Sample Code for Container Resolver

SampleContainerResolverCode.php

<?php
namespace Kanian\ContainerX;

use Kanian\ContainerX\Exceptions\DependencyHasNoDefaultValueException;
use Kanian\ContainerX\Exceptions\DependencyIsNotInstantiableException;
use Psr\Container\ContainerInterface;
use ReflectionClass;
use ReflectionException;
use ReflectionParameter;

/**
 * A psr-11 compliant container
 */
class Container implements ContainerInterface
{
    //...
    public function concretize(string $entry)
    {
        $resolved = [];
        $reflector = $this->getReflector($entry);
        $constructor = null;
        $parameters = [];
        if ($reflector->isInstantiable()) {
            $constructor = $reflector->getConstructor();
            if (!is_null($constructor)) {
                $parameters = $constructor->getParameters();
            }
        } else {
            throw new DependencyIsNotInstantiableException($className);
        }
        if (is_null($constructor) || empty($parameters)) {

            return $reflector->newInstance(); // return new instance from class
        }

        foreach ($parameters as $parameter) {
            $resolved[] = $this->resolveParameter($parameter);
        }

        return $reflector->newInstanceArgs($resolved); // return new instance with dependencies resolved
    }
    
    public function resolveParameter(ReflectionParameter $parameter)
    {
        if ($parameter->getClass() !== null) { // The parameter is a class
            $typeName = $parameter->getType()->__toString();
            if (!$this->isUserDefined($parameter)) { // The parameter is not user defined

                $this->set($typeName); // Register it
            }
            return $this->get($typeName); // Instantiate it
        } else { // The parameter is a built-in primitive type

            if ($parameter->isDefaultValueAvailable()) { // Check if default value for a parameter is available

                return $parameter->getDefaultValue(); // Get default value of parameter
            } else {
                throw new DependencyHasNoDefaultValueException($parameter->name);
            }
        }
    }
    //...
}