create a config that is extended from the default config.

Kind: static method of MarkdownItRenderer
Returns: MarkdownItRendererOptions - The new configration.

Param	Type	Description
config	MarkdownItRendererOptions	The user provided configuration.

MarkdownItRenderer.validateConfig(config, _context)

Validates the provided configuration for required entries.

Kind: static method of MarkdownItRenderer

Param	Type	Description
config	Record.<string, MarkdownItRendererOptions>	A provided configuration to use.
_context	object	Unused

Example (MarkdownItRenderer.validateConfig(config, _context))

MarkdownItRenderer.validateConfig({ ... });

MarkdownItRenderer.register(context)

Register the plugin with a provided set of events on a provided Hook system.

Kind: static method of MarkdownItRenderer

Param	Type	Description
context	object	A Uttori-like context.
context.hooks	object	An event system / hook system to use.
context.hooks.on	function	An event registration function.
context.config	MarkdownItRendererOptions	A provided configuration to use.

Example (MarkdownItRenderer.register(context))

const context = {
  hooks: {
    on: (event, callback) => { ... },
  },
  config: {
    [MarkdownItRenderer.configKey]: {
      ...,
      events: {
        renderContent: ['render-content', 'render-meta-description'],
        renderCollection: ['render-search-results'],
        validateConfig: ['validate-config'],
      },
    },
  },
};
MarkdownItRenderer.register(context);

MarkdownItRenderer.renderContent(content, context) ⇒ string

Renders Markdown for a provided string with a provided context.

Kind: static method of MarkdownItRenderer
Returns: string - The rendered content.

Param	Type	Description
content	string	Markdown content to be converted to HTML.
context	object	A Uttori-like context.
context.config	MarkdownItRendererOptions	A provided configuration to use.

Example (MarkdownItRenderer.renderContent(content, context))

const context = {
  config: {
    [MarkdownItRenderer.configKey]: {
      ...,
    },
  },
};
MarkdownItRenderer.renderContent(content, context);

MarkdownItRenderer.renderCollection(collection, context) ⇒ Array.<object>

Renders Markdown for a collection of Uttori documents with a provided context.

Kind: static method of MarkdownItRenderer
Returns: Array.<object> - } The rendered documents.

Param	Type	Description
collection	Array.<object>	A collection of Uttori documents.
context	object	A Uttori-like context.
context.config	MarkdownItRendererOptions	A provided MarkdownIt configuration to use.

Example (MarkdownItRenderer.renderCollection(collection, context))

const context = {
  config: {
    [MarkdownItRenderer.configKey]: {
      ...,
    },
  },
};
MarkdownItRenderer.renderCollection(collection, context);

MarkdownItRenderer.render(content, [config]) ⇒ string

Renders Markdown for a provided string with a provided MarkdownIt configuration.

Kind: static method of MarkdownItRenderer
Returns: string - The rendered content.

Param	Type	Description
content	string	Markdown content to be converted to HTML.
[config]	MarkdownItRendererOptions	A provided MarkdownIt configuration to use.

Example (MarkdownItRenderer.render(content, config))

const html = MarkdownItRenderer.render(content, config);

MarkdownItRenderer.parse(content, [config]) ⇒ Array.<module:markdown-it/lib/token>

Parse Markdown for a provided string with a provided MarkdownIt configuration.

Kind: static method of MarkdownItRenderer
Returns: Array.<module:markdown-it/lib/token> - The rendered content.
See: MarkdownIt.parse

Param	Type	Description
content	string	Markdown content to be converted to HTML.
[config]	MarkdownItRendererOptions	A provided MarkdownIt configuration to use.

Example (MarkdownItRenderer.parse(content, config))

const tokens = MarkdownItRenderer.parse(content, config);

MarkdownItRenderer.cleanContent(content) ⇒ string

Removes empty links, as these have caused issues. Find missing links, and link them to the slug from the provided text.

Kind: static method of MarkdownItRenderer
Returns: string - The rendered content.

Param	Type	Description
content	string	Markdown content to be converted to HTML.

MarkdownItRenderer.viewModelDetail(viewModel, context) ⇒ object

Will attempt to extract the table of contents when set to and add it to the view model.

Kind: static method of MarkdownItRenderer
Returns: object - The view model.

Param	Type	Description
viewModel	object	Markdown content to be converted to HTML.
context	object	A Uttori-like context.
context.config	MarkdownItRendererOptions	A provided configuration to use.

Example (MarkdownItRenderer.viewModelDetail(viewModel, context))

viewModel = MarkdownItRenderer.viewModelDetail(viewModel, context);

MarkdownItRendererOptions : object

Kind: global typedef
Properties

Name	Type	Description
baseUrl	string	Prefix for relative URLs, useful when the Express app is not at URI root.
allowedExternalDomains	Array.<string>	Allowed External Domains, if a domain is not in this list, it is set to 'nofollow'. Values should be strings of the hostname portion of the URL object (like example.org).
disableValidation	boolean	Optionally disable the built in Markdown-It link validation, large security risks when link validation is disabled.
openNewWindow	boolean	Open external domains in a new window.
lazyImages	boolean	Add lazy loading params to image tags.
footnotes	object	Footnote settings.
footnotes.referenceTag	function	A funciton to return the default HTML for a footnote reference.
footnotes.definitionOpenTag	function	A funciton to return the default opening HTML for a footnote definition.
footnotes.definitionCloseTag	string	The default closing HTML for a footnote definition.
toc	object	Table of Contents settings.
toc.extract	boolean	When true, extract the table of contents to the view model from the content.
toc.openingTag	string	The opening DOM tag for the TOC container.
toc.closingTag	string	The closing DOM tag for the TOC container.
toc.slugify	object	Slugify options for convering headings to anchor links.
wikilinks	object	WikiLinks settings.
wikilinks.slugify	object	Slugify options for convering Wikilinks to anchor links.

---

Tests

To run the test suite, first install the dependencies, then run npm test:

npm install
npm test
DEBUG=Uttori* npm test

Contributors

• Matthew Callis

License

• MIT