class ObjectIterator

class ObjectIterator implements \Iterator, \Countable {
    
    /** @var object */
    private $object;
    
    /** @var int */
    private $position = 0;
    
    /** @var array */
    private $data = array();
    
    /** @var bool */
    private $initialized = false;
    
    /**
     * @param object $object
     */
    public function __construct($object) {
        $this->object = $object;
    }
    
    /**
     * {@inheritdoc}
     */
    public function current() {
        $this->initialize();
        return $this->data[$this->position];
    }
    
    /**
     * {@inheritdoc}
     */
    public function next() {
        $this->initialize();
        $this->position++;
    }
    
    /**
     * {@inheritdoc}
     */
    public function key() {
        $this->initialize();
        return $this->position;
    }
    
    /**
     * {@inheritdoc}
     */
    public function valid() {
        $this->initialize();
        return isset($this->data[$this->position]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function rewind() {
        $this->initialize();
        $this->position = 0;
    }
    
    /**
     * {@inheritdoc}
     */
    public function count() {
        $this->initialize();
        return count($this->data);
    }
    
    /**
     * Initializer
     */
    private function initialize() {
        if (!$this->initialized) {
            $this->data = $this->buildDataFromObject($this->object);
            $this->initialized = true;
        }
    }
    
    /**
     * @param object $object
     *
     * @return array
     */
    private function buildDataFromObject($object) {
        $result = array();
        $stack = new \SplStack();
        $stack->push($object);
        while (!$stack->isEmpty()) {
            $current = $stack->pop();
            if (is_object($current)) {
                array_push($result, $current);
            }
            foreach ($this->getDataFromItem($current) as $propertyName => $propertyValue) {
                if (is_object($propertyValue) || is_array($propertyValue)) {
                    $stack->push($propertyValue);
                }
            }
        }
        return $result;
    }
    
    /**
     * @param object|array $item
     *
     * @return array
     */
    private function getDataFromItem($item) {
        if (!is_object($item) && !is_array($item)) {
            return array();
        }
        return is_object($item) ? get_object_vars($item) : $item;
    }

}