README

A curated set of reusable, semantic domain exceptions for Domain-Driven Design (DDD) PHP applications.

This package is framework-agnostic — zero runtime dependencies beyond the PHP standard library. It was extracted from hradigital/php-datatypes so it can evolve independently and be reused across any PHP 8.1+ project.

Why this package?

These are domain exceptions, not HTTP exceptions. Their names and intent mirror the HTTP 4XX/5XX status families because the vocabulary is widely understood — but they are meant to be raised in the domain layer, outside any transport, and translated to a transport-specific representation (HTTP response, RPC error, CLI exit, queue dead-letter) at the boundary.

Throwing the right exception is part of your domain language. Generic \InvalidArgumentException or \RuntimeException leak plumbing concerns into the domain. This library gives you:

• Semantic, intent-revealing exception types organised into Client (caller-fault, 4XX-aligned) and Server (system-fault, 5XX-aligned) families.
• A common abstract base (AbstractBaseException) that extends \DomainException so a single catch can capture everything in this package.
• No framework lock-in — pure PHP, drop it into any application or framework.

Requirements

Installation

composer require hradigital/php-exceptions

Usage

Every exception in this package extends AbstractBaseException, which itself extends PHP's native \DomainException. Each subclass ships with a sensible default message and an HTTP-aligned status code ($code).

use HraDigital\Components\Exceptions\Client\NotFoundException;

throw new NotFoundException('User #42 does not exist.');

Catching by intent

use HraDigital\Components\Exceptions\AbstractBaseException;
use HraDigital\Components\Exceptions\Client\ConflictException;
use HraDigital\Components\Exceptions\Client\NotFoundException;
use HraDigital\Components\Exceptions\Client\UnprocessableEntityException;

try {
    $service->updateProfile($payload);
} catch (UnprocessableEntityException $e) {
    // input parsed but failed business-rule validation
} catch (NotFoundException $e) {
    // target aggregate / entity does not exist
} catch (ConflictException $e) {
    // current state of the aggregate refuses this action
} catch (AbstractBaseException $e) {
    // any other domain failure raised by this package
}

Authoring your own exceptions

Pick the closest leaf class and extend it — that way callers can still catch by the broader intent.

use HraDigital\Components\Exceptions\Client\ConflictException;

class EmailAlreadyTakenException extends ConflictException
{
    protected $message = 'The provided email is already in use.';
}

Available exceptions

Listed in HTTP-status order for orientation. Each class carries a docBlock with its semantic meaning, when to extend it, and (where relevant) the browser behaviour the analogous HTTP status triggers.

Client — caller-fault (4XX-aligned) BadRequestException (400), DeniedAccessException (401), PaymentRequiredException (402), ForbiddenException (403), NotFoundException (404), MethodNotAllowedException (405), NotAcceptableException (406), RequestTimeoutException (408), ConflictException (409), GoneException (410), PreconditionFailedException (412), UnsupportedMediaTypeException (415), RequestedRangeNotSatisfiableException (416), ExpectationFailedException (417), UnprocessableEntityException (422), LockedException (423), FailedDependencyException (424), TooEarlyException (425), PreconditionRequiredException (428), TooManyRequestsException (429), UnavailableForLegalReasonsException (451), plus Request\RequestFailureException for structured per-field validation failures.

Server — system-fault (5XX-aligned) InternalServerErrorException (500), ServerNotImplementedException (501), BadGatewayException (502), ServerUnavailableException (503), GatewayTimeoutException (504), InsufficientStorageException (507), LoopDetectedException (508).

Transport-only HTTP statuses (407, 411, 413, 414, 421, 426, 431, 505, 506, 510, 511) are intentionally not represented — they have no platform-agnostic domain meaning.

Testing

composer install
composer test

Continuous Integration

GitHub Actions runs PHPUnit on every push and pull request, across PHP 8.1 / 8.2 / 8.3 / 8.4.

Versioning

This package follows Semantic Versioning 2.0.0. Breaking changes only ship in major releases.

Contributing

Pull requests are welcome. For substantial changes, please open an issue first to discuss what you'd like to change. Add tests for any new behaviour or bug fix.

Security

If you discover a security vulnerability, please email github@hradigital.com instead of opening a public issue.

License

This package is open-sourced software licensed under the GNU General Public License v3.0 or later.