Mission (Im)possible: Quality Decoupled Code with Drupal 7 (DrupalCamp Scotland)

We're all excited about Drupal 8 coming up soon and we want to be ready for it! How can we make sure our code is ready for it? How can we build modules that are backwards compatible with D7 and future proofed for D8?

Learn how to build code decoupled from your platform and use it with Drupal or any other framework.

Transcript

1. Marek Matulka
   

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2. at
   @super_marek
   

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

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

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11. How do we learn?
    

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12. Stakeholders
    

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

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14. Vocabulary
    

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15. Ubiquitous Language
    Ubiquitous
    Language
    

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16. Ubiquitous Language
    Ubiquitous
    Language
    Domain
    Expert
    Analyst
    Tester Developer
    Developer
    

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

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18. Example?
    

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19. 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
    

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20. 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
    

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

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

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23. why interface?
    

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

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25. Dependency Inversion
    Policy Layer
    
    Policy Service
    Mechanism
    Layer
    
    Mechanism
    Service
    Utility Layer
    

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26. Layered Architecture
    User Interface
    Application
    Domain
    Infrastructure
    

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27. Layered Architecture
    User Interface
    Application
    Domain
    Infrastructure
    

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28. Clean Architecture
    Entities
    Use Cases
    Controllers
    Web
    

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

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

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

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

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33. Why clean architecture?
    

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34. Why clean architecture?
    - your code is clean(er)
    - decoupled from framework
    - reusable
    - easy to test
    - easy to maintain
    - easy to change
    

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37. symfony/dependency-injection
    symfony/config
    dependency injection
    

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

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

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40. Kernel
    public function boot()
    {
    $this->container = new ContainerBuilder();
    $loader = new YamlFileLoader($this->container, new FileLocator('app/config'));
    $loader->load('parameters.yml');
    $this->container->compile();
    }
    

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41. 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();
    }
    

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42. 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();
    }
    

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43. 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;
    }
    

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44. 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;
    }
    }
    

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45. 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;
    }
    }
    

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46. 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/
    

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47. services.xml
    

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48. symfony/console
    console commands
    

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49. 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);
    }
    }
    

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50. 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)
    );
    }
    }
    

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51. app/console
    #!/usr/bin/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();
    

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52. symfony/filesystem
    persisting products
    

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53. 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));
    }
    }
    

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

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55. 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!
    

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56. 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);
    }
    }
    }
    

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

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58. 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"
    },
    

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59. container.php
    require_once DRUPAL_ROOT . '/../vendor/autoload.php';
    $kernel = new \Acme\Application\Kernel();
    $kernel->boot();
    variable_set('di_container', = $kernel->getContainer());
    

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60. 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' => '',
    ],
    ],
    ];
    

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61. settings.php
    ...
    include_once 'config/container.php';
    include 'database.php';
    ...
    

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62. 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];
    }
    

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63. Project folder structure
    

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66. as a CMS platform
    Drupal is great!
    

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67. Cherry pick what you need!
    Symfony Components
    

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68. Try it yourself!
    Decoupled code
    

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69. Right tool
    Choose wisely!
    

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71. https://speakerdeck.com/super_marek
    @super_marek
    

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