devanych/di-container

Simple implementation of a PSR-11 dependency injection container

2.1.5 2020-12-12 18:28 UTC

This package is auto-updated.

Last update: 2021-11-20 21:15:46 UTC


README

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A simple and lightweight container for dependency injection using autowiring that implements PSR-11 Container.

Support:

  • Objects or class names.

  • Anonymous functions (Closure instance).

  • Scalars (integer, float, string, boolean).

  • Arrays and nested arrays with all of the above data types.

A guide with a detailed description in Russian language is available here.

Installation

This package requires PHP version 7.4 or later.

composer require devanych/di-container

Usage

Create a container:

use Devanych\Di\Container;

$container = new Container();
// or with definitions array
$container = new Container($definitions);

Sets in the container:

/**
 * Sets definition to the container.
 *
 * @param string $id
 * @param mixed $definition
 */
$container->set($id, $definition);

/**
 * Sets multiple definitions at once; used in the constructor.
 *
 * @param array<string, mixed> $definitions
 */
$container->setMultiple($definitions);

Existence in the container:

/**
 * Returns 'true` if the dependency with this ID was sets, otherwise `false`.
 *
 * @param string $id
 * @return bool
 */
$container->has($id);

Gets from the container:

/**
 * Gets instance by definition from the container by ID.
 *
 * @param string $id
 * @return mixed
 * @throws Devanych\Di\Exception\NotFoundException If not found definition in the container.
 * @throws Devanych\Di\Exception\ContainerException If unable to create instance.
 */
$container->get($id);

/**
 * Always gets a new instance by definition from the container by ID.
 *
 * @param string $id
 * @return mixed
 * @throws Devanych\Di\Exception\NotFoundException If not found definition in the container.
 * @throws Devanych\Di\Exception\ContainerException If unable to create instance.
 */
$container->getNew($id);

/**
 * Gets original definition from the container by ID.
 *
 * @param string $id
 * @return mixed
 * @throws Devanych\Di\Exception\NotFoundException If not found definition in the container.
 */
$container->getDefinition($id);

If the definition is an anonymous function or class name, the get() method will execute the function and create an instance of the class only the first time, and subsequent get() calls will return the result already created.

If you need to execute a function and create an instance of the class every time, use the getNew () method.

If the definition is a class name and there are dependencies in its constructor, then when calling the get() and getNew () methods, at the time of creating the class instance, the container will recursively bypass all dependencies and try to resolve them.

If the passed parameter $id to the methods get() and getNew() is a class name and has not been set previously by the set() method, an object of these class will still be created as if it had been set.

If $id is not a class name and has not been set previously by the set() method, the exception Devanych\Di\Exception\NotFoundException will be thrown.

Examples of use

Simple usage:

// Set string
$container->set('string', 'value');
$container->get('string'); // 'value'

// Set integer
$container->set('integer', 5);
$container->get('integer'); // 5

// Set array
$container->set('array', [1,2,3]);
$container->get('array'); // [1,2,3]

// Set nested array
$container->set('nested', [
    'scalar' => [
        'integer' => 5,
        'float' => 3.7,
        'boolean' => false,
        'string' => 'string',
    ],
    'not_scalar' => [
        'closure' => fn() => null,
        'object' => new User(),
        'array' => ['array'],
    ],
]);

// Set object
$container->set('user', fn() => new User());
$container->get('user'); // User instance
// Or
$container->set('user', User::class);
$container->get('user');
// Or
$container->set(User::class, User::class);
$container->get(User::class);
// Or without setting via `set()`
$container->get(User::class);

Usage of dependencies:

/*
final class UserProfile
{
    private $name;
    private $age;

    public function __construct(string $name = 'John', int $age = 25)
    {
        $this->name = $name;
        $this->age = $age;
    }
}

final class User
{
    private $profile;

    public function __construct(UserProfile $profile)
    {
        $this->profile = $profile;
    }
}
*/

$container->set('user_name', 'Alexander');
$container->set('user_age', 40);

$container->set('user', function (\Psr\Container\ContainerInterface $container): User {
    $name = $container->get('user_name');
    $age = $container->get('user_age');
    $profile = new UserProfile($name, $age);
    return new User($profile);
});

$container->get('user');

// Or

$container->set(UserProfile::class, function (\Psr\Container\ContainerInterface $container): UserProfile {
    return new UserProfile($container->get('user_name'), $container->get('user_age'));
});

$container->get(User::class);

// Or with default values (`John` and `25`)

$container->get(User::class);

Usage with dependencies and factories:

/*
final class UserProfileFactory implements \Devanych\Di\FactoryInterface
{
    public function create(\Psr\Container\ContainerInterface $container): UserProfile
    {
        return new UserProfile($container->get('user_name'), $container->get('user_age'));
    }
}
*/

$container->setMultiple([
    UserProfile::class => UserProfileFactory::class,
    // Or without autowiring
    // UserProfile::class => fn => UserProfileFactory(),
    // UserProfile::class => new UserProfileFactory(),
    'user_name' => 'Alexander',
    'user_age' => 40,
]);

$container->get(User::class); // User instance
$container->get(UserProfile::class); // UserProfile instance