PHP DTO

A PHP library to map associative arrays to typed DTOs using attributes.

Installation

Install from Packagist:

composer require rjds/php-dto

Requirements:

• PHP 8.1 or higher

Overview

DtoMapper converts associative arrays to typed constructor-based DTOs.

use Rjds\PhpDto\Attribute\ArrayOf;
use Rjds\PhpDto\Attribute\CastTo;
use Rjds\PhpDto\Attribute\MapFrom;
use Rjds\PhpDto\DtoMapper;

final class TagDto
{
    public function __construct(
        public readonly string $name,
        public readonly string $url,
    ) {
    }
}

final class ArtistDto
{
    /** @param list<TagDto> $tags */
    public function __construct(
        public readonly string $name,
        #[MapFrom('stats.play_count')]
        #[CastTo('int')]
        public readonly int $playCount,
        #[ArrayOf(TagDto::class)]
        public readonly array $tags,
    ) {
    }
}

$mapper = new DtoMapper();

$artist = $mapper->map([
    'name' => 'Arctic Monkeys',
    'stats' => ['play_count' => '150316'],
    'tags' => [
        ['name' => 'rock', 'url' => 'https://www.last.fm/tag/rock'],
        ['name' => 'indie', 'url' => 'https://www.last.fm/tag/indie'],
    ],
], ArtistDto::class);

echo $artist->playCount;   // 150316 (int)
echo $artist->tags[0]->name; // rock

Features

• Zero-boilerplate name-based mapping for constructor arguments
• #[MapFrom] support for renamed and nested keys using dot notation
• #[CastTo] support for int, float, string, bool, and datetime
• #[ArrayOf] support for mapping nested DTO collections
• Constructor default values respected when source keys are missing

Quick Reference

#[MapFrom]

Map a parameter from a different key, including nested paths:

#[MapFrom('profile.first_name')]
public readonly string $firstName

#[CastTo]

Cast scalar string input into strongly typed DTO fields:

#[CastTo('datetime')]
public readonly \DateTimeImmutable $registeredAt

#[ArrayOf]

Map list entries to nested DTO instances:

#[ArrayOf(TagDto::class)]
public readonly array $tags

Development

composer install
php vendor/bin/grumphp run

Run mutation testing:

php vendor/bin/infection --threads=4

Contributing

Contributions are welcome. See CONTRIBUTING.md for branch strategy, commit conventions, and PR workflow.

License

This project is released under the MIT License. See LICENSE for details and CHANGELOG.md for release history.