lightweight-container

Context

A module should not bundle and duplicate a heavy dependency from the framework used by the PrestaShop Core, we propose to replace module-lib-service-container with a simple service container to provide the following benefits :

• avoid collisions (between modules and with the core);
• avoid deprecation for a wider PHP and PrestaShop versions support;
• no more cache construction phase, providers are written directly using PHP;
• php configuration files instead of yaml;
• lighter-weighted module zip (~400 Ko).

The goal is not to replace the symfony container but to enhance stability and compatibility for the ps_accounts module in single version mode.
Service container should be provided by the Core, and we use it when available (in the ps_accounts case we will start to use symfony controllers for PrestaShop v9 compatibility).

Installation

Configure GitHub repository

"repositories": [
    {
        "type": "vcs",
        "url": "[email protected]:PrestaShopCorp/lightweight-container.git"
    }
],

Install package

  composer require prestashopcorp/lightweight-container:dev-main

Scope dependency

It's highly recommended to scope the library to avoid collision with other modules using it with a different version.

Create a configuration file

// config.php

<?php

return [
    'my_module.a_parameter' => 'my value example',
    'my_module.log_level' => 'ERROR',
];

Instantiate service container in your module

// src/My_module.php

/**
 * @return \PrestaShopCorp\LightweightContainer\ServiceContainer\ServiceContainer
 *
 * @throws Exception
 */
public function getServiceContainer()
{
    if (null === $this->container) {
        $this->container = \PrestaShop\Module\MyModule\ServiceContainer\MyModuleServiceContainer::createInstance(
            __DIR__ . '/config.php'
        );
    }

    return $this->container;
}

/**
 * @param string $serviceName
 *
 * @return mixed
 */
public function getService($serviceName)
{
    return $this->getServiceContainer()->getService($serviceName);
}

Write a service provider

// src/ServiceContainer/Provider

namespace PrestaShop\Module\MyModule\ServiceContainer\Provider;

use PrestaShop\Module\PsAccounts\Service\MyService;
use PrestaShopCorp\LightweightContainer\ServiceContainer\Contract\IServiceProvider;
use PrestaShopCorp\LightweightContainer\ServiceContainer\ServiceContainer;

class SomethingProvider implements IServiceProvider
{
    /**
     * @param ServiceContainer $container
     *
     * @return void
     */
    public function provide(ServiceContainer $container)
    {
        $container->registerProvider(MyService::class, static function () use ($container) {
            return new ServicesBillingClient(
                $container->getParameter('my_module.a_parameter'),
                $container->get(AaService::class),
                $container->get(BbService::class)
            );
        });
    }
}

Register a service provider

You populate directly the provides array of the ServiceContainer class :

// src/ServiceContainer/MyModuleServiceContainer.php

namespace PrestaShop\Module\MyModule\ServiceContainer;

use PrestaShopCorp\LightweightContainer\ServiceContainer\ServiceContainer;

class MyModuleServiceContainer extends ServiceContainer
{
    /**
     * @var string[]
     */
    protected $provides = [
        Provider\SomethingProvider::class,
        // ...
    ];

    /**
     * @return Logger
     */
    public function getLogger()
    {
        if (null === $this->logger) {
            $this->logger = LoggerFactory::create(
                $this->getParameterWithDefault(
                    'ps_accounts.log_level',
                    LoggerFactory::ERROR
                )
            );
        }

        return $this->logger;
    }

Improvements (next steps)

• Unbind early injected logger (make it a normal service with early injection);
• Add an optional metadata parameter to the registerProvider method containing className (in case the key doesn’t match a real class name), singleton (decide whether its a singleton, true by default), etc …