Skip to main content
UploadLanguage (EN)Support
BusinessMobileSocial MediaMarketingTechnologyArt & PhotosCareerDesignEducationPresentations & Public SpeakingGovernment & NonprofitHealthcareInternetLawLeadership & ManagementAutomotiveEngineeringSoftwareRecruiting & HRRetailSalesServicesScienceSmall Business & EntrepreneurshipFoodEnvironmentEconomy & FinanceData & AnalyticsInvestor RelationsSportsSpiritualNews & PoliticsTravelSelf ImprovementReal EstateEntertainment & HumorHealth & MedicineDevices & HardwareLifestyle
Łukasz Chruściel, profile picture
Uploaded byŁukasz Chruściel
348 views

Symfony World - Symfony components and design patterns

The document discusses the use of Symfony components and design patterns, highlighting their benefits in communication, code reduction, increased cohesion, and decreased coupling. It presents a sample project featuring a CheckoutController class, detailing operations like adding or removing products from a cart, applying promotions, and taxation methods. Additionally, it emphasizes principles such as Single Responsibility and Dependency Inversion in enhancing code quality and maintainability.

Software◦
Related topics:
Software Design Patterns•Insights on Software Development•
Download to read offline
Symfony Components and Design Patterns
Design patterns?
Why should you care?
Communication
Communication Reduced amount of code in one chunk
Communication Reduced amount of code in one chunk Increased cohesion and reduced coupling
Communication Reduced amount of code in one chunk Increased cohesion and reduced coupling Extendibility
Communication Reduced amount of code in one chunk Increased cohesion and reduced coupling Extendibility SOLID
Increase code quality
Can we measure it?
Avg. Logic Lines of Code
Avg. Logic Lines of Code LLoC
Avg. Logic Lines of Code LLoC Amount of classes
Avg. Logic Lines of Code LLoC Amount of classes AoC
Avg. Logic Lines of Code LLoC Amount of classes AoC Avg. Cyclomatic Complexity
Avg. Logic Lines of Code LLoC Amount of classes AoC Avg. Cyclomatic Complexity ACC
Let’s see the code
Sample Project
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; }
{ // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct( $options[‘product'], $options[‘type'], $options[‘quantity'], $options[‘price'] ); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository $this->repository[$options['cart_id']] = $cart;
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
Avg. Logic Lines of Code 40 Amount of classes 1 Avg. Cyclomatic Complexity 8
LLoC AoC ACC Sample project 40 1 8
Single responsibility principle Open close principle Liskov substitution principle Interface segregation principle Dependency inversion principle
Single responsibility principle Open close principle Liskov substitution principle Interface segregation principle Dependency inversion principle
Composition
Preparation
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
$cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } // Apply taxation /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion $this->applyPromotion($cart); // Apply taxation $this->applyTaxation($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
private function applyTaxation(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } } private function applyPromotion(Cart $cart): void { if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } }
private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } // Apply promotion $this->applyPromotion($cart); // Apply taxation $this->applyTaxation($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } $this->processOrder($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
private function processOrder(Cart $cart): void { // Apply promotion $this->applyPromotion($cart); // Apply taxation $this->applyTaxation($cart); }
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } $this->processOrder($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } private function applyTaxation(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } } private function applyPromotion(Cart $cart): void { if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } } /** * @param Cart $cart */ private function processOrder(Cart $cart): void { // Apply promotion $this->applyPromotion($cart); // Apply taxation $this->applyTaxation($cart); } }
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } $this->processOrder($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } $this->processOrder($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
Extraction
final class CheckoutController { private array $repository = []; public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } $this->orderProcessor->processOrder($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
final class CompositeOrderProcessor implements OrderProcessor { public function processOrder(Cart $cart): void { // Apply promotion $this->applyPromotion($cart); // Apply taxation $this->applyTaxation($cart); } private function applyTaxation(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } } private function applyPromotion(Cart $cart): void { if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } } }
LLoC AoC ACC Sample project 40 1 8 Extracted processor 61 2 4.5
final class CompositeOrderProcessor implements OrderProcessor { public function processOrder(Cart $cart): void { // Apply promotion $this->applyPromotion($cart); // Apply taxation $this->applyTaxation($cart); } private function applyTaxation(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } } private function applyPromotion(Cart $cart): void { if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } } }
final class CompositeOrderProcessor implements OrderProcessor { public function processOrder(Cart $cart): void { // Apply promotion $this->applyPromotion($cart); // Apply taxation $this->applyTaxation($cart); } private function applyTaxation(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } } private function applyPromotion(Cart $cart): void { if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } } }
final class OrderTaxationProcessor implements OrderProcessor { public function processOrder(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } } }
final class CompositeOrderProcessor implements OrderProcessor { public function processOrder(Cart $cart): void { // Apply promotion $this->applyPromotion($cart); // Apply taxation $this->applyTaxation($cart); } private function applyPromotion(Cart $cart): void { if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } } }
final class OrderPromotionProcessor implements OrderProcessor { public function processOrder(Cart $cart): void { if ($cart->getPrice() >= 1000) { $cart->applyPercentageDiscount(0.1); } } }
final class CompositeOrderProcessor implements OrderProcessor { private OrderPromotionProcessor $orderPromotionProcessor; private OrderTaxationProcessor $orderTaxationProcessor; public function __construct( OrderPromotionProcessor $orderPromotionProcessor, OrderTaxationProcessor $orderTaxationProcessor ) { $this->orderPromotionProcessor = $orderPromotionProcessor; $this->orderTaxationProcessor = $orderTaxationProcessor; } public function processOrder(Cart $cart): void { // Apply promotion $this->orderPromotionProcessor->processOrder($cart); // Apply taxation $this->orderTaxationProcessor->processOrder($cart); } }
LLoC AoC ACC Sample project 40 1 8 Extracted processor 61 2 4.5 Separated processors 76 4 2.75
final class CompositeOrderProcessor implements OrderProcessor { private OrderPromotionProcessor $orderPromotionProcessor; private OrderTaxationProcessor $orderTaxationProcessor; public function __construct( OrderPromotionProcessor $orderPromotionProcessor, OrderTaxationProcessor $orderTaxationProcessor ) { $this->orderPromotionProcessor = $orderPromotionProcessor; $this->orderTaxationProcessor = $orderTaxationProcessor; } public function processOrder(Cart $cart): void { // Apply promotion $this->orderPromotionProcessor->processOrder($cart); // Apply taxation $this->orderTaxationProcessor->processOrder($cart); } }
final class CompositeOrderProcessor implements OrderProcessor { private iterable $orderProcessors; public function __construct( OrderPromotionProcessor $orderPromotionProcessor, OrderTaxationProcessor $orderTaxationProcessor ) { $this->orderProcessors = [ $orderPromotionProcessor, $orderTaxationProcessor ]; } public function processOrder(Cart $cart): void { foreach ($this->orderProcessors as $orderProcessor) { $orderProcessor->processOrder($cart); } } }
final class CompositeOrderProcessor implements OrderProcessor { private iterable $orderProcessors; public function __construct( OrderPromotionProcessor $orderPromotionProcessor, OrderTaxationProcessor $orderTaxationProcessor ) { $this->orderProcessors = [ $orderPromotionProcessor, $orderTaxationProcessor ]; } public function processOrder(Cart $cart): void { foreach ($this->orderProcessors as $orderProcessor) { $orderProcessor->processOrder($cart); } } }
final class CompositeOrderProcessor implements OrderProcessor { private iterable $orderProcessors; public function __construct( OrderPromotionProcessor $orderPromotionProcessor, OrderTaxationProcessor $orderTaxationProcessor ) { $this->orderProcessors = [ $orderPromotionProcessor, $orderTaxationProcessor ]; } public function processOrder(Cart $cart): void { foreach ($this->orderProcessors as $orderProcessor) { $orderProcessor->processOrder($cart); } } }
final class CompositeOrderProcessor implements OrderProcessor { private iterable $orderProcessors; public function __construct( OrderPromotionProcessor $orderPromotionProcessor, OrderTaxationProcessor $orderTaxationProcessor ) { $this->orderProcessors = [ $orderPromotionProcessor, $orderTaxationProcessor ]; } public function processOrder(Cart $cart): void { foreach ($this->orderProcessors as $orderProcessor) { $orderProcessor->processOrder($cart); } } }
final class CompositeOrderProcessor implements OrderProcessor { private iterable $orderProcessors; public function __construct(iterable $orderProcessors) { $this->orderProcessors = $orderProcessors; } public function processOrder(Cart $cart): void { foreach ($this->orderProcessors as $orderProcessor) { $orderProcessor->processOrder($cart); } } }
final class CompositeOrderProcessor implements OrderProcessor { private iterable $orderProcessors; public function __construct(iterable $orderProcessors) { $this->orderProcessors = $orderProcessors; } public function processOrder(Cart $cart): void { foreach ($this->orderProcessors as $orderProcessor) { $orderProcessor->processOrder($cart); } } }
SymfonyDesignPatternsProcessorOrderProcessor: class: 'SymfonyDesignPatternsProcessorCompositeOrderProcessor' arguments: - [ '@SymfonyDesignPatternsProcessorOrderPromotionProcessor', '@SymfonyDesignPatternsProcessorOrderTaxationProcessor' ]
Can Symfony help us with it?
SymfonyDesignPatternsProcessorOrderProcessor: class: 'SymfonyDesignPatternsProcessorCompositeOrderProcessor' arguments: - !tagged_iterator app.order_processor
SymfonyDesignPatternsProcessorOrderProcessor: class: 'SymfonyDesignPatternsProcessorCompositeOrderProcessor' arguments: - !tagged_iterator app.order_processor
SymfonyDesignPatternsProcessorOrderPromotionProcessor: tags: - app.order_processor SymfonyDesignPatternsProcessorOrderTaxationProcessor: tags: - app.order_processor
LLoC AoC ACC Sample project 40 1 8 Extracted processor 61 2 4.5 Separated processors 76 4 2.75 Composite iteration 73 4 3
Single responsibility principle Open close principle Liskov substitution principle Interface segregation principle Dependency inversion principle
LLoC AoC ACC Sample project 40 1 8 Composite iteration 73 4 3
Strategy
final class OrderTaxationProcessor implements OrderProcessor { public function processOrder(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } } }
final class OrderTaxationProcessor implements OrderProcessor { public function processOrder(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } } }
final class OrderTaxationProcessor implements OrderProcessor { private TaxationStrategyDelegator $taxationStrategy; public function __construct(TaxationStrategyDelegator $taxationStrategy) { $this->taxationStrategy = $taxationStrategy; } public function processOrder(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { $this->taxationStrategy->processTaxation($item); } } }
final class OrderTaxationProcessor implements OrderProcessor { private TaxationStrategyDelegator $taxationStrategy; public function __construct(TaxationStrategyDelegator $taxationStrategy) { $this->taxationStrategy = $taxationStrategy; } public function processOrder(Cart $cart): void { /** @var CartItem $item */ foreach ($cart->getItems() as $item) { $this->taxationStrategy->processTaxation($item); } } }
final class TaxationStrategyDelegator implements TaxationStrategy { public function processTaxation(CartItem $item): void { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } }
final class TaxationStrategyDelegator implements TaxationStrategy { public function processTaxation(CartItem $item): void { if ('shirt' === $item->getType()) { $item->setTaxationPercentage(0.23); } if ('book' === $item->getType()) { $item->setTaxationPercentage(0.08); } } }
final class TaxationStrategyDelegator implements TaxationStrategy { private ShirtTaxationStrategy $shirtTaxationStrategy; private BookTaxationStrategy $bookTaxationStrategy; public function __construct( ShirtTaxationStrategy $shirtTaxationStrategy, BookTaxationStrategy $bookTaxationStrategy ) { $this->shirtTaxationStrategy = $shirtTaxationStrategy; $this->bookTaxationStrategy = $bookTaxationStrategy; } public function processTaxation(CartItem $item): void { if ('shirt' === $item->getType()) { $this->shirtTaxationStrategy->processTaxation($item); } if ('book' === $item->getType()) { $this->bookTaxationStrategy->processTaxation($item); } } }
final class TaxationStrategyDelegator implements TaxationStrategy { private ShirtTaxationStrategy $shirtTaxationStrategy; private BookTaxationStrategy $bookTaxationStrategy; public function __construct( ShirtTaxationStrategy $shirtTaxationStrategy, BookTaxationStrategy $bookTaxationStrategy ) { $this->shirtTaxationStrategy = $shirtTaxationStrategy; $this->bookTaxationStrategy = $bookTaxationStrategy; } public function processTaxation(CartItem $item): void { if ('shirt' === $item->getType()) { $this->shirtTaxationStrategy->processTaxation($item); } if ('book' === $item->getType()) { $this->bookTaxationStrategy->processTaxation($item); } } }
final class TaxationStrategyDelegator implements TaxationStrategy { private ShirtTaxationStrategy $shirtTaxationStrategy; private BookTaxationStrategy $bookTaxationStrategy; public function __construct( ShirtTaxationStrategy $shirtTaxationStrategy, BookTaxationStrategy $bookTaxationStrategy ) { $this->shirtTaxationStrategy = $shirtTaxationStrategy; $this->bookTaxationStrategy = $bookTaxationStrategy; } public function processTaxation(CartItem $item): void { if ('shirt' === $item->getType()) { $this->shirtTaxationStrategy->processTaxation($item); } if ('book' === $item->getType()) { $this->bookTaxationStrategy->processTaxation($item); } } }
final class TaxationStrategyDelegator implements TaxationStrategy { private ShirtTaxationStrategy $shirtTaxationStrategy; private BookTaxationStrategy $bookTaxationStrategy; public function __construct( ShirtTaxationStrategy $shirtTaxationStrategy, BookTaxationStrategy $bookTaxationStrategy ) { $this->shirtTaxationStrategy = $shirtTaxationStrategy; $this->bookTaxationStrategy = $bookTaxationStrategy; } public function processTaxation(CartItem $item): void { if ('shirt' === $item->getType()) { $this->shirtTaxationStrategy->processTaxation($item); } if ('book' === $item->getType()) { $this->bookTaxationStrategy->processTaxation($item); } } }
final class TaxationStrategyDelegator implements TaxationStrategy { private array $indexedTaxationStrategies; public function __construct( ShirtTaxationStrategy $shirtTaxationStrategy, BookTaxationStrategy $bookTaxationStrategy ) { $this->indexedTaxationStrategies = [ 'shirt' => $shirtTaxationStrategy, 'book' => $bookTaxationStrategy, ]; } public function processTaxation(CartItem $item): void { $this->indexedTaxationStrategies[$item->getType()]->processTaxation($item); } }
final class TaxationStrategyDelegator implements TaxationStrategy { private array $indexedTaxationStrategies; public function __construct( ShirtTaxationStrategy $shirtTaxationStrategy, BookTaxationStrategy $bookTaxationStrategy ) { $this->indexedTaxationStrategies = [ 'shirt' => $shirtTaxationStrategy, 'book' => $bookTaxationStrategy, ]; } public function processTaxation(CartItem $item): void { $this->indexedTaxationStrategies[$item->getType()]->processTaxation($item); } }
Can Symfony help us with it?
final class TaxationStrategyDelegator implements TaxationStrategy { private array $indexedTaxationStrategies; public function __construct( ShirtTaxationStrategy $shirtTaxationStrategy, BookTaxationStrategy $bookTaxationStrategy ) { $this->indexedTaxationStrategies = [ 'shirt' => $shirtTaxationStrategy, 'book' => $bookTaxationStrategy, ]; } public function processTaxation(CartItem $item): void { $this->indexedTaxationStrategies[$item->getType()]->processTaxation($item); } }
final class TaxationStrategyDelegator implements TaxationStrategy { private array $indexedTaxationStrategies; public function __construct( ShirtTaxationStrategy $shirtTaxationStrategy, BookTaxationStrategy $bookTaxationStrategy ) { $this->indexedTaxationStrategies = [ 'shirt' => $shirtTaxationStrategy, 'book' => $bookTaxationStrategy, ]; } public function processTaxation(CartItem $item): void { $this->indexedTaxationStrategies[$item->getType()]->processTaxation($item); } }
final class TaxationStrategyDelegator implements TaxationStrategy { private ServiceLocator $taxationStrategies; public function __construct(ServiceLocator $taxationStrategies) { $this->taxationStrategies = $taxationStrategies; } public function processTaxation(CartItem $item): void { $this->taxationStrategies->get($item->getType())->processTaxation($item); } }
final class TaxationStrategyDelegator implements TaxationStrategy { private ServiceLocator $taxationStrategies; public function __construct(ServiceLocator $taxationStrategies) { $this->taxationStrategies = $taxationStrategies; } public function processTaxation(CartItem $item): void { $this->taxationStrategies->get($item->getType())->processTaxation($item); } }
SymfonyDesignPatternsTaxationStrategiesTaxationStrategy: class: 'SymfonyDesignPatternsTaxationStrategiesTaxationStrategyDelegator' arguments: - !tagged_locator { tag: 'app.taxation_strategies', index_by: 'type' }
SymfonyDesignPatternsTaxationStrategiesTaxationStrategy: class: 'SymfonyDesignPatternsTaxationStrategiesTaxationStrategyDelegator' arguments: - !tagged_locator { tag: 'app.taxation_strategies', index_by: 'type' }
SymfonyDesignPatternsTaxationStrategiesBookTaxationStrategy: tags: - { name: 'app.taxation_strategies', type: 'book' } SymfonyDesignPatternsTaxationStrategiesShirtTaxationStrategy: tags: - { name: 'app.taxation_strategies', type: 'shirt' }
LLoC AoC ACC Sample project 40 1 8 Composite iteration 73 4 3 Strategy iteration 102 7 1.86
Single responsibility principle Open close principle Liskov substitution principle Interface segregation principle Dependency inversion principle
Time for small refactoring
final class CheckoutController { private array $repository = []; private OrderProcessor $orderProcessor; public function __construct(OrderProcessor $orderProcessor) { $this->orderProcessor = $orderProcessor; } public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } $this->orderProcessor->processOrder($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
final class CheckoutController { private array $repository = []; private OrderProcessor $orderProcessor; public function __construct(OrderProcessor $orderProcessor) { $this->orderProcessor = $orderProcessor; } public function cartAction(string $operation, array $options): Cart { // Fetch object from repository if (isset($this->repository[$options['cart_id']])) { /** @var Cart $cart */ $cart = $this->repository[$options['cart_id']]; } else { $cart = new Cart($options['cart_id']); } // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } $this->orderProcessor->processOrder($cart); // Save into repository $this->repository[$options['cart_id']] = $cart; return $cart; } }
final class CheckoutController { private OrderProcessor $orderProcessor; private CartRepository $cartRepository; public function __construct(OrderProcessor $orderProcessor, CartRepository $cartRepository) { $this->orderProcessor = $orderProcessor; $this->cartRepository = $cartRepository; } public function cartAction(string $operation, array $options): Cart { // Fetch object from repository $cart = $this->cartRepository->getCart($options['cart_id']); // Perform operation if ('add_to_cart' === $operation) { $cart->addProduct($options['product'], $options['type'], $options['quantity'], $options['price']); } elseif ('remove_from_cart' === $operation) { $cart->removeProduct($options['product']); } else { throw new InvalidArgumentException('operation not supported'); } $this->orderProcessor->processOrder($cart); // Save into repository $this->cartRepository->save($cart); return $cart; } }