GetForm

Manager.php

<?php
/**
  * Passthrough from Drupal form to the correct condition for building the preview form
  *
  * @param $form
  *   The form array used in hook_form
  * @param $form_state
  *   The form_state array as used in hook_form
  *
  * @return
  *   A drupal form array created by the root condition
  */
  public function getPreviewForm($form, &$form_state) {
    $root_condition = $this->getRootCondition();
    return drupal_get_form('sps_condition_preview_form', array($root_condition, 'getElement'));
  }