Domain Model

Modeling Aggregates, Entities and Value Objects

Complex Heart allows you to model your domain Aggregates, Entities, and Value Objects using a set of traits. Great, but why traits and not classes? Well, sometimes you have some kind of inheritance in your classes. Being forced to use a certain base class is too invasive and personally, I don't like it. By using a set of traits and interfaces you have all the functionality you need without compromising the essence of your own domain.

The available traits are:

• HasAttributes Provide some functionality to manage attributes.
• HasEquality Provide functionality to handle equality between objects.
• HasInvariants Allow invariant checking on instantiation (Guard Clause).
• HasIdentity Define the Entity/Aggregate identity.
• HasDomainEvents Provide domain event management.

On top of those base traits Complex Heart provide ready to use compositions:

• IsModel composed by HasAttributes and HasInvariants.
• IsValueObject composed by IsModel and HasEquality.
• IsEntity composed by IsModel, HasIdentity, HasEquality.
• IsAggregate composed by IsEntity, HasDomainEvents.

Key Features

• Type-Safe Factory Method: The make() static factory validates constructor parameters at runtime with clear error messages
• Automatic Invariant Checking: When using make(), Value Objects and Entities automatically validate invariants after construction (no manual $this->check() needed)
• Named Parameter Support: Full support for PHP 8.0+ named parameters for improved readability and flexibility
• Union Type Support: Complete support for PHP 8.0+ union types (e.g., int|float, string|null)
• Readonly Properties Support: Full compatibility with PHP 8.1+ readonly properties
• PHPStan Level 8: Complete static analysis support

Note: Automatic invariant checking only works when using the make() factory method. Direct constructor calls require manual $this->check() in the constructor.

For more information and usage examples, please check the wiki.