Shinoa\DIContainer

<?php
namespace Shinoa\StudentsList;


use Shinoa\StudentsList\Exceptions\DIContainerException;

/**
 * Use DIContainer to define factories and get only those data and objects, that you need at the time.
 * @package Shinoa\StudentsList
 */
class DIContainer
{
    /**
     * Contains factories, used to create certain data or object.
     *
     * @var array
     */
    protected $services = array();

    /**
     * Contains created objects, that need not to be recreated
     * @var array
     */
    protected $objects = array();

    /**
     * Memorizes callable factory with given name.
     *
     * @param string $name
     * @param callable $factory
     * @throws DIContainerException
     */
    public function register(string $name, callable $factory)
    {
        if ( !array_key_exists($name, $this->services) ) {
            $this->services[$name] = $factory;
        } else {
            throw new DIContainerException('Service name already occupied');
        }
    }

    /**
     * Returns data by name, if there is a defined factory to produce it.
     *
     * @param string $name
     * @return mixed
     * @throws DIContainerException
     */
    public function get(string $name)
    {
        if ( array_key_exists($name, $this->objects) ) {
            $result = $this->objects[$name];
        } else {
            if (array_key_exists($name, $this->services)) {
                $result = $this->services[$name]($this);
            } else {
                throw new DIContainerException('Trying to call nonexistant service');
            }
        }
        return $result;
    }
}