frontmatter()

Create a frontmatter plugin that enables parsing of YAML, TOML, or JSON metadata blocks at the top of Markdown/MDX documents.

import { frontmatter } from "@unifast/node";

Signature

function frontmatter(options?: FrontmatterPluginOptions): UnifastPlugin

Parameters

options?

Configuration for frontmatter formats

Property	Type	Default	Description
`yaml`	`boolean`	`true`	Enable YAML frontmatter (— delimiters)
`toml`	`boolean`	`false`	Enable TOML frontmatter (+++ delimiters)
`json`	`boolean`	`false`	Enable JSON frontmatter (;;; delimiters)

Usage

import { compile, frontmatter } from "@unifast/node";

const result = compile(md, {
  plugins: [
    frontmatter({
      yaml: true,
      toml: true,
      json: true,
    }),
  ],
});

console.log(result.frontmatter);
// { title: "My Page", date: "2024-01-01", tags: ["markdown", "docs"] }

Examples

YAML Frontmatter

import { compile, frontmatter } from "@unifast/node";

const md = `---
title: My Page
date: 2024-01-01
tags:
  - markdown
  - docs
---

# Hello`;

const result = compile(md, { plugins: [frontmatter()] });

console.log(result.frontmatter);
// { title: "My Page", date: "2024-01-01", tags: ["markdown", "docs"] }

TOML Frontmatter

import { compile, frontmatter } from "@unifast/node";

const md = `+++
title = "My Page"
date = 2024-01-01
+++

# Hello`;

const result = compile(md, { plugins: [frontmatter({ toml: true })] });

console.log(result.frontmatter);
// { title: "My Page", date: "2024-01-01" }

JSON Frontmatter

import { compile, frontmatter } from "@unifast/node";

const md = `;;;
{"title": "My Page", "draft": false}
;;;

# Hello`;

const result = compile(md, { plugins: [frontmatter({ json: true })] });

console.log(result.frontmatter);
// { title: "My Page", draft: false }