Applying Domain Driven Design when building Drupal modules with Symfony components

Talk delivered at DrupalCamp London 2015.

Transcript

1. Applying DDD when building Drupal modules using Symfony components Marek Matulka
2. Who am I?
3. Marek Matulka @super_marek mareg
4. Software Engineer at
8. Background
10. Requirement CMS - manage corporate website
11. Requirement CMS - manage corporate website - manage other brands’ websites
12. Requirement CMS - manage corporate website - manage other brands’ websites - build seasonal microsites
13. Requirement CMS - manage corporate website - manage other brands’ websites - build seasonal microsites - integrate with Magento store
15. Why Drupal? - open source CMS
16. Why Drupal? - open source CMS - easy to install and manage
17. Why Drupal? - open source CMS - easy to install and manage - most required functionality available out of the box
18. Why Drupal? - open source CMS - easy to install and manage - most required functionality available out of the box - easy to extend
19. Why Drupal 7?
22. What is Symfony?
23. is a powerful framework
24. Doctrine ORM Twig
25. set of decoupled components
27. Domain Driven Design
28. In order to create a good software, you have to know what the software is all about. – Eric Evans
29. How do we learn?
30. Stakeholders
31. Ask for examples... ...write stories!
32. Vocabulary
33. Ubiquitous Language Ubiquitous Language
34. Ubiquitous Language Ubiquitous Language Domain Expert Analyst Tester Developer Developer
35. Ubiquitous Language Ubiquitous Language Domain Expert Analyst Tester Developer Developer Application Code Acceptance Criteria Specs and documentation
36. Example?
37. Example Feature: In order to see correct prices As a visitor I need to be able to locate the nearest depot Scenario: Given I am visiting a product page for the first time And I got prompted to locate my nearest depot When I enter my post code Then I should see my local depot information
38. Example Feature: In order to see correct prices As a visitor I need to be able to locate the nearest depot Scenario: Given I am visiting a product page for the first time And I got prompted to locate my nearest depot When I enter my post code Then I should see my local depot information
39. Domain namespace Acme\Depot; interface DepotLocator { /** * @param string $postcode * * @return Depot */ public function locateDepot($postcode); }
40. Implementation namespace Acme\MagentoAdapter; use Acme\Depot\DepotLocator; class MagentoDepotLocator implements DepotLocator { public function locateDepot($postcode) { return $this->entityMapper->mapDepot( $this->clientAdapter->findDepotByPostcode($postcode) );
41. why interface?
42. Layered Architecture “High level modules should not depend on lower level implementation” – Robert C. Martin User Interface Application Domain Infrastructure
43. Dependency Inversion Policy Layer <interface> Policy Service Mechanism Layer <interface> Mechanism Service Utility Layer
44. Layered Architecture User Interface Application Domain Infrastructure
45. Layered Architecture User Interface Application Domain Infrastructure
46. Clean Architecture Entities Use Cases Controllers Web
47. Clean Architecture Entities Use Cases Controllers Web Framework Drivers Interface Adapters Application Business Rules Enterprise Business Rules
48. Hexagonal Architecture UI Adapter Log Adapter Data Storage Adapter External Data Adapter Application Domain
49. Hexagonal Architecture Acme\Depot\DepotLocator Acme\MagentoAdapter\MagentoDepotLocator
50. Hexagonal Architecture Acme\Depot\DepotLocator Acme\MagentoAdapter\MagentoDepotLocator port adapter
51. Why clean architecture?
52. Why clean architecture? - your code is clean(er)
53. Why clean architecture? - your code is clean - decoupled from framework
54. Why clean architecture? - your code is clean - decoupled from framework - reusable
55. Why clean architecture? - your code is clean - decoupled from framework - reusable - easy to test
56. Why clean architecture? - your code is clean - decoupled from framework - reusable - easy to test - easier to maintain
57. Why clean architecture? - your code is clean - decoupled from framework - re-usable - easy to test - easier to maintain - easier to change
59. When to use DDD?
60. When to use DDD? - complex domain
61. When to use DDD? - complex domain - access to domain experts
62. When to use DDD? - complex domain - access to domain experts - iterative, long term process
63. When to use DDD? - complex domain - access to domain experts - iterative, long term process - OO design
64. When not to use DDD?
65. When not to use DDD? - simple domain
66. When not to use DDD? - simple domain - data centric domains
67. When not to use DDD? - simple domain - data centric domains - prototyping
68. Symfony with Drupal 7
69. composer.json "require": { "php": ">=5.4.0", "symfony/console": "~2.5", "drush/drush": "7.*@dev", "symfony/finder": "~2.5", "symfony/dependency-injection": "~2.5", "symfony/config": "~2.5", "symfony/filesystem": "~2.6", "doctrine/dbal": "~2.5", "rhumsaa/uuid": "~2.8" },
70. AppKernel.php public function boot() { $this->container = new ContainerBuilder(); $this->container->registerExtension(new ApplicationExtension()); $loader = new YamlFileLoader($this->container, new FileLocator('app/config')); $loader->load('parameters.yml'); $loader = new XmlFileLoader($this->container, new FileLocator('/Resources/config')); $loader->load('services.xml'); $this->container->compile(); } public function getContainer() { return $this->container; }
71. settings.php require_once DRUPAL_ROOT . '/../vendor/autoload. php'; $kernel = new \Acme\Application\Kernel(); $kernel->boot(); $conf['di_container'] = $kernel->getContainer();
72. database.php $databases = [ 'default' => [ 'default' => [ 'database' => $conf['di_container']->getParameter('database.name'), 'username' => $conf['di_container']->getParameter('database.username'), 'password' => $conf['di_container']->getParameter('database.password'), 'host' => $conf['di_container']->getParameter('database.host'), 'port' => $conf['di_container']->getParameter('database.port'), 'driver' => 'mysql', 'prefix' => '', ], ], ];
73. depot_locator.module function get_depot_json($postcode) { global $conf; $depotEntity = $conf['di_container']->get('acme.depot_locator') ->locateDepot($postcode); $depot = [ 'code' => $depotEntity->getCode(), 'name' => $depotEntity->getName(), 'postcode' => $depotEntity->getPostcode(), ]; return ['depot' => $depot]; }
74. (to get Drupal 7 working with Symfony components) That’s it!
75. What I’ve learnt?
76. Drupal is a great CMS platform
77. Building your own framework is easy with Symfony Components
78. Extending Drupal 7 with Symfony components is easy
79. Questions?
80. Thank you! https://speakerdeck.com/super_marek @super_marek