MultiMarkdown table syntax plugin for markdown-it markdown parser

Intro

Markdown specs defines only the basics for tables. When users want common
features like colspan, they must fallback to raw HTML. And writing tables in
HTML is truly lengthy and troublesome.

This plugin extends markdown-it with MultiMarkdown table syntax.
MultiMarkdown is an extended Markdown spec. It defines clear rules for
advanced Markdown table syntax, while being consistent with original pipe
table; markdown-it is a popular Markdown parser in JavaScript and
allows plugins extending itself.

The features are provided:

• Cell spans over columns
• Cell spans over rows (optional)
• Divide rows into sections
• Multiple table headers
• Table caption
• Block-level elements such as lists, codes... (optional)
• Omitted table header (optional)

Noted that the plugin is not a re-written of MultiMarkdown. This plugin will
behave differently from the official compiler, but doing its best to obey rules
defined in MultiMarkdown User's Guide. Please pose an issue if
there are weird results for sensible inputs.

Usage

 // defaults
var md = require('markdown-it')()
            .use(require('markdown-it-multimd-table'));

// full options list (equivalent to defaults)
var md = require('markdown-it')()
            .use(require('markdown-it-multimd-table'), {
              multiline:  false,
              rowspan:    false,
              headerless: false,
              multibody:  true,
              aotolabel:  true,
            });

md.render(/*...*/)

For a quick demo:

 $ mkdir markdown-it-multimd-table
$ cd markdown-it-multimd-table
$ npm install markdown-it markdown-it-multimd-table --prefix .
$ vim test.js

    var md = require('markdown-it')()
                .use(require('markdown-it-multimd-table'));

    const exampleTable =
    "|             |          Grouping           || \n" +
    "First Header  | Second Header | Third Header | \n" +
    " ------------ | :-----------: | -----------: | \n" +
    "Content       |          *Long Cell*        || \n" +
    "Content       |   **Cell**    |         Cell | \n" +
    "                                               \n" +
    "New section   |     More      |         Data | \n" +
    "And more      | With an escaped '\\|'       || \n" +
    "[Prototype table]                              \n";

    console.log(md.render(exampleTable));

$ node test.js > test.html
$ firefox test.html

Here's the table expected on browser:

Noted that GitHub filters out style property, so the example uses align the
obsolete one. However it outputs style="text-align: ..." in actual.

Options

Multiline

Backslash at end merges with line content below.

Feature contributed by Lucas-C.

 |   Markdown   | Rendered HTML |
|--------------|---------------|
|    *Italic*  | *Italic*      | \
|              |               |
|    - Item 1  | - Item 1      | \
|    - Item 2  | - Item 2      |
|    ```python | ```python       \
|    .1 + .2   | .1 + .2         \
|    ```       | ```           |

This is parsed below when the option enabled:

*Italic*

- Item 1
- Item 2

```python
.1 + .2
```

.1 + .2

Rowspan

^^ indicates cells being merged above.

Feature contributed by pmccloghrylaing.

 Stage | Direct Products | ATP Yields
----: | --------------: | ---------:
Glycolysis | 2 ATP ||
^^ | 2 NADH | 3--5 ATP |
Pyruvaye oxidation | 2 NADH | 5 ATP |
Citric acid cycle | 2 ATP ||
^^ | 6 NADH | 15 ATP |
^^ | 2 FADH2 | 3 ATP |
**30--32** ATP |||
[Net ATP yields per hexose]

This is parsed below when the option enabled:

Headerless

Table header can be eliminated.

 |--|--|--|--|--|--|--|--|
|♜|  |♝|♛|♚|♝|♞|♜|
|  |♟|♟|♟|  |♟|♟|♟|
|♟|  |♞|  |  |  |  |  |
|  |♗|  |  |♟|  |  |  |
|  |  |  |  |♙|  |  |  |
|  |  |  |  |  |♘|  |  |
|♙|♙|♙|♙|  |♙|♙|♙|
|♖|♘|♗|♕|♔|  |  |♖|

This is parsed below when the option enabled:

Multibody

An empty line separates consecutive table bodies. When disabled, an empty line
always cuts off the tables.

Autolabel

Table id attribute follows the table caption if not labeled. When disabled,
caption without labels cannot generate the attribute.

Credits

• MultiMarkdown, Lightweight
  markup processor to produce HTML, LaTeX, and more.
• markdown-it, Markdown parser, done right.
  100% CommonMark support, extensions, syntax plugins & high speed.

License

This software is licensed under the MIT license © RedBug312.