Chapter 09 DependencyResolver.php

DependencyResolver.php

<?php
namespace SimpleMVC\core;

class DependencyResolver {
    private static $map = [];

    public static function set($key, $value) {
        if (!array_key_exists($key, self::$map)) {
            self::$map[$key] = $value;
        }
    }

    public static function resolveDependencies($class) {
        $reflector = new \ReflectionClass($class);
        $method = $reflector->getConstructor();
        $parameters = $method->getParameters();
        $dependencies = [];     

        foreach ($parameters as $parameter) {            
            $parameterType = $parameter->getType();                    

            if ($parameterType === null || $parameterType->isBuiltin()) {                
                $parameterName = $parameter->getName();                
                // Handling non classes parameters
                if (array_key_exists($parameterName, self::$map)) {                    
                    $dependencies[] = self::$map[$parameterName];
                }                
            } else {
                $dependencyClassName = $parameterType->getName();                
                $dependencies[] = self::resolveDependencies($dependencyClassName);
            }            
        }        
        
        return $reflector->newInstanceArgs($dependencies);
    }
}