alanvdb/dependency-container

Basic PSR-11 dependency containers

v0.1 2024-08-13 13:05 UTC

Requires

• psr/container: ^2.0

Requires (Dev)

• phpunit/phpunit: ^11.3

MIT

• alanvdb

README

A PHP PSR-11 Dependency Injection System

Overview

This project provides a lightweight dependency injection system for PHP. It includes the following main components:

1. LazyContainer: A container that lazily instantiates services.
2. IterableLazyContainer: An extension of LazyContainer that implements the Iterator interface.
3. ContainerFactory: A factory to create instances of LazyContainer and IterableLazyContainer.

This library is fully compatible with the PSR-11 standard, which defines a common interface for dependency injection containers. This ensures that your dependency injection containers are interoperable with other PSR-11 compliant libraries.

Installation

To install the dependency-container, you can use Composer:

composer require alanvdb/dependency-container

Usage

LazyContainer

The LazyContainer class allows you to register services with a callable that will be invoked only when the service is requested. This provides lazy instantiation of services, which can improve performance by deferring the creation of services until they are actually needed.

Example

use AlanVdb\Dependency\LazyContainer;

$container = new LazyContainer();

$container->add('service1', function() {
    return new Service1();
});

if ($container->has('service1')) {
    $service1 = $container->get('service1');
}

IterableLazyContainer

The IterableLazyContainer extends LazyContainer and implements the Iterator interface, allowing you to iterate over the registered services.

Example

use AlanVdb\Dependency\IterableLazyContainer;

$container = new IterableLazyContainer();

$container->add('service1', function() {
    return new Service1();
});

$container->add('service2', function() {
    return new Service2();
});

foreach ($container as $serviceId => $service) {
    // Process each service
}

ContainerFactory

The ContainerFactory class provides methods to create instances of LazyContainer and IterableLazyContainer.

Example

use AlanVdb\Dependency\Factory\ContainerFactory;

$factory = new ContainerFactory();

$lazyContainer = $factory->createLazyContainer();
$iterableLazyContainer = $factory->createIterableLazyContainer();

PSR-11 Compatibility

This project adheres to the PSR-11 Container Interface, ensuring that the LazyContainer and IterableLazyContainer classes conform to the standard. This allows for seamless integration with other libraries and frameworks that support PSR-11.

Key PSR-11 Methods

LazyContainer and IterableLazyContainer

These classes implement the following PSR-11 methods:

• get(string $id): Retrieves an entry from the container by its identifier.
  • If the identifier is not found, an exception implementing Psr\Container\NotFoundExceptionInterface is thrown.
• has(string $id): bool: Returns true if the container can return an entry for the given identifier.

By adhering to PSR-11, these containers can be used wherever a PSR-11 compliant container is expected.

API Documentation

LazyContainer

Methods

• add(string $id, callable $generator): Adds a new service to the container.

  • string $id: The service identifier.
  • callable $generator: A callable that returns the service instance.

• get(string $id): Retrieves a service from the container.

  • string $id: The service identifier.
  • Returns the service instance.
  • Throws IdNotFoundException if the service identifier is not found.

• has(string $id): bool: Checks if a service identifier exists in the container.

  • string $id: The service identifier.
  • Returns true if the service exists, false otherwise.

IterableLazyContainer

The IterableLazyContainer inherits all methods from LazyContainer and implements additional methods from the Iterator interface:

• current(): Returns the current element.
• key(): Returns the key of the current element.
• next(): Moves forward to the next element.
• rewind(): Rewinds back to the first element.
• valid(): Checks if the current position is valid.

ContainerFactory

Methods

• createLazyContainer(): LazyContainerInterface: Creates a new instance of LazyContainer.
• createIterableLazyContainer(): LazyContainerInterface & Iterator: Creates a new instance of IterableLazyContainer.

Testing

To run the tests, use the following command:

vendor/bin/phpunit

The tests are located in the tests directory and cover the functionality of LazyContainer, IterableLazyContainer, and ContainerFactory.

License

This project is licensed under the MIT License. See the LICENSE file for details.