<?php

// TODO: not working
class IsisSubfieldIterator implements Iterator
{
  private $position = 0;
  private $class;
  private $field;
  private $subfields;
  private $keys;

  public function __construct($class, $field) {
    $this->class     = $class;
    $this->field     = $field;
    $this->subfields = $class->getSubfields($field);
    $this->keys      = array_values($this->subfields);
    $this->total     = count($this->class->result[$field['name']);
    print_r($field);
  }

  function subfield() {
    return $this->subfields[$this->key()];
  }

  function rewind() {
    $this->position = 0;
  }

  function current() {
    $value = $this->class->getSubfield($this->field, $this->subfield());
    return $this->class->explodeValue($value);
  }

  function key() {
    return $this->keys[$this->position];
  }

  function next() {
    ++$this->position;
  }

  function valid() {
    return isset($this->keys[$this->position]) && ($this->current() != null);
  }
}