ProviderRepository.php

TLDR

The ProviderRepository.php file in the Illuminate\Foundation namespace contains the ProviderRepository class. This class is responsible for registering service providers in an application. It loads a manifest file that contains information on all the service providers registered with the application and their services. The class also allows for deferred loading of service providers based on events.

Methods

__construct

This method is the constructor of the ProviderRepository class. It takes three parameters: the application instance, the filesystem instance, and the path to the manifest file. It initializes the corresponding class properties with the provided values.

load

This method is responsible for registering the application service providers. It takes an array of provider class names as a parameter. First, it loads the manifest file and checks if it needs to be recompiled based on the provided providers. Then, it registers the service providers for each event specified in the manifest. Finally, it registers all eagerly loaded providers with the application and adds deferred services to the application.

loadManifest

This method loads the manifest file that contains a JSON representation of every service provided by the application. If the manifest file exists and is valid, it returns an array representation of the manifest.

shouldRecompile

This method determines if the manifest should be recompiled. It compares the manifest data with the provided providers and returns true if the manifest is null or the providers have changed.

registerLoadEvents

This method registers the load events for a given service provider. It takes the provider class name and an array of events as parameters. If there are events defined, it listens to them and registers the provider with the application when the events occur.

compileManifest

This method compiles the application service manifest file. It takes an array of provider class names as a parameter. It creates a fresh manifest data structure and loops through each provider. If the provider is deferred, it adds its provided services to the manifest, notes the provider, and adds the provider to the "when" array. If the provider is not deferred, it adds it to the "eager" array. It returns the compiled manifest.

freshManifest

This method creates a fresh service manifest data structure. It takes an array of provider class names as a parameter and returns an array containing the providers, eager-loaded providers, and deferred providers.

writeManifest

This method writes the service manifest file to disk. It takes the manifest array as a parameter. It checks if the directory is writable and then replaces the existing manifest file with the updated manifest.

createProvider

This method creates a new provider instance. It takes the provider class name as a parameter and returns an instance of that provider class.

Classes

There are no additional classes in this file.

<?php

namespace Illuminate\Foundation;

use Exception;
use Illuminate\Contracts\Foundation\Application as ApplicationContract;
use Illuminate\Filesystem\Filesystem;

class ProviderRepository
{
    /**
     * The application implementation.
     *
     * @var \Illuminate\Contracts\Foundation\Application
     */
    protected $app;

    /**
     * The filesystem instance.
     *
     * @var \Illuminate\Filesystem\Filesystem
     */
    protected $files;

    /**
     * The path to the manifest file.
     *
     * @var string
     */
    protected $manifestPath;

    /**
     * Create a new service repository instance.
     *
     * @param  \Illuminate\Contracts\Foundation\Application  $app
     * @param  \Illuminate\Filesystem\Filesystem  $files
     * @param  string  $manifestPath
     * @return void
     */
    public function __construct(ApplicationContract $app, Filesystem $files, $manifestPath)
    {
        $this->app = $app;
        $this->files = $files;
        $this->manifestPath = $manifestPath;
    }

    /**
     * Register the application service providers.
     *
     * @param  array  $providers
     * @return void
     */
    public function load(array $providers)
    {
        $manifest = $this->loadManifest();

        // First we will load the service manifest, which contains information on all
        // service providers registered with the application and which services it
        // provides. This is used to know which services are "deferred" loaders.
        if ($this->shouldRecompile($manifest, $providers)) {
            $manifest = $this->compileManifest($providers);
        }

        // Next, we will register events to load the providers for each of the events
        // that it has requested. This allows the service provider to defer itself
        // while still getting automatically loaded when a certain event occurs.
        foreach ($manifest['when'] as $provider => $events) {
            $this->registerLoadEvents($provider, $events);
        }

        // We will go ahead and register all of the eagerly loaded providers with the
        // application so their services can be registered with the application as
        // a provided service. Then we will set the deferred service list on it.
        foreach ($manifest['eager'] as $provider) {
            $this->app->register($provider);
        }

        $this->app->addDeferredServices($manifest['deferred']);
    }

    /**
     * Load the service provider manifest JSON file.
     *
     * @return array|null
     */
    public function loadManifest()
    {
        // The service manifest is a file containing a JSON representation of every
        // service provided by the application and whether its provider is using
        // deferred loading or should be eagerly loaded on each request to us.
        if ($this->files->exists($this->manifestPath)) {
            $manifest = $this->files->getRequire($this->manifestPath);

            if ($manifest) {
                return array_merge(['when' => []], $manifest);
            }
        }
    }

    /**
     * Determine if the manifest should be compiled.
     *
     * @param  array  $manifest
     * @param  array  $providers
     * @return bool
     */
    public function shouldRecompile($manifest, $providers)
    {
        return is_null($manifest) || $manifest['providers'] != $providers;
    }

    /**
     * Register the load events for the given provider.
     *
     * @param  string  $provider
     * @param  array  $events
     * @return void
     */
    protected function registerLoadEvents($provider, array $events)
    {
        if (count($events) < 1) {
            return;
        }

        $this->app->make('events')->listen($events, fn () => $this->app->register($provider));
    }

    /**
     * Compile the application service manifest file.
     *
     * @param  array  $providers
     * @return array
     */
    protected function compileManifest($providers)
    {
        // The service manifest should contain a list of all of the providers for
        // the application so we can compare it on each request to the service
        // and determine if the manifest should be recompiled or is current.
        $manifest = $this->freshManifest($providers);

        foreach ($providers as $provider) {
            $instance = $this->createProvider($provider);

            // When recompiling the service manifest, we will spin through each of the
            // providers and check if it's a deferred provider or not. If so we'll
            // add it's provided services to the manifest and note the provider.
            if ($instance->isDeferred()) {
                foreach ($instance->provides() as $service) {
                    $manifest['deferred'][$service] = $provider;
                }

                $manifest['when'][$provider] = $instance->when();
            }

            // If the service providers are not deferred, we will simply add it to an
            // array of eagerly loaded providers that will get registered on every
            // request to this application instead of "lazy" loading every time.
            else {
                $manifest['eager'][] = $provider;
            }
        }

        return $this->writeManifest($manifest);
    }

    /**
     * Create a fresh service manifest data structure.
     *
     * @param  array  $providers
     * @return array
     */
    protected function freshManifest(array $providers)
    {
        return ['providers' => $providers, 'eager' => [], 'deferred' => []];
    }

    /**
     * Write the service manifest file to disk.
     *
     * @param  array  $manifest
     * @return array
     *
     * @throws \Exception
     */
    public function writeManifest($manifest)
    {
        if (! is_writable($dirname = dirname($this->manifestPath))) {
            throw new Exception("The {$dirname} directory must be present and writable.");
        }

        $this->files->replace(
            $this->manifestPath, '<?php return '.var_export($manifest, true).';'
        );

        return array_merge(['when' => []], $manifest);
    }

    /**
     * Create a new provider instance.
     *
     * @param  string  $provider
     * @return \Illuminate\Support\ServiceProvider
     */
    public function createProvider($provider)
    {
        return new $provider($this->app);
    }
}