selective/container

Description

A PSR-11 container implementation with optional autowiring.

Requirements

• PHP 8.1+

Installation

composer require selective/container

Usage

use Selective\Container\Container;

$container = new Container();
// ...

$myService = $container->get(MyService::class);

Enable Autowiring

The container is able to automatically create and inject dependencies for you. This is called "autowiring".

To enable autowiring you have to add the ConstructorResolver:

<?php

use Selective\Container\Container;
use Selective\Container\Resolver\ConstructorResolver;

$container = new Container();

// Enable autowiring
$container->addResolver(new ConstructorResolver($container));

//...

Defining DI Container Definitions

You can use a factories (closures) to define injections.

<?php

use App\Service\MyService;
use Selective\Container\Container;
use Psr\Container\ContainerInterface;
use Psr\Log\LoggerInterface;

$container = new Container();

// Add definition
$container->factory(MyService::class, function (ContainerInterface $container) {
    return new MyService();
});

Defining Multiple DI Container Definitions

use Psr\Container\ContainerInterface;
// ...

$entries = [
    MyService::class => function (ContainerInterface $container) {
        return new MyService();
    },
    
    PDO::class => function (ContainerInterface $container) {
        return new PDO('sqlite:example.db');
    },
    
    // and so on...
];

$container->factories($entries);

Service Providers

Service providers give the benefit of organising your container definitions along with an increase in performance for larger applications as definitions registered within a service provider are lazily registered at the point where a service is retrieved.

To build a service provider create a invokable class and return the definitions (factories) you would like to register.

<?php

use App\Service\MyService;
use Selective\Container\Container;
use Psr\Container\ContainerInterface;
use Psr\Log\LoggerInterface;

final class MyServiceFactoryProvider
{
    /**
     * @return array<string, callable>
     */
    public function __invoke(): array
    {
        return [
            MyService::class => function (ContainerInterface $container) {
                return new MyService($container->get(LoggerInterface::class));
            },
        ];
    }
}

$container->factories((new MyServiceFactoryProvider())());

Set definitions directly

In addition to defining entries in an array of factories / callbacks, you can also set the value directly as shown below:

$container->set(\App\Domain\MyService::class, new \App\Domain\MyService());

Fetching DI container entries

To fetch a value use the get method:

$pdo = $container->get(PDO::class);

Testing

• Make sure that your container will be recreated for each test. You may use the phpunit setUp() method to initialize the container definitions.
• You can use the set() method to overwrite existing container entries.

Mocking

The set method can also be used to set mocked objects directly into the container.

This example requires phpunit:

<?php

$class = \App\Domain\User\Repository\UserRepository::class;

$mock = $this->getMockBuilder($class)
    ->disableOriginalConstructor()
    ->getMock();

$mock->method('methodToMock1')->willReturn('foo');
$mock->method('methodToMock2')->willReturn('bar');

$container->set($class, $mock);

Slim 4 integration

Example to boostrap a Slim 4 application using the container:

<?php

use Selective\Container\Container;
use Selective\Container\Resolver\ConstructorResolver;
use Slim\App;
use Slim\Factory\AppFactory;

require_once __DIR__ . '/../vendor/autoload.php';

$container = new Container();

// Enable autowiring
$container->addResolver(new ConstructorResolver($container));

// Load container definitions
$container->factories(require __DIR__ . '/container.php');

// Create slim app instance
AppFactory::setContainer($container);
$app = AppFactory::create();

// Add routes, middleware etc...

$app->run();

The container.php file must return an array of factories (closures):

<?php

use Monolog\Logger;
use Psr\Container\ContainerInterface;
use Psr\Log\LoggerInterface;

return [
    'settings' => function () {
        return require __DIR__ . '/settings.php';
    },

    LoggerInterface::class => function (ContainerInterface $container) {
        $logger = new Logger('name');
        
        // ...
        
        return $logger;
    },
    
    // Add more definitions here...
]

PhpStorm Integration

If you use PhpStorm, then create a new file .phpstorm.meta.php in your project root directory and copy/paste the following content:

<?php

namespace PHPSTORM_META;

override(\Psr\Container\ContainerInterface::get(0), map(['' => '@']));

Performance Comparison

selective/container is about:

• 11% faster then php-di/php-di.
• 5.4% faster then league/container.

All tests where made with enabled autowiring.

Migrating from PHP-DI

This PSR-11 container implementation mimics the behavior of PHP-DI.

If you already use factories for your container definitions, the switch should be very simple.

Replace this:

<?php
use DI\ContainerBuilder;

// ...

$containerBuilder = new ContainerBuilder();

$containerBuilder->addDefinitions(__DIR__ . '/container.php');

$container = $containerBuilder->build();

... with this:

<?php
use Selective\Container\Container;
use Selective\Container\Resolver\ConstructorResolver;
// ...

$container = new Container();

// Enable auto-wiring
$container->addResolver(new ConstructorResolver($container));

// Add definitions
$container->factories(require __DIR__ . '/container.php');

That's it.

Credits

• Dominik Zogg (chubbyphp)

Similar libraries

• https://github.com/chubbyphp/chubbyphp-container
• http://php-di.org/
• https://container.thephpleague.com/

License

The MIT License (MIT). Please see License File for more information.