MultipleInstanceManager.php

TLDR

The MultipleInstanceManager class in the provided file is an abstract class that manages multiple instances of an application. It provides methods for creating and getting instances, as well as registering custom instance creators. The class is meant to be extended and implemented by concrete classes.

Methods

__construct

The constructor of the MultipleInstanceManager class. It accepts an instance of the Application class as a parameter and assigns it to the $app property.

getDefaultInstance

An abstract method that needs to be implemented by concrete classes. It should return the default instance name.

setDefaultInstance

An abstract method that needs to be implemented by concrete classes. It sets the default instance name based on the provided parameter.

getInstanceConfig

An abstract method that needs to be implemented by concrete classes. It returns the instance-specific configuration based on the provided name.

instance

A method that returns an instance based on the provided name. If no name is provided, it uses the default instance name.

get

A protected method that attempts to get an instance from the local cache. If the instance is not found, it resolves it using the resolve method.

resolve

A protected method that resolves the given instance by calling the appropriate driver creator method or a custom creator method.

callCustomCreator

A protected method that calls a custom instance creator based on the provided configuration.

forgetInstance

A method that unsets the given instances from the local cache. If no name is provided, it unsets the default instance.

purge

A method that disconnects the given instance and removes it from the local cache. If no name is provided, it disconnects and removes the default instance.

extend

A method that registers a custom instance creator closure for the given instance name.

__call

A magic method that dynamically calls the default instance's methods and passes any provided parameters to it.

END

<?php

namespace Illuminate\Support;

use Closure;
use InvalidArgumentException;
use RuntimeException;

abstract class MultipleInstanceManager
{
    /**
     * The application instance.
     *
     * @var \Illuminate\Contracts\Foundation\Application
     */
    protected $app;

    /**
     * The array of resolved instances.
     *
     * @var array
     */
    protected $instances = [];

    /**
     * The registered custom instance creators.
     *
     * @var array
     */
    protected $customCreators = [];

    /**
     * Create a new manager instance.
     *
     * @param  \Illuminate\Contracts\Foundation\Application  $app
     * @return void
     */
    public function __construct($app)
    {
        $this->app = $app;
    }

    /**
     * Get the default instance name.
     *
     * @return string
     */
    abstract public function getDefaultInstance();

    /**
     * Set the default instance name.
     *
     * @param  string  $name
     * @return void
     */
    abstract public function setDefaultInstance($name);

    /**
     * Get the instance specific configuration.
     *
     * @param  string  $name
     * @return array
     */
    abstract public function getInstanceConfig($name);

    /**
     * Get an instance instance by name.
     *
     * @param  string|null  $name
     * @return mixed
     */
    public function instance($name = null)
    {
        $name = $name ?: $this->getDefaultInstance();

        return $this->instances[$name] = $this->get($name);
    }

    /**
     * Attempt to get an instance from the local cache.
     *
     * @param  string  $name
     * @return mixed
     */
    protected function get($name)
    {
        return $this->instances[$name] ?? $this->resolve($name);
    }

    /**
     * Resolve the given instance.
     *
     * @param  string  $name
     * @return mixed
     *
     * @throws \InvalidArgumentException
     */
    protected function resolve($name)
    {
        $config = $this->getInstanceConfig($name);

        if (is_null($config)) {
            throw new InvalidArgumentException("Instance [{$name}] is not defined.");
        }

        if (! array_key_exists('driver', $config)) {
            throw new RuntimeException("Instance [{$name}] does not specify a driver.");
        }

        if (isset($this->customCreators[$config['driver']])) {
            return $this->callCustomCreator($config);
        } else {
            $driverMethod = 'create'.ucfirst($config['driver']).'Driver';

            if (method_exists($this, $driverMethod)) {
                return $this->{$driverMethod}($config);
            } else {
                throw new InvalidArgumentException("Instance driver [{$config['driver']}] is not supported.");
            }
        }
    }

    /**
     * Call a custom instance creator.
     *
     * @param  array  $config
     * @return mixed
     */
    protected function callCustomCreator(array $config)
    {
        return $this->customCreators[$config['driver']]($this->app, $config);
    }

    /**
     * Unset the given instances.
     *
     * @param  array|string|null  $name
     * @return $this
     */
    public function forgetInstance($name = null)
    {
        $name ??= $this->getDefaultInstance();

        foreach ((array) $name as $instanceName) {
            if (isset($this->instances[$instanceName])) {
                unset($this->instances[$instanceName]);
            }
        }

        return $this;
    }

    /**
     * Disconnect the given instance and remove from local cache.
     *
     * @param  string|null  $name
     * @return void
     */
    public function purge($name = null)
    {
        $name ??= $this->getDefaultInstance();

        unset($this->instances[$name]);
    }

    /**
     * Register a custom instance creator Closure.
     *
     * @param  string  $name
     * @param  \Closure  $callback
     * @return $this
     */
    public function extend($name, Closure $callback)
    {
        $this->customCreators[$name] = $callback->bindTo($this, $this);

        return $this;
    }

    /**
     * Dynamically call the default instance.
     *
     * @param  string  $method
     * @param  array  $parameters
     * @return mixed
     */
    public function __call($method, $parameters)
    {
        return $this->instance()->$method(...$parameters);
    }
}