### Retrieve a Service from the Container

Source: https://symfony.com/doc/current/components/dependency_injection.html

Example of how to get the 'newsletter_manager' service instance from the container.

```php
use Symfony\Component\DependencyInjection\ContainerBuilder;

$container = new ContainerBuilder();

// ...

$newsletterManager = $container->get('newsletter_manager');
```

--------------------------------

### Define Services in YAML Configuration

Source: https://symfony.com/doc/current/components/dependency_injection.html

Example of defining services, including parameters and service definitions with constructor arguments and method calls, using YAML format.

```yaml
# config/services.yaml
parameters:
    # ...
    mailer.transport: sendmail

services:
    mailer:
        class:     Mailer
        arguments: ['%mailer.transport%']
    newsletter_manager:
        class:     NewsletterManager
        calls:
            - [setMailer, ['@mailer']]
```

--------------------------------

### Define Services in PHP Configuration

Source: https://symfony.com/doc/current/components/dependency_injection.html

Example of defining services using a PHP configuration file, including parameters and service definitions with constructor arguments and method calls.

```php
// config/services.php
namespace Symfony\Component\DependencyInjection\Loader\Configurator;

use App\Mailer;
use App\NewsletterManager;

return App::config([
    'parameters' => [
        // ...
        'mailer.transport' => 'sendmail',
    ],
    'services' => [
        'mailer' => [
            'class' => Mailer::class,
            'arguments' => [param('mailer.transport')],
        ],
        'newsletter_manager' => [
            'class' => NewsletterManager::class,
            'calls' => [
                'setMailer' => [service('mailer')],
            ],
        ],
    ],
]);
```

--------------------------------

### Install the DependencyInjection Component

Source: https://symfony.com/doc/current/components/dependency_injection.html

Use Composer to install the symfony/dependency-injection component. If using outside a Symfony application, ensure `vendor/autoload.php` is required.

```bash
$ composer require symfony/dependency-injection
```

--------------------------------

### Load Services from PHP Configuration File

Source: https://symfony.com/doc/current/components/dependency_injection.html

Shows how to load service definitions from a PHP configuration file using PhpFileLoader. Ensure the Config component is installed.

```php
use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\PhpFileLoader;

$container = new ContainerBuilder();
$loader = new PhpFileLoader($container, new FileLocator(__DIR__));
$loader->load('services.php');
```

--------------------------------

### Define a Service Class

Source: https://symfony.com/doc/current/components/dependency_injection.html

Example of a simple Mailer class that can be registered as a service.

```php
class Mailer
{
    private string $transport;

    public function __construct()
    {
        $this->transport = 'sendmail';
    }

    // ...
}
```

--------------------------------

### Load Services from YAML Configuration File

Source: https://symfony.com/doc/current/components/dependency_injection.html

Demonstrates loading service definitions from a YAML configuration file using YamlFileLoader. The Yaml component must be installed.

```php
use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;

$container = new ContainerBuilder();
$loader = new YamlFileLoader($container, new FileLocator(__DIR__));
$loader->load('services.yaml');
```

--------------------------------

### Get Service with Exception Handling

Source: https://symfony.com/doc/current/components/dependency_injection.html

Demonstrates how to retrieve a service from the container and specify the behavior when the service does not exist. The second argument is optional and defines the error handling strategy.

```php
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\ContainerInterface;

$containerBuilder = new ContainerBuilder();

// ...

// the second argument is optional and defines what to do when the service doesn't exist
$newsletterManager = $containerBuilder->get('newsletter_manager', ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE);
```

--------------------------------

### Define Service for Setter Injection

Source: https://symfony.com/doc/current/components/dependency_injection.html

Example of a NewsletterManager class designed for setter injection of the Mailer service.

```php
class NewsletterManager
{
    private \Mailer $mailer;

    public function setMailer(\Mailer $mailer): void
    {
        $this->mailer = $mailer;
    }

    // ...
}
```

--------------------------------

### Define a Dependent Service Class

Source: https://symfony.com/doc/current/components/dependency_injection.html

Example of a NewsletterManager class that depends on the Mailer service.

```php
class NewsletterManager
{
    public function __construct(
        private \Mailer $mailer,
    ) {
    }

    // ...
}
```

--------------------------------

### Register Service with Constructor Argument

Source: https://symfony.com/doc/current/components/dependency_injection.html

Registering the Mailer service and providing the transport argument directly.

```php
use Symfony\Component\DependencyInjection\ContainerBuilder;

$container = new ContainerBuilder();
$container
    ->register('mailer', 'Mailer')
    ->addArgument('sendmail');
```

--------------------------------

### Use Container Parameters for Service Configuration

Source: https://symfony.com/doc/current/components/dependency_injection.html

Define a parameter for the mail transport and use it in the service registration.

```php
use Symfony\Component\DependencyInjection\ContainerBuilder;

$container = new ContainerBuilder();
$container->setParameter('mailer.transport', 'sendmail');
$container
    ->register('mailer', 'Mailer')
    ->addArgument('%mailer.transport%');
```

--------------------------------

### Define a Service with Constructor Arguments

Source: https://symfony.com/doc/current/components/dependency_injection.html

Modify the Mailer class to accept the transport as a constructor argument for flexibility.

```php
class Mailer
{
    public function __construct(
        private string $transport,
    ) {
    }

    // ...
}
```

--------------------------------

### Inject Service Dependency via Constructor

Source: https://symfony.com/doc/current/components/dependency_injection.html

Registering the NewsletterManager and injecting the 'mailer' service using a Reference.

```php
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Reference;

$container = new ContainerBuilder();

$container->setParameter('mailer.transport', 'sendmail');
$container
    ->register('mailer', 'Mailer')
    ->addArgument('%mailer.transport%');

$container
    ->register('newsletter_manager', 'NewsletterManager')
    ->addArgument(new Reference('mailer'));
```

--------------------------------

### Register a Service in the Container

Source: https://symfony.com/doc/current/components/dependency_injection.html

Registering the Mailer class as a service named 'mailer' in the ContainerBuilder.

```php
use Symfony\Component\DependencyInjection\ContainerBuilder;

$container = new ContainerBuilder();
$container->register('mailer', 'Mailer');
```

--------------------------------

### Inject Service Dependency via Setter Method

Source: https://symfony.com/doc/current/components/dependency_injection.html

Registering the NewsletterManager and injecting the 'mailer' service using a method call.

```php
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Reference;

$container = new ContainerBuilder();

$container->setParameter('mailer.transport', 'sendmail');
$container
    ->register('mailer', 'Mailer')
    ->addArgument('%mailer.transport%');

$container
    ->register('newsletter_manager', 'NewsletterManager')
    ->addMethodCall('setMailer', [new Reference('mailer')]);
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.