php-di.md

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php-di

The PHP-DI edition

As explained in the dependency injection documentation, Silly can work with any dependency injection container.

However in order to provide an easy way to get started we provide a "PHP-DI edition" that is already configured with the PHP-DI container.

Installation

$ composer require mnapoli/silly-php-di

Usage

Simply use the alternative Application class offered by the PHP-DI bridge:

// Replace this
$app = new Silly\Application();

// with this:
$app = new Silly\Edition\PhpDi\Application();

Thanks to PHP-DI's autowiring capabilities you can define your commands in classes:

use Symfony\Component\Console\Output\OutputInterface;

class MyCommand
{
    public function __invoke($name, OutputInterface $output)
    {
        if ($name) {
            $text = 'Hello, '.$name;
        } else {
            $text = 'Hello';
        }

        $output->writeln($text);
    }
}

$app = new Silly\Edition\PhpDi\Application();

$app->command('greet [name]', 'MyCommand');

$app->run();

PHP-DI will automatically create a new instance of MyCommand when the greet command is called.

Configuration

You can configure PHP-DI by overridding the createContainer() method in your Application class:

class MyApplication extends Silly\Edition\PhpDi\Application
{
    protected function createContainer()
    {
        $builder = ContainerBuilder::buildDevContainer();
        
        $builder->addDefinitions([
            // add your PHP-DI config here
        ]);
        
        return $builder->build(); // return the customized container
    }
}

// In your main file you can now use your custom application class:
$app = new MyApplication();

If you do not want to go through the trouble of creating a new class, you can use PHP 7's anonymous classes:

$app = new class() extends Silly\Edition\PhpDi\Application
{
    protected function createContainer()
    {
        $builder = ContainerBuilder::buildDevContainer();
        
        $builder->addDefinitions([
            // add your PHP-DI config here
        ]);
        
        return $builder->build(); // return the customized container
    }
};

Dependency injection in parameters

You can also use dependency injection in parameters:

use Psr\Logger\LoggerInterface;

// ...

$container = $app->getContainer();

$container->set('dbHost', 'localhost');
// Monolog's configuration is voluntarily skipped
$container->set(LoggerInterface::class, DI\object('Monolog\Logger'));

$app->command('greet [name]', function ($name, $dbHost, LoggerInterface $logger) {
    // ...
});

$app->run();

Dependency injection in parameters follows the precedence rules explained in the dependency injection documentation:

• command parameters are matched in priority using the parameter names ($name)
• then container entries are matched using the callable type-hint (Psr\Logger\LoggerInterface)
• finally container entries are matched using the parameter names ($dbHost)