Customizing Frontmatter

Prezet makes it easy to add custom fields to your markdown frontmatter. This guide shows you how to extend Prezet's FrontmatterData class to add your own typed fields.

Prezet's default frontmatter includes fields like title, excerpt, date, category, image, author, and more. For a complete list, see FrontmatterData.php. For more on how frontmatter works in Prezet, see the Frontmatter documentation.

#Adding Custom Fields

You can extend the default frontmatter class to add your own fields. This documentation site uses a custom legacy field to power the version selector dropdown menu, allowing users to switch between current and legacy documentation.

#1. Create Your Custom Class

Create a new class that extends FrontmatterData:

<?php

namespace App\Data;

use Prezet\Prezet\Data\FrontmatterData;
use WendellAdriel\ValidatedDTO\Attributes\Rules;

class CustomFrontmatterData extends FrontmatterData
{
    #[Rules(['nullable', 'bool'])]
    public ?bool $legacy;
}

#2. Use in Your Frontmatter

Add the custom field to your markdown files:

---
title: My Old Docs
date: 2023-01-01
legacy: true
---

#3. Register Your Class

Bind your custom class in app/Providers/AppServiceProvider.php:

use Prezet\Prezet\Data\FrontmatterData;
use App\Data\CustomFrontmatterData;

public function register(): void
{
    $this->app->bind(FrontmatterData::class, CustomFrontmatterData::class);
}

Now Prezet will use your CustomFrontmatterData class whenever it processes frontmatter, making your custom fields available throughout the application.