<?php
/**
 * @file
 * pre-render.inc
 *
 * Contains various implementations for #pre_render callbacks on elements.
 */

/**
 * Pre-render fieldset element.
 */
function _bootstrap_pre_render_fieldset($element) {
  // Fieldsets may be rendered outside of a Form API context.
  if (!isset($element['#parents']) || !isset($element['#groups'])) {
    return $element;
  }
  // Inject group member elements belonging to this group.
  $parents = implode('][', $element['#parents']);
  $children = element_children($element['#groups'][$parents]);
  if (!empty($children)) {
    if (empty($element['#default_tab'])) {
      $children_keys = array_values($children);
      $element['#default_tab'] = $element['#groups'][$parents][array_shift($children_keys)]['#id'];
    }
    foreach ($children as $key) {
      // Break references and indicate that the element should be rendered as
      // group member.
      $child = (array) $element['#groups'][$parents][$key];
      $child['#attributes']['id'] = $child['#id'];
      $child['#group_fieldset'] = TRUE;
      // Inject the element as new child element.
      $element[] = $child;

      $sort = TRUE;
    }
    // Re-sort the element's children if we injected group member elements.
    if (isset($sort)) {
      $element['#sorted'] = FALSE;
    }
  }

  if (isset($element['#group'])) {
    $group = $element['#group'];
    // If this element belongs to a group, but the group-holding element does
    // not exist, we need to render it (at its original location).
    if (!isset($element['#groups'][$group]['#group_exists'])) {
      // Intentionally empty to clarify the flow; we simply return $element.
    }
    // If we injected this element into the group, then we want to render it.
    elseif (!empty($element['#group_fieldset'])) {
      // Intentionally empty to clarify the flow; we simply return $element.
    }
    // Otherwise, this element belongs to a group and the group exists, so we do
    // not render it.
    elseif (element_children($element['#groups'][$group])) {
      $element['#printed'] = TRUE;
    }
  }

  return $element;
}