Remark-Tangle

Remark and mdast plugins for creating interactive markdown documents.

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Remark-Tangle extends plain text markdown with a special notation (based on links) for adding controls and variables with Tangle. It's like a lightweight and inline version of Jupyter, Observable, R, or Wolfram notebooks. Or, if you like, a messier alternative to spreadsheets.

A sample Model-Driven Markdown file looks like this:

### How many cookies?


When you eat [3 cookies](cookies=[0..100]), you consume **[150 calories](calories)**. 
That's [7.5%](daily_percent&margin-right=0.5ch) of your recommended daily calories.


| Calculation for daily % |                         |
| ----------------------- | ----------------------- |
| [`cookies`](cookies) | = [5 cookies](cookies&margin-left=1ch) |
| [`calories_per_cookie`](calories_per_cookie) | = [50 calories](calories_per_cookie=[10..100;5]&margin-left=1ch) | 
| [`calories`](calories) | = [`calories_per_cookie`](calories_per_cookie&margin-left=1ch&margin-right=1ch)*[`cookies`](cookies&margin-left=1ch&margin-right=1ch) = [150 calories](calories=calories_per_cookie*cookies&margin-left=1ch) |
| [`calories_per_day`](calories_per_day) | = [2000 calories](calories_per_day=[0..10000;100]&margin-left=1ch) |
| [`daily_percent`](daily_percent) | = [`calories`](calories&margin-left=1ch&margin-right=1ch)/[`calories_per_day`](calories_per_day&margin-left=1ch&margin-right=1ch) = [7.5%](daily_percent=calories/calories_per_day&margin-left=1ch) |

And, when compiled to html, yields a page that looks like this :

The best part about the format (IMHO) is that it has a clean fallback in standard HTML (as long as you can ignore broken links):

How many cookies?

When you eat 3 cookies, you consume 150 calories. That's 7.5% of your recommended daily calories.

Calculation for daily %
cookies	= 5 cookies
calories_per_cookie	= 50 calories
calories	= calories_per_cookie*cookies = 150 calories
calories_per_day	= 2000 calories
daily_percent	= calories/calories_per_day = 7.5%

For a more in-depth example, take a look at this post introducing remark-tangle.

Structure

The project exports a plugin from /dist/index.js that you should use after remarkParse and before remarkRehype.

How to use

To get this to work with Next.js, I've had to downgrade hastscript -> hastscript@^6.0.0 and unist-util-visit@^2.0.1.

The unified plugin ecosystem is making a push to full esm modules, but next.config.js only allows require imports.

When next.js makes the transition, I'll deprecate the commonjs build.

Notation

The default notation takes advantage of link notation to provide a clean fallback in standard markdown. Tangle fields take the format: [display string](variable-configuration).

There's an alternative notation via remark-directive if you prefer to leave your links untouched: :t[display string]{variable configuration}.

For example:

• :t[3 cookies]{num_cookies=[1..10;.5]} defines a variable, num_cookies, with default value 3, display template %d cookies (using inferred printf notation), that can take values from the range 1 to 10 inclusive, with step size 0.5.
• :t[150. calories]{num_calories=num_cookies*num_calories_per_cookie} defines a variable, num_calories that depends on the values of num_cookies and num_calories_per_cookie, with display template %.0f calories.
• :t[150 calories]{num_calories} creates a reference to a variable already defined elsewhere. These are automatically synchronized.

See the reference for a full account of different types of fields and their configuration.

Note: you can add other key-value pairs to customize the styling (which is useful for spacing). Use the separator & in link format and a blank space in directive-format: [5 cookies](cookies=[0..10]&margin-left=1ch) vs. :t[5 cookies]{cookies=[0..10] margin-left=1ch}

Timeline

There's still a lot to do.

1. Syncing hovers & actives. If you scroll over a field, you should see any references to and dependencies of that field light up.
2. More inputs & more data types (such as lists/distributions).
3. Replacing Tangle, which hasn't been maintained in over a decade. It's time to move on.

Security

This opens you up for some serious XSS vulnerabilities. Be careful, know what you are doing.

Contribute

This project is still very early on, so I welcome any kind of support you might want to offer.

Authors

• Jesse Hoogland

The concepts and notation are inspired by a bunch of different projects:

• 🙌 Tangle by Bret Victor is at the root of all of these projects.
• Active Markdown by Alec Perkins most inspired the syntax.
• Dynamic Markdown by Tal Lorberbaum
• Fangle by @jotux
• TangleDown by Nicholas Bollweg

License

MIT © Jesse Hoogland