DDD in PHP on example of Symfony Олег Зинченко В докладе речь пойдет о том, что такое DDD и почему MVC годами вводит нас в заблуждение. Как автор пришёл к мысли о том, что просто писать структурированный код недостаточно. Будут описаны слои приложения DDD, как они взаимодействуют между собой. Какие архитектурные паттерны стоят за DDD и почему они облегчают жизнь разработчика. Когда лучше использовать DDD, какие достоинства и недостатки есть у этого подхода. Примеры использованиея DDD подхода в Symfony приложениях.

1. DDD in PHP
on example of Symfony

2. cystbear
Symfony expert
MongoDB adept
Erlang fun
OSS doer
KNPer
https://twitter.com/1cdecoder
https://github.com/cystbear
http://knplabs.com/

3. Learning Pyramid

4. PHP? ORLY?

5. What this talk about?

6. About useful tool/lib?

7. About success story?

8. No! It’s about idea
Motivation!

9. MVC

10. Where to store business logic?
Model
View
Controller

11. Where to store business logic?
Model
View
Controller

12. Where to store business logic?
Model
View
Controller

13. Where to store business logic?
Model
View
Controller -- YEAH!

14. Welcome to
Fat Stupid Ugly Controllers
FSUC/FUC
http://blog.astrumfutura.com/2008/12/the-m-in-mvc-why-models-are-misunderstood-and-unappreciated/
http://zendframework.ru/anonses/model-with-mvc
http://habrahabr.ru/post/175465/

15. Anemic (Domain) Model
“In essence the problem with anemic domain
models is that they incur all of the costs of a domain
model, without yielding any of the benefits.”
Martin Fowler
http://www.martinfowler.com/bliki/AnemicDomainModel.html
http://habrahabr.ru/post/224879/

16. Model
Persistence Layer

18. What is
Not MVC (phew!)
Request / Response Framework
HTTP Framework
http://fabien.potencier.org/article/49/what-is-symfony2

19. What about model,
persistence layer?

20. Meet Doctrine
http://www.doctrine-project.org/
SQL -- DBAL + ORM
MongoDB
CouchDB
OrientDB
PHPCR ODM
OXM

21. What is
Inversion of control
Service Locator
Dependency Injection Container
http://www.martinfowler.com/articles/injection.html
http://fabien.potencier.org/article/11/what-is-dependency-injection

22. Services
http://groovy.codehaus.org/
https://grails.org/
Single Class
With its Deps (min) set
Easy to Replace
Easy to Test
MVC(S)!

23. Controller’s pray
https://twitter.com/ornicar
Get Request
Submit form if any
Call one Service method
Return Response
Rendering HTML far away

24. Managers Managers Managers
http://blog.codinghorror.com/i-shall-call-it-somethingmanager/
http://stackoverflow.com/questions/1866794/naming-classes-how-to-avoid-
calling-everything-a-whatevermanager
<SmtManager>
<WhatEverManager>
<MyManager>
<EtcManager>

25. Real Pain
class BackendUserProgramsPossessionFormHandler
{
protected $dep1; // deps holder props
public function __construct(DepsClass $dep1 /*, ...*/)
{
$this->dep1 = $dep1;
}
public function process(Form $form)
{
$this->dep1->makeHappy($form);
// ...
}

26. How Kris writes Symfony apps#44
https://twitter.com/kriswallsmith
http://www.slideshare.net/kriswallsmith/how-kris-writessymfonyapps

27. How Kris writes Symfony apps#44
https://twitter.com/kriswallsmith
http://www.slideshare.net/kriswallsmith/how-kris-writessymfonyapps

28. Domain Logic Patterns
http://martinfowler.com/books/eaa.html

29. Domain Logic Patterns
http://martinfowler.com/books/eaa.html
Transaction Script
Domain Model
Table Module
Service Layer

30. Transaction Script

31. Domain Model

32. Table Module

33. Domain Logic
&
Application logic

34. Service Layer

36. What is next?
RAD
DDD Patterns
Examples
Layers
Goodies

37. DDD != RAD
Code First
Do not Care about persistence (yet)

38. Patterns & Code
Domain Model
Repository
Value Object
DTO
Strategy
State

39. Domain Model

40. Domain Model
<?php
namespace MegaCorpCoreProduct;
class Product
{
private $id;
private $name;
private $recognitionStrategy;
public function __construct(
ProductId $id, $name, $recognitionStrategy
) {
$this->id = $id;
$this->name = $name;
$this->recognitionStrategy = $recognitionStrategy;
}

41. Repository
<?php
namespace MegaCorpCoreProduct;
interface ProductRepository
{
public function find(ProductId $productId);
public function findAll();
public function add(Product $product);
public function remove(Product $product);
}

42. Value Object
<?php
namespace MegaCorpCore;
class ProductId
{
private $value;
public function __construct($value)
{
$this->value = (string) $value;
}
public function getValue()
{
return $this->value;
}
}

43. Value Object DateRange

44. Value Object DateRange
<?php
public function findByDateRange(
DateTime $from, DateTime $to )
class DateRange
{
private $from;
private $to;
public function __construct(DateTime $from, DateTime $to)
{
$this->from = $from;
$this->to = $to;
}
}
public function findByDateRange(DateRange $range)

45. Value Object Money

46. <?php
class Money
{
private $amount;
private $currency;
public function __construct($amount, Currency $currency)
{
// ...
}
}
Value Object Money

47. <?php
class ProfileData
{
public $firstName;
public $lastName;
public $birthday;
}
DTO

48. Strategy

49. ______ ______ _______ _______
/ | / __ | | ____|
| ,----'| | | | | .--. || |__
| | | | | | | | | || __|
| `----.| `--' | | '--' || |____
______| ______/ |_______/ |_______|

50. src
└── MegaCorp
Directory structure
├── ApiBundle
│ ├── Controller
│ │ └── ...
│ └── MegaCorpApiBundle.php
├── Core
│ └── Product
│ ├── Product.php
│ ├── ProductId.php
│ └── ProductRepository.php
└── CoreBundle
├── Controller
│ └── ...
├── Repository
│ ├── InMemoryProductRepository.php
│ └── MongoDbProductRepository.php
└── MegaCorpCoreBundle.php

51. Layers

52. Layers
Domain Layer -- heart of your application, Entities and Repositories
Application Layer -- Controllers
Presentation Layer -- Templates / DTOs for serializer
Infrastructure Layer -- framework, persistence, concrete
implementations of Domain Layer

53. Useful goodies

54. BBB DDD by Eric Evans
http://amzn.com/0321125215/

55. DDD Quickly by InfoQ
http://www.infoq.com/minibooks/domain-driven-design-quickly

56. PoEAA by Martin Fowler
http://amzn.com/B008OHVDFM/

57. DDD and Patterns by Jimmy Nilsson
http://amzn.com/B0054KOKQQ/

58. Links
http://dddcommunity.org/
http://williamdurand.fr/
http://welcometothebundle.com/
http://verraes.net/
http://jimmynilsson.com/blog/
http://www.martinfowler.com/
http://elephantintheroom.io/ -- podcast
http://msdn.microsoft.com/en-us/magazine/dd419654.aspx
http://www.martinfowler.com/bliki/AnemicDomainModel.html
http://martinfowler.com/bliki/CQRS.html

60. Thanks!
https://joind.in/11576