DDD in PHPon example of Symfony

cystbearSymfony expert

MongoDB adept

Erlang fun

OSS doer

KNPer

https://twitter.com/1cdecoderhttps://github.com/cystbearhttp://knplabs.com/

Learning Pyramid

PHP? ORLY?

What this talk about?

About useful tool/lib?

About success story?

No! It’s about idea

Motivation!

MVC

Where to store business logic?

ModelViewController

Where to store business logic?

ModelViewController

Where to store business logic?

ModelViewController

Where to store business logic?

ModelViewController -- YEAH!

Welcome to

Fat Stupid Ugly ControllersFSUC/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/

Anemic (Domain) Model

http://www.martinfowler.com/bliki/AnemicDomainModel.htmlhttp://habrahabr.ru/post/224879/

“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

Persistence Layer

Model

What is

Not MVC (phew!)

Request / Response FrameworkHTTP Framework

http://fabien.potencier.org/article/49/what-is-symfony2

What about model,persistence layer?

Meet Doctrine

http://www.doctrine-project.org/

SQL -- DBAL + ORMMongoDBCouchDBOrientDBPHPCR ODMOXM

What is

Inversion of controlService LocatorDependency Injection Container

http://www.martinfowler.com/articles/injection.htmlhttp://fabien.potencier.org/article/11/what-is-dependency-injection

Services

http://groovy.codehaus.org/https://grails.org/

Single ClassWith its Deps (min) setEasy to ReplaceEasy to Test

MVC(S)!

Controller’s pray

https://twitter.com/ornicar

Get RequestSubmit form if anyCall one Service methodReturn Response

Rendering HTML far away

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>

Real Painclass BackendUserProgramsPossessionFormHandler{ protected $dep1; // deps holder props

public function __construct(DepsClass $dep1 /*, ...*/) { $this->dep1 = $dep1; }

public function process(Form $form) { $this->dep1->makeHappy($form); // ... }

How Kris writes Symfony apps#44

https://twitter.com/kriswallsmithhttp://www.slideshare.net/kriswallsmith/how-kris-writessymfonyapps

https://twitter.com/kriswallsmithhttp://www.slideshare.net/kriswallsmith/how-kris-writessymfonyapps

How Kris writes Symfony apps#44

Domain Logic Patterns

http://martinfowler.com/books/eaa.html

Domain Logic Patterns

http://martinfowler.com/books/eaa.html

Transaction ScriptDomain ModelTable ModuleService Layer

Transaction Script

Domain Model

Table Module

Domain Logic&

Application logic

Service Layer

What is next?RADDDD PatternsExamplesLayersGoodies

DDD != RADCode FirstDo not Care about persistence (yet)

Domain ModelRepositoryValue ObjectDTOStrategyState

Patterns & Code

Domain Model

Domain Model<?php

namespace MegaCorp\Core\Product;

class Product{ private $id; private $name; private $recognitionStrategy;

public function __construct( ProductId $id, $name, $recognitionStrategy ) { $this->id = $id; $this->name = $name; $this->recognitionStrategy = $recognitionStrategy; }

Repository<?php

namespace MegaCorp\Core\Product;

interface ProductRepository{ public function find(ProductId $productId);

public function findAll();

public function add(Product $product);

public function remove(Product $product);}

Value Object<?php

namespace MegaCorp\Core;

class ProductId{ private $value;

public function __construct($value) { $this->value = (string) $value; }

public function getValue() { return $this->value; }}

Value Object DateRange

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)

Value Object Money

<?php

class Money{ private $amount; private $currency;

public function __construct($amount, Currency $currency) { // ... }}

Value Object Money

<?php

class ProfileData{ public $firstName; public $lastName; public $birthday;}

DTO

Strategy

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

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

Directory structure

Layers

LayersDomain Layer -- heart of your application, Entities and Repositories

Application Layer -- ControllersPresentation Layer -- Templates / DTOs for serializerInfrastructure Layer -- framework, persistence, concrete implementations of Domain Layer

Useful goodies

BBB DDD by Eric Evans

http://amzn.com/0321125215/

DDD Quickly by InfoQ

http://www.infoq.com/minibooks/domain-driven-design-quickly

PoEAA by Martin Fowler

http://amzn.com/B008OHVDFM/

DDD and Patterns by Jimmy Nilsson

http://amzn.com/B0054KOKQQ/

Linkshttp://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.aspxhttp://www.martinfowler.com/bliki/AnemicDomainModel.htmlhttp://martinfowler.com/bliki/CQRS.html

https://joind.in/11576

Thanks!