Fast front matter extraction and strict YAML-subset decoding for PHP.

ALTO Front Matter extracts fenced metadata from documents and exposes it through typed, read-only accessors. Its dependency-free decoder implements a strict YAML subset and rejects unsupported syntax with precise source coordinates instead of silently reinterpreting input.

<?php

use Alto\FrontMatter\FrontMatter;

$metadata = FrontMatter::fromString("---\ntitle: Hello\n---\nArticle body\n");
echo $metadata->getString('title');

The example prints Hello.

Documentation

  • Installation: install the package and verify its requirements.
  • Getting started: read metadata and recover the document body.
  • Metadata: access typed values, defaults, enums, and dates.
  • Decoding: understand the supported YAML subset and its limits.
  • Rendering: generate YAML, JSON, or TOML front matter.
  • Integration: use or replace the decoder and renderer contracts.
  • Errors: handle syntax, type, format, and file failures.

Boundaries

The default decoder accepts YAML front matter only. TOML can be rendered but requires a custom decoder for input. The returned metadata records where the front matter appeared; the caller retains ownership of the original document and its body.