DDD Embeddables
, (*1)
A collection of reusable value objects written in PHP and targeting versions 8.0 and above. Value objects are essential building blocks of Domain Driven Design approach and described by Martin Fowler in P of EAA page 486 as below:, (*2)
"Value object is a small simple object, like money or a date range, whose equality isn't based on identity.", (*3)
– Martin Fowler, (*4)
All classes in this library annotated as ORM\Embeddable with appropriately adjusted column attributes. This makes them ready to use in any project with Doctrine ORM as Embeddables., (*5)
Installation & Usage
Install the library using composer., (*6)
$ composer require biberlabs/ddd-embeddables
and use it in your entities:, (*7)
<?php
namespace MyApp\Entity;
use Doctrine\ORM\Mapping as ORM;
use DDD\Embeddable\EmailAddress;
/**
* @ORM\Entity
*/
class User {
/**
* @ORM\Embedded(class="DDD\Embeddable\EmailAddress")
*/
private $email;
// Returns an EmailAddress instance, not a string
public function getEmail();
// Use type-hinting if you need a setter
public function setEmail(EmailAddress $email);
}
Afterwards, you can write custom DQL queries based on your requirements while accessing properties of the value objects such as:, (*8)
SELECT u FROM User u WHERE u.email = :email
-- OR
SELECT p FROM Payments p WHERE p.total.currency = :currency
SELECT p FROM Payments p WHERE p.total.amount > 1000
-- OR
SELECT u FROM User u WHERE u.name.surname = :surname
SELECT u FROM User u WHERE u.name.title = :title
Value objects enables us to write much more cleaner and readable rules when dealing with the domain rules, application-wide. For example:, (*9)
$username = $user->getEmail()->getLocalpart();
or, (*10)
$blacklist = ['spam4me.io', 'foo.com'];
if(in_array($user->getEmail()->getDomain(), $blacklist)) {
// ...
}
even, (*11)
if($company->hasMap()) {
$latLng = $company->getAddress()->getGeoPoint()->toArray();
//..
}
class Company
{
// ...
/**
* Returns a boolean TRUE if the geolocation of the company is known,
* FALSE otherwise.
*
* @return bool
*/
public function hasMap()
{
return $this->getAddress()->getGeoPoint() !== null;
}
}
Running Tests
You can run unit tests locally via issuing the command below:, (*12)
$ composer test
Please make sure that all test are green before creating a PR., (*13)
PHPUnit 9.5.25 #StandWithUkraine
................................................................. 65 / 75 ( 86%)
.......... 75 / 75 (100%)
Time: 00:00.037, Memory: 6.00 MB
OK (75 tests, 124 assertions)
Contributing
If you want to contribute to ddd-embeddables and make it better, your help is very welcome., (*14)
Please take a look our CONTRIBUTING.md before creating a pull request., (*15)
Further Reading
Are you interested in Domain Driven Design? Here is a list of good resources to dig in-depth., (*16)
Wallogit.com
