Getting Started

Introduction

Carapace is a lightweight PHP library for building immutable, strictly typed Data Transfer Objects (DTOs).

It leverages PHP attributes for casting, property mapping, and serialization, while providing a simple, expressive API.

Features

Immutable DTOs

• Define immutable data objects by extending the ImmutableDTO base class.
• Properties are initialized via constructor promotion.
• Enforces strict immutability for data integrity.

Attribute-Driven Mapping

• CastWith
  Automatically casts values during hydration:
  • Nested DTOs and collections
  • Primitive types (int, float, string, bool, array)
  • PHP enums (backed and unit enums)
  • Custom types via CasterInterface
• MapFrom
  Maps properties from custom keys in the input array.
• MapTo
  Controls output keys when serializing the DTO.
• Hidden
  Excludes properties from serialization output.

Serialization

• Convert DTOs to arrays or JSON using built-in methods.
• Supports deep, recursive serialization of nested DTOs.

Installation

composer require alamellama/carapace

Requirements

• PHP 8.2 or higher