Applying DDD when building Drupal modules using Symfony components (DrupalCamp CS)

Talk delivered at DrupalCamp CS 2016 in Bratislava, Slovakia.

Transcript

1. Applying DDD when building Drupal modules using Symfony components DrupalCamp CS ⚫ Bratislava ⚫ 28 May 2016
2. Who am I?
3. Marek Matulka Technical Team Lead at Inviqa @super_marek
5. Background
7. Requirement CMS - manage corporate website - manage other brands’ websites - build seasonal microsites - integrate with Magento store
9. http://photobucket.com/user/marcrobinsone/media/Drupal%20Comics/marcrobinsonegmailcom__drupalNinja.png.html
10. Why Drupal? - open source CMS - easy to install and manage - most required functionality available out of the box - easy to extend
11. Why Drupal 7?
14. What is Symfony?
15. is a powerful framework
16. Doctrine ORM Twig
17. set of decoupled components
19. Domain Driven Design
20. In order to create a good software, you have to know what the software is all about. – Eric Evans
21. How do we learn?
22. Stakeholders
23. Ask for examples... ...write stories!
24. Vocabulary
25. Ubiquitous Language Ubiquitous Language
26. Ubiquitous Language Ubiquitous Language Domain Expert Analyst Tester Developer Developer
27. Ubiquitous Language Ubiquitous Language Domain Expert Analyst Tester Developer Developer Application Code Acceptance Criteria Specs and documentation
28. Example?
29. 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
30. 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
31. Domain namespace Acme\Depot; interface DepotLocator { /** * @param string $postcode * * @return Depot */ public function locateDepot($postcode); }
32. Implementation namespace Acme\MagentoAdapter; use Acme\Depot\DepotLocator; class MagentoDepotLocator implements DepotLocator { public function locateDepot($postcode) { return $this->entityMapper->mapDepot( $this->clientAdapter->findDepotByPostcode($postcode) );
33. why interface?
34. Layered Architecture “High level modules should not depend on lower level implementation” – Robert C. Martin User Interface Application Domain Infrastructure
35. Dependency Inversion Policy Layer <interface> Policy Service Mechanism Layer <interface> Mechanism Service Utility Layer
36. Layered Architecture User Interface Application Domain Infrastructure
37. Layered Architecture User Interface Application Domain Infrastructure
38. Clean Architecture Entities Use Cases Controllers Web
39. Clean Architecture Entities Use Cases Controllers Web Framework Drivers Interface Adapters Application Business Rules Enterprise Business Rules
40. Hexagonal Architecture UI Adapter Log Adapter Data Storage Adapter External Data Adapter Application Domain
41. Hexagonal Architecture Acme\Depot\DepotLocator Acme\MagentoAdapter\MagentoDepotLocator
42. Hexagonal Architecture Acme\Depot\DepotLocator Acme\MagentoAdapter\MagentoDepotLocator port adapter
43. Why clean architecture? - your code is clean - decoupled from framework - re-usable - easy to test - easier to maintain - easier to change
45. When to use DDD? - complex domain - access to domain experts - iterative, long term process - OO design
46. When not to use DDD? - simple domain - data centric domains (CRUD, REST) - prototyping
47. Symfony with Drupal 7
48. symfony/dependency-injection symfony/config dependency injection
49. Dependency Injection - a standardised and centralised way of constructing objects in our application
50. Kernel public function boot() { $this->container = new ContainerBuilder(); $this->container->compile(); }
51. Kernel public function boot() { $this->container = new ContainerBuilder(); $loader = new YamlFileLoader($this->container, new FileLocator('app/config')); $loader->load('parameters.yml'); $this->container->compile(); }
52. Kernel public function boot() { $this->container = new ContainerBuilder(); $loader = new YamlFileLoader($this->container, new FileLocator('app/config')); $loader->load('parameters.yml'); $loader = new XmlFileLoader($this->container, new FileLocator('app/config')); $loader->load('services.xml'); $this->container->compile(); }
53. Kernel public function boot() { $this->container = new ContainerBuilder(); $loader = new YamlFileLoader($this->container, new FileLocator('app/config')); $loader->load('parameters.yml'); $loader = new XmlFileLoader($this->container, new FileLocator('app/config')); $loader->load('services.xml'); $this->container->registerExtension(new ApplicationExtension()); $this->container->compile(); }
54. Kernel public function boot() { $this->container = $this->buildContainer(); } /** * @return ContainerBuilder */ private function buildContainer() { $container = new ContainerBuilder(); $loader = new YamlFileLoader($container, new FileLocator('app/config')); $loader->load('parameters.yml'); $loader = new XmlFileLoader($container, new FileLocator('app/config')); $loader->load('services.xml'); $container->registerExtension(new ApplicationExtension()); $container->compile(); return $container; }
55. Kernel public function boot() { if (file_exists($this->cachedContainerFileName)) { require $this->cachedContainerFileName; $this->container = new ProjectServiceContainer(); } else { $container = $this->buildContainer(); $dumper = new PhpDumper($container); file_put_contents($this->cachedContainerFileName, $dumper->dump()); $this->container = $container; } }
56. Kernel public function boot() { if (file_exists($this->cachedContainerFileName)) { require $this->cachedContainerFileName; $this->container = new ProjectServiceContainer(); } else { $container = $this->buildContainer(); if ('dev' !== $container->getParameter('environment')) { $dumper = new PhpDumper($container); file_put_contents($this->cachedContainerFileName, $dumper->dump()); } $this->container = $container; } }
57. parameters.yml application: database: name: acme-dev username: acme-dev password: S0m3R4nD0mP455 host: localhost port: ~ soap_client: wsdl: https://api.store.local/v1/?wsdl http_auth_username: acme-dev http_auth_password: S0m3R4nD0mP455 username: acme-dev-user api_key: R4nD0mAp1K3y product_hydrator: product_url_snippet: http://store.local/product/{sku} product_image_url: http://store.local/media/catalog/product/uploads/
58. services.xml
59. symfony/console console commands
60. Import Handler class ImportAndPersistActionHandler { /** * @param ProductImporter $importer * @param ProductPersister $persister */ public function __construct(ProductImporter $importer, ProductPersister $persister) { $this->importer = $importer; $this->persister = $persister; } public function importAndPersistProducts() { $productsList = $this->importer->importProducts(); $this->persister->saveAll($productsList); } }
61. Console command class ImportAndPersistCommand extends Command { public function __construct(ImportAndPersistActionHandler $action) { $this->action = $action; parent::__construct(); } protected function configure() { $this->setName('products:import'); } protected function execute(InputInterface $input, OutputInterface $output) { $startTime = microtime(true); $this->action->importAndPersistProducts(); $output->writeln( sprintf("Products import completed in %1.02fs.", microtime(true) - $startTime) ); } }
62. app/console #!/usr/bin/php <?php require_once (__DIR__ . '/../vendor/autoload.php'); use Acme\Application\Kernel; use Symfony\Component\Console\Application; $kernel = new Kernel(); $kernel->boot(); $application = new Application(); $application->addCommands([ $kernel->getContainer()->get('acme.command.import_products'), $kernel->getContainer()->get('acme.command.delete_products'), $kernel->getContainer()->get('acme.command.depot_locate'), ]); $application->run();
63. symfony/filesystem persisting products
64. XML Writer class ProductXmlWriter implements ProductPersister { /** * @param Filesystem $filesystem * @param string $fileName */ public function __construct(Filesystem $filesystem, string $fileName) { $this->filesystem = $filesystem; $this->fileName = $fileName; } /** * @param ProductList $productList */ public function saveAll(ProductList $productList) { $this->filesystem->dumpFile($this->fileName, $this->renderXml($productList)); } }
65. Why write XML? - fetching data from Magento and dumping it into xml file is quick - xml can be imported by Drupal’s feed importer
66. Why it didn’t work? - Feed importer was damn slow - 10k products imported in 4.5h - Scheduling import with Elysia Cron module was flaky - Scheduled feed importer would add products all over again - resources hungry!
67. Direct save to the db class DatabaseProductPersister implements ProductPersister { private $repository; /** * @param ProductRepository $repository */ public function __construct(ProductRepository $repository) { $this->repository = $repository; } public function saveAll(ProductList $productList) { foreach ($productList as $product) { $this->repository->save($product); } } }
68. Why direct save to the db? - Drupal promises data structure won’t ever change - It’s fast - 40k products in 2 minutes - It works!
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. container.php <?php require_once DRUPAL_ROOT . '/../vendor/autoload.php'; $kernel = new \Acme\Application\Kernel(); $kernel->boot(); variable_set('di_container', = $kernel->getContainer());
71. 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' => $conf['di_container']->getParameter('database.port'), 'driver' => 'mysql', 'prefix' => '', ], ], ];
72. settings.php <?php ... include_once 'config/container.php'; include 'database.php'; ...
73. depot_locator.module function get_depot_json($postcode) { global $conf; $depotEntity = variable_get('di_container') ->get('acme.depot_locator')->locateDepot($postcode); $depot = $depotEntity->toArray(); set_depot_cookies($depot); return ['depot' => $depot]; }
74. Project folder structure
76. (to get Drupal 7 working with Symfony components) That’s it!
77. What we’ve learnt?
78. as a CMS platform Drupal is great!
79. Cherry pick what you need! Symfony Components
80. Try it yourself! Decoupled code
81. Right tool Choose wisely!
82. Questions?
83. Thank you! https://speakerdeck.com/super_marek @super_marek