README

MiniYAML is a minimalistic YAML loader and dumper for PHP. It handles the subset of YAML commonly used for configuration files and API responses.

Why MiniYAML?

• Single file, zero dependencies. Drop miniyaml.php into your project and you are done — no Composer, no autoloader, no transitive dependencies.
• Tiny footprint. The entire implementation is ~350 lines of straightforward PHP.
• PHP template evaluation. The built-in InterpretPHP() method lets you embed <?= $var ?> tags directly in YAML, making it easy to build environment-specific configuration without a separate templating step. No other mainstream YAML library offers this.
• Readable API. Three static methods — Load(), Dump(), InterpretPHP() — cover all common use cases without configuration overhead.
• Runs on PHP 5.6 and up. Works on legacy hosting and old codebases where modern libraries have already dropped support.

Installation

composer require atk14/mini-yaml

Usage

Load

$ar = miniYAML::Load($yaml_string);

Options:

// Disable null handling — "null" is kept as a plain string
$ar = miniYAML::Load($yaml_string, ["nullable" => false]);

// Evaluate embedded PHP
$yaml = miniYAML::Load($template, [
    "interpret_php" => true,
    "values" => ["domain" => "example.com"],
]);

Dump

$yaml = miniYAML::Dump($array);

Options:

$yaml = miniYAML::Dump($array, ["nullable" => false]);

Supported YAML features

Load and Dump:

• Hash (associative) arrays: key: value
• Indexed (list) arrays: - item
• Nested structures of arbitrary depth
• Empty arrays: []
• Quoted strings: "value" and 'value'
• null / NULL values (controlled by the nullable option)
• Comments: lines starting with #

Load only:

• Literal block scalars (|) — newlines preserved
• Folded block scalars (>) — newlines replaced with spaces

Dump only:

• Strings containing newlines are automatically serialized as literal block scalars (|)
• Strings requiring escaping (colons, special characters, YAML keywords, …) are wrapped in double quotes

Example

$yaml = '
---
status: success
message: Ok
data:
  domain: example.com
  admin:
  - Alice
  - Bob
  description: |
    First line.
    Second line.
';

$ar = miniYAML::Load($yaml);
// [
//   "status"  => "success",
//   "message" => "Ok",
//   "data"    => [
//     "domain"      => "example.com",
//     "admin"       => ["Alice", "Bob"],
//     "description" => "First line.\nSecond line.",
//   ]
// ]

echo miniYAML::Dump($ar);

Limitations

The following YAML features are not supported:

• Multiline plain scalars (without | or >)
• Anchors and aliases (&, *)
• Explicit type tags (!!str, !!int, …)
• Flow mappings and sequences ({…}, […]) — except empty array []
• Documents with a common base indentation on all lines

MiniYAML is well-suited for YAML you write and control yourself. If the input comes from an external tool or another language, it may use syntax that MiniYAML silently misparses or ignores.

Alternatives

If MiniYAML does not cover your use case, consider these alternatives:

Testing

composer update --dev
./vendor/bin/run_unit_tests test

License

MiniYAML is free software distributed under the terms of the MIT license