DependencyInjectionコンテナ

$ composer require symfony/dependency-injection

<?php
use Symfony\Component\DependencyInjection\ContainerBuilder;

$container = new ContainerBuilder();

// Register a service:
$container->register("logger", \App\Logger::class);

<?php
$container->register("mailer", \App\Mailer::class)
    ->addArgument("smtp.example.com")
    ->addArgument(587);

<?php
use Symfony\Component\DependencyInjection\Reference;

$container->register("email_service", \App\EmailService::class)
    ->addArgument(new Reference("mailer"))
    ->addArgument(new Reference("logger"));

<?php
$emailService = $container->get("email_service");
$emailService->send("user@example.com", "Welcome!");

<?php
$container->register(EmailService::class)
    ->setAutowired(true);
// Constructor is: public function __construct(Mailer $mailer, Logger $logger)

<?php
$container->setParameter("mailer.host", "smtp.example.com");
$container->setParameter("mailer.port", 587);

// Reference in service definition:
$container->register("mailer", Mailer::class)
    ->addArgument("%mailer.host%")
    ->addArgument("%mailer.port%");

# services.yaml
services:
    App\Mailer:
        arguments:
            - "%mailer.host%"
            - "%mailer.port%"

<?php
$container->compile();
// Dump to PHP cache file:
$dumper = new PhpDumper($container);
file_put_contents("CachedContainer.php", $dumper->dump());