FlatMatter

A YAML-like data serialization language with support for functions. FlatMatter is considered feature-complete and is intentionally kept simple. Bug fixes and performance improvements are still made, of course.

Example FlatMatter:

title: "My Blog"
last_updated: (get-content "posts") / (limit 1) / (get "published_at") / (date "YYYY-mm-dd")
posts: "posts" / get-content

FlatMatter aims to be more-or-less syntactically compatible with YAML for the simple reason of not needing new editor plugins to have syntax highlighting, but it differs in that there is no indentation, but instead dots to indicate hierarchy, like site.title which would result in a site object that contains the title key.

FlatMatter also supports functions, allowing you to build your own data DSL, and functions can also be piped with the forward slash / character, meaning that the result of the left operation will be passed as the first argument of the next function, and so on, to produce an end result.

Additionally, FlatMatter also parses FrontMatter content, meaning that a FlatMatter file like this:

---
title: "Hello, World!"
---
Content goes here.

Would result in this data being created:

{
  "title": "Hello, World!",
  "content": "Content goes here."
}

Install

npm i flatmatter

Usage

The most basic usage looks like this:

import FlatMatter from "flatmatter";

const config = FlatMatter.config('key: "value"');

// {key: "value"}

However, you most likely want to use it with functions. Those you have to create yourself.

const toUpper = {
  name: 'to-upper',
  compute: (input: string): unknown => {
    return input.toUpperCase();
  }
}

A FlatMatter function has to have a name property and a compute callable which takes a string and returns something. And, like I mentioned before, a thing to keep in mind is that if the function is piped, the first argument passed to it will be the result of the previous operation.

Once you have your functions, simply pass them to FlatMatter like this:

import FlatMatter from "flatmatter";

const config = FlatMatter.config('key: "value" / to-upper', [toUpper]);

// {key: "VALUE"}