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

Slide 1

Slide 1 text

Applying DDD when building Drupal modules using Symfony components DrupalCamp CS ⚫ Bratislava ⚫ 28 May 2016

Slide 2

Slide 2 text

Who am I?

Slide 3

Slide 3 text

Marek Matulka Technical Team Lead at Inviqa @super_marek

Slide 4

Slide 4 text

No content

Slide 5

Slide 5 text

Background

Slide 6

Slide 6 text

No content

Slide 7

Slide 7 text

Requirement CMS - manage corporate website - manage other brands’ websites - build seasonal microsites - integrate with Magento store

Slide 8

Slide 8 text

No content

Slide 9

Slide 9 text

http://photobucket.com/user/marcrobinsone/media/Drupal%20Comics/marcrobinsonegmailcom__drupalNinja.png.html

Slide 10

Slide 10 text

Why Drupal? - open source CMS - easy to install and manage - most required functionality available out of the box - easy to extend

Slide 11

Slide 11 text

Why Drupal 7?

Slide 12

Slide 12 text

No content

Slide 13

Slide 13 text

No content

Slide 14

Slide 14 text

What is Symfony?

Slide 15

Slide 15 text

is a powerful framework

Slide 16

Slide 16 text

Doctrine ORM Twig

Slide 17

Slide 17 text

set of decoupled components

Slide 18

Slide 18 text

No content

Slide 19

Slide 19 text

Domain Driven Design

Slide 20

Slide 20 text

In order to create a good software, you have to know what the software is all about. – Eric Evans

Slide 21

Slide 21 text

How do we learn?

Slide 22

Slide 22 text

Stakeholders

Slide 23

Slide 23 text

Ask for examples... ...write stories!

Slide 24

Slide 24 text

Vocabulary

Slide 25

Slide 25 text

Ubiquitous Language Ubiquitous Language

Slide 26

Slide 26 text

Ubiquitous Language Ubiquitous Language Domain Expert Analyst Tester Developer Developer

Slide 27

Slide 27 text

Ubiquitous Language Ubiquitous Language Domain Expert Analyst Tester Developer Developer Application Code Acceptance Criteria Specs and documentation

Slide 28

Slide 28 text

Example?

Slide 29

Slide 29 text

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

Slide 30

Slide 30 text

Slide 31

Slide 31 text

Domain namespace Acme\Depot; interface DepotLocator { /** * @param string $postcode * * @return Depot */ public function locateDepot($postcode); }

Slide 32

Slide 32 text

Implementation namespace Acme\MagentoAdapter; use Acme\Depot\DepotLocator; class MagentoDepotLocator implements DepotLocator { public function locateDepot($postcode) { return $this->entityMapper->mapDepot( $this->clientAdapter->findDepotByPostcode($postcode) );

Slide 33

Slide 33 text

why interface?

Slide 34

Slide 34 text

Layered Architecture “High level modules should not depend on lower level implementation” – Robert C. Martin User Interface Application Domain Infrastructure

Slide 35

Slide 35 text

Dependency Inversion Policy Layer Policy Service Mechanism Layer Mechanism Service Utility Layer

Slide 36

Slide 36 text

Layered Architecture User Interface Application Domain Infrastructure

Slide 37

Slide 37 text

Layered Architecture User Interface Application Domain Infrastructure

Slide 38

Slide 38 text

Clean Architecture Entities Use Cases Controllers Web

Slide 39

Slide 39 text

Clean Architecture Entities Use Cases Controllers Web Framework Drivers Interface Adapters Application Business Rules Enterprise Business Rules

Slide 40

Slide 40 text

Hexagonal Architecture UI Adapter Log Adapter Data Storage Adapter External Data Adapter Application Domain

Slide 41

Slide 41 text

Hexagonal Architecture Acme\Depot\DepotLocator Acme\MagentoAdapter\MagentoDepotLocator

Slide 42

Slide 42 text

Hexagonal Architecture Acme\Depot\DepotLocator Acme\MagentoAdapter\MagentoDepotLocator port adapter

Slide 43

Slide 43 text

Why clean architecture? - your code is clean - decoupled from framework - re-usable - easy to test - easier to maintain - easier to change

Slide 44

Slide 44 text

No content

Slide 45

Slide 45 text

When to use DDD? - complex domain - access to domain experts - iterative, long term process - OO design

Slide 46

Slide 46 text

When not to use DDD? - simple domain - data centric domains (CRUD, REST) - prototyping

Slide 47

Slide 47 text

Symfony with Drupal 7

Slide 48

Slide 48 text

symfony/dependency-injection symfony/config dependency injection

Slide 49

Slide 49 text

Dependency Injection - a standardised and centralised way of constructing objects in our application

Slide 50

Slide 50 text

Kernel public function boot() { $this->container = new ContainerBuilder(); $this->container->compile(); }

Slide 51

Slide 51 text

Slide 52

Slide 52 text

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(); }

Slide 53

Slide 53 text

Slide 54

Slide 54 text

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; }

Slide 55

Slide 55 text

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; } }

Slide 56

Slide 56 text

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; } }

Slide 57

Slide 57 text

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/

Slide 58

Slide 58 text

services.xml

Slide 59

Slide 59 text

symfony/console console commands

Slide 60

Slide 60 text

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); } }

Slide 61

Slide 61 text

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) ); } }

Slide 62

Slide 62 text

app/console #!/usr/bin/php 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();

Slide 63

Slide 63 text

symfony/filesystem persisting products

Slide 64

Slide 64 text

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)); } }

Slide 65

Slide 65 text

Why write XML? - fetching data from Magento and dumping it into xml file is quick - xml can be imported by Drupal’s feed importer

Slide 66

Slide 66 text

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!

Slide 67

Slide 67 text

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); } } }

Slide 68

Slide 68 text

Why direct save to the db? - Drupal promises data structure won’t ever change - It’s fast - 40k products in 2 minutes - It works!

Slide 69

Slide 69 text

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" },

Slide 70

Slide 70 text

container.php boot(); variable_set('di_container', = $kernel->getContainer());

Slide 71

Slide 71 text

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' => '', ], ], ];

Slide 72

Slide 72 text

settings.php

Slide 73

Slide 73 text

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]; }