PHP 패턴 완전 정리

PHP code

<?php
$path = parse_url($_SERVER['REQUEST_URI'] ?? '/', PHP_URL_PATH);

echo match ($path) {
    '/' => 'home',
    '/health' => 'ok',
    default => '404',
};

PHP code

<?php
interface UserRepository {
    public function findById(int $id): ?array;
}

class InMemoryUserRepository implements UserRepository {
    public function __construct(private array $rows) {}
    public function findById(int $id): ?array {
        foreach ($this->rows as $row) {
            if ($row['id'] === $id) return $row;
        }
        return null;
    }
}

var_dump((new InMemoryUserRepository([['id' => 1]]))->findById(1));

PHP code

<?php
class Container {
    private array $factories = [];

    public function set(string $id, callable $factory): void { $this->factories[$id] = $factory; }
    public function get(string $id): mixed { return $this->factories[$id]($this); }
}

$container = new Container();
$container->set('config', fn () => ['env' => 'local']);
print_r($container->get('config'));

PHP code

<?php
$middlewares = [
    fn (array $request, callable $next) => $next($request + ['trace' => 'a']),
    fn (array $request, callable $next) => $next($request + ['auth' => true]),
];

$kernel = array_reduce(
    array_reverse($middlewares),
    fn (callable $next, callable $mw): callable => fn (array $request) => $mw($request, $next),
    fn (array $request): array => $request
);

print_r($kernel(['path' => '/']));

PHP code

<?php
interface DiscountStrategy {
    public function apply(int $price): int;
}

class TenPercent implements DiscountStrategy {
    public function apply(int $price): int { return (int) ($price * 0.9); }
}

echo (new TenPercent())->apply(10000);

PHP code

<?php
interface Notifier {
    public function send(string $message): string;
}

class EmailNotifier implements Notifier {
    public function send(string $message): string { return 'mail:' . $message; }
}

class NotifierFactory {
    public static function make(string $type): Notifier {
        return match ($type) {
            'email' => new EmailNotifier(),
            default => throw new InvalidArgumentException('unsupported'),
        };
    }
}

echo NotifierFactory::make('email')->send('hi');

PHP code

<?php
class QueryBuilder {
    private array $parts = [];

    public function select(string $table): self { $this->parts[] = 'SELECT * FROM ' . $table; return $this; }
    public function where(string $condition): self { $this->parts[] = 'WHERE ' . $condition; return $this; }
    public function toSql(): string { return implode(' ', $this->parts); }
}

echo (new QueryBuilder())->select('users')->where('active = 1')->toSql();

PHP code

<?php
class EventBus {
    private array $listeners = [];

    public function on(string $event, callable $listener): void { $this->listeners[$event][] = $listener; }
    public function emit(string $event, mixed $payload): void {
        foreach ($this->listeners[$event] ?? [] as $listener) {
            $listener($payload);
        }
    }
}

$bus = new EventBus();
$bus->on('user.created', fn (array $user) => print($user['name']));
$bus->emit('user.created', ['name' => 'mida']);

PHP code

<?php
interface Command {
    public function handle(): string;
}

class SendMailCommand implements Command {
    public function handle(): string { return 'sent'; }
}

echo (new SendMailCommand())->handle();

PHP code

<?php
readonly class UserDto {
    public function __construct(public int $id, public string $name) {}
}

function mapUser(array $row): UserDto {
    return new UserDto($row['id'], $row['name']);
}

print_r(mapUser(['id' => 1, 'name' => 'Kim']));

PHP code

<?php
class CreatePost {
    public function __construct(public string $title) {}
}

class FindPostById {
    public function __construct(public int $id) {}
}

echo CreatePost::class . ' / ' . FindPostById::class;

PHP code

<?php
interface ArticleGateway {
    public function latest(): array;
}

class CachedArticleGateway implements ArticleGateway {
    private ?array $cache = null;
    public function __construct(private ArticleGateway $inner) {}
    public function latest(): array {
        return $this->cache ??= $this->inner->latest();
    }
}

echo CachedArticleGateway::class;

PHP code

<?php
interface SmsSender {
    public function send(string $message): string;
}

class LegacySmsClient {
    public function push(string $body): string { return 'legacy:' . $body; }
}

class SmsAdapter implements SmsSender {
    public function __construct(private LegacySmsClient $client) {}
    public function send(string $message): string { return $this->client->push($message); }
}

echo (new SmsAdapter(new LegacySmsClient()))->send('hello');

PHP code

<?php
function render(string $template, array $data): string {
    foreach ($data as $key => $value) {
        $template = str_replace('{{' . $key . '}}', (string) $value, $template);
    }
    return $template;
}

echo render('hello {{name}}', ['name' => 'php']);

PHP code

<?php
spl_autoload_register(function (string $class): void {
    $prefix = 'App\\';
    if (!str_starts_with($class, $prefix)) {
        return;
    }

    $relative = substr($class, strlen($prefix));
    $path = __DIR__ . '/src/' . str_replace('\\', '/', $relative) . '.php';
    if (is_file($path)) {
        require $path;
    }
});

PHP code

<?php
readonly class AppConfig {
    public function __construct(
        public string $env,
        public bool $debug
    ) {}
}

$config = new AppConfig('local', true);
echo $config->env;

PHP code

<?php
function route(string $method, string $path): string {
    return match ([$method, $path]) {
        ['GET', '/users'] => 'list users',
        ['POST', '/users'] => 'create user',
        default => '404',
    };
}

echo route('GET', '/users');

PHP code

<?php
interface PaymentPort {
    public function charge(int $amount): string;
}

class CheckoutService {
    public function __construct(private PaymentPort $payment) {}
    public function checkout(int $amount): string { return $this->payment->charge($amount); }
}

echo CheckoutService::class;