[

Markdownify TS

A TypeScript port of python-markdownify - Convert HTML to Markdown.

Installation

npm install @wqyjh/markdownify

Usage

TypeScript / ES Modules (ESM)

import { markdownify } from '@wqyjh/markdownify';
const result = markdownify('<b>Yay</b> <a href="http://github.com">GitHub</a>');

CommonJS (CJS)

const { markdownify } = require('@wqyjh/markdownify');
const result = markdownify('<b>Yay</b> <a href="http://github.com">GitHub</a>');

Browser (CDN)

<script src="https://cdn.jsdelivr.net/npm/@wqyjh/[email protected]/dist/browser/markdownify.min.js"></script>
<script>
  const { markdownify } = window.Markdownify;
  const result = markdownify('<b>Yay</b> <a href="http://github.com">GitHub</a>');
</script>

Options

Markdownify supports the following options:

strip A list of tags to strip. This option can't be used with the convert option.

convert A list of tags to convert. This option can't be used with the strip option.

autolinks A boolean indicating whether the "automatic link" style should be used when a a tag's contents match its href. Defaults to true.

default_title A boolean to enable setting the title of a link to its href, if no title is given. Defaults to false.

heading_style Defines how headings should be converted. Accepted values are 'atx', 'atx_closed', 'setext', and 'underlined' (which is an alias for 'setext'). You can also use the constants ATX, ATX_CLOSED, SETEXT, and UNDERLINED imported from @wqyjh/markdownify. All option values are case-insensitive (e.g., 'atx', 'ATX', 'Atx' all work). Defaults to 'underlined'.

bullets An iterable (string, list, or tuple) of bullet styles to be used. If the iterable only contains one item, it will be used regardless of how deeply lists are nested. Otherwise, the bullet will alternate based on nesting level. Defaults to '*+-'.

strong_em_symbol In markdown, both * and _ are used to encode strong or emphasized texts. Either of these symbols can be chosen by the options '*' (default) or '_' respectively. You can also use the constants ASTERISK or UNDERSCORE imported from @wqyjh/markdownify. All option values are case-insensitive (e.g., 'asterisk', 'ASTERISK', 'Asterisk' all work).

sub_symbol, sup_symbol Define the chars that surround <sub> and <sup> text. Defaults to an empty string, because this is non-standard behavior. Could be something like ~ and ^ to result in ~sub~ and ^sup^. If the value starts with < and ends with >, it is treated as an HTML tag and a / is inserted after the < in the string used after the text; this allows specifying <sub> to use raw HTML in the output for subscripts, for example.

newline_style Defines the style of marking linebreaks (<br>) in markdown. The default value 'spaces' will adopt the usual two spaces and a newline, while 'backslash' will convert a linebreak to \n (a backslash and a newline). You can also use the constants SPACES or BACKSLASH imported from @wqyjh/markdownify. All option values are case-insensitive (e.g., 'spaces', 'SPACES', 'Spaces' all work). While the latter convention is non-standard, it is commonly preferred and supported by a lot of interpreters.

code_language Defines the language that should be assumed for all <pre> sections. Useful, if all code on a page is in the same programming language and should be annotated with ```python or similar. Defaults to '' (empty string) and can be any string.

code_language_callback When the HTML code contains <pre> tags that in some way provide the code language, for example as class, this callback can be used to extract the language from the tag and prefix it to the converted <pre> tag. The callback gets one single argument, a HTMLElement object, and returns a string containing the code language, or null. An example to use the class name as code language could be:

const options = {
  code_language_callback: (el) => el.getAttribute('class')?.split(' ')[0] || null
};

escape_asterisks If set to false, do not escape * to \* in text. Defaults to true.

escape_underscores If set to false, do not escape _ to \_ in text. Defaults to true.

escape_misc If set to true, escape miscellaneous punctuation characters that sometimes have Markdown significance in text. Defaults to false.

keep_inline_images_in Images are converted to their alt-text when the images are located inside headlines or table cells. If some inline images should be converted to markdown images instead, this option can be set to a list of parent tags that should be allowed to contain inline images, for example ['td']. Defaults to an empty list.

table_infer_header Controls handling of tables with no header row (as indicated by <thead> or <th>). When set to true, the first body row is used as the header row. Defaults to false, which leaves the header row empty.

wrap, wrap_width If wrap is set to true, all text paragraphs are wrapped at wrap_width characters. Defaults to false and 80. Use with newline_style=BACKSLASH to keep line breaks in paragraphs. A wrap_width value of null reflows lines to unlimited line length.

strip_document Controls whether leading and/or trailing separation newlines are removed from the final converted document. Supported values are 'lstrip' (leading), 'rstrip' (trailing), 'strip' (both), and null (neither). You can also use the constants LSTRIP, RSTRIP, and STRIP imported from @wqyjh/markdownify. All option values are case-insensitive (e.g., 'strip', 'STRIP', 'Strip' all work). Newlines within the document are unaffected. Defaults to 'strip'.

strip_pre Controls whether leading/trailing blank lines are removed from <pre> tags. Supported values are 'strip' (all leading/trailing blank lines), 'strip_one' (one leading/trailing blank line), and null (neither). You can also use the constants STRIP and STRIP_ONE imported from @wqyjh/markdownify. All option values are case-insensitive (e.g., 'strip', 'STRIP', 'Strip' all work). Defaults to 'strip'.

Creating Custom Converters

If you have a special usecase that calls for a special conversion, you can always inherit from MarkdownConverter and override the method you want to change. The function that handles a HTML tag named abc is called convert_abc(el, text, parent_tags) and returns a string containing the converted HTML tag. The MarkdownConverter object will handle the conversion based on the function names:

import { MarkdownConverter } from '@wqyjh/markdownify';

class ImageBlockConverter extends MarkdownConverter {
  /**
   * Create a custom MarkdownConverter that adds two newlines after an image
   */
  convert_img(el: HTMLElement, text: string, parent_tags: Set<string>): string {
    return super.convert_img(el, text, parent_tags) + '\n\n';
  }
}

// Create shorthand method for conversion
function md(html: string, options = {}) {
  return new ImageBlockConverter(options).convert(html);
}

import { MarkdownConverter } from '@wqyjh/markdownify';

class IgnoreParagraphsConverter extends MarkdownConverter {
  /**
   * Create a custom MarkdownConverter that ignores paragraphs
   */
  convert_p(el: HTMLElement, text: string, parent_tags: Set<string>): string {
    return '';
  }
}

// Create shorthand method for conversion
function md(html: string, options = {}) {
  return new IgnoreParagraphsConverter(options).convert(html);
}

Development

To run tests and the linter:

npm install
npm test
npm run lint
npm run build

License

MIT