Flyweight Pattern Generator

Creates Flyweight pattern infrastructure for memory optimization through object sharing.

When to Use

Component Characteristics

Flyweight Interface

• Defines operations
• Accepts extrinsic state as parameters

ConcreteFlyweight

• Stores intrinsic state (shared)
• Immutable
• Reusable across contexts

FlyweightFactory

• Creates and manages flyweights
• Returns existing or new flyweight
• Ensures sharing

Generation Process

Step 1: Generate Flyweight Interface

Path: src/Domain/{BoundedContext}/

1. {Name}Interface.php — Operations contract

Step 2: Generate ConcreteFlyweight

Path: src/Domain/{BoundedContext}/

1. {Name}Flyweight.php — Shared object

Step 3: Generate FlyweightFactory

Path: src/Domain/{BoundedContext}/Factory/ or src/Infrastructure/

1. {Name}FlyweightFactory.php — Manages flyweights

Step 4: Generate Tests

1. {ClassName}Test.php — Flyweight behavior and sharing verification

File Placement

Naming Conventions

Quick Template Reference

Flyweight

final readonly class {Name}Flyweight implements {Name}Interface
{
    public function __construct(
        private string $intrinsicState
    ) {}

    public function {operation}(string $extrinsicState): {returnType}
    {
        return {combine intrinsic and extrinsic state};
    }
}

FlyweightFactory

final class {Name}FlyweightFactory
{
    private array $flyweights = [];

    public function getFlyweight(string $key): {Name}Interface
    {
        if (!isset($this->flyweights[$key])) {
            $this->flyweights[$key] = new {Name}Flyweight($key);
        }

        return $this->flyweights[$key];
    }

    public function getCount(): int
    {
        return count($this->flyweights);
    }
}

Usage Example

$factory = new CurrencyFlyweightFactory();

// Same object returned
$usd1 = $factory->getFlyweight('USD');
$usd2 = $factory->getFlyweight('USD');

assert($usd1 === $usd2); // true

// Format with extrinsic state
$usd1->format(100.50); // "$100.50"

Common Flyweights

Anti-patterns to Avoid

References

For complete PHP templates and examples, see:

• references/templates.md — Flyweight, factory templates
• references/examples.md — Currency, icon, tax rule flyweights with unit tests