$strings['item'],
    '!items' => $strings['items'],
    '!entity' => $strings['entity'],
    '!entities' => $strings['entities'],
    '!hierarchy' => $strings['hierarchy'],
    '!hierarchies' => $strings['hierarchies']
  );
  $form = array(
    '#tree' => TRUE,
    '#type' => 'fieldset',
    '#title' => t('Hierarchical Select configuration'),
    '#attributes' => array(
      'class' => array('hierarchical-select-config-form'),
      'id'    => 'hierarchical-select-config-form-' . $config_id,
    ),
    '#attached' => array(
      'css' => array(
        drupal_get_path('module', 'hierarchical_select') . '/includes/common_config_form.css'
      ),
      'js' => array(
        array(
          'type' => 'file',
          'data' => drupal_get_path('module', 'hierarchical_select') . '/includes/common_config_form.js',
        ),
        array(
          'type' => 'setting',
          'data' => array('HierarchicalSelect' => array('configForm' => array($config_id))),
        ),
      ),
    )
  );
  $form['config_id'] = array('#type' => 'value', '#value' => $config_id);
  // TODO: really make this a *live* preview, i.e. refresh the preview on each
  // change in the form. This cannot be done easily in Drupal 5 or 6, so let's
  // do so in Drupal 7. See cfg.livePreview in common_config_form.js.
  $form['live_preview'] = array(
    '#type' => 'fieldset',
    '#title' => t('Preview'),
    '#description' => t('This is what the Hierarchical Select will look like with your current configuration.'),
    '#collapsible' => FALSE,
    '#attributes' => array('class' => array('live-preview')),
  );
  $form['live_preview']['example'] = array(
    '#type' => 'hierarchical_select',
    '#required' => $preview_is_required,
    '#title' => t('Preview'),
    '#description' => t('The description.'),
    // Skip al validation for this form element: the data collected through it
    // is always discarded, it's merely here for illustrative purposes.
    '#validated' => TRUE,
  );
  hierarchical_select_common_config_apply($form['live_preview']['example'], $config_id, array_merge($defaults_override, array('module' => $module, 'params' => $params)));
  $form['save_lineage'] = array(
    '#type' => 'radios',
    '#title' => t('Save lineage'),
    '#options' => array(
      1 => t('Save !item lineage', $args),
      0 => t('Save only the deepest !item', $args),
    ),
    '#default_value' => (isset($config['save_lineage'])) ? $config['save_lineage'] :  NULL,
    '#description' => t(
      'Saving the !item lineage means saving the the !item itself and all
      its ancestors.',
      $args
    ),
  );
  $form['enforce_deepest'] = array(
    '#type' => 'radios',
    '#title' => t('Level choice'),
    '#options' => array(
      1 => t('Force the user to choose a !item from a deepest level', $args),
      0 => t('Allow the user to choose a !item from any level', $args),
    ),
    '#default_value' => (isset($config['enforce_deepest'])) ? $config['enforce_deepest'] : NULL,
    '#description' => t(
      'This setting determines from which level in the !hierarchy tree a
      user can select a !item.',
      $args
    ),
    '#attributes' => array('class' => array('enforce-deepest')),
  );
  $form['resizable'] = array(
    '#type' => 'radios',
    '#title' => t('Resizable'),
    '#description' => t(
      "When enabled, a handle appears below the Hierarchical Select to allow
      the user to dynamically resize it. Double clicking will toggle between
      the smallest and a sane 'big size'."
    ),
    '#options' => array(
      0 => t('Disabled'),
      1 => t('Enabled'),
    ),
    '#default_value' => (isset($config['resizable'])) ? $config['resizable'] : NULL,
    '#attributes' => array('class' => array('resizable')),
  );
  $form['level_labels'] = array(
    '#tree' => TRUE,
    '#type' => 'fieldset',
    '#title' => t('Level labels'),
    '#description' => t(
      'When the user is allowed to choose a !item from any level in the
      Level choice setting, you can enter a label for each
      level.
      However, when the user is only allowed to choose a !item from the
      deepest level, then you can only enter a label for the root
      level.',
      $args
    ),
    '#collapsible' => TRUE,
  );
  $form['level_labels']['status'] = array(
    '#type' => 'checkbox',
    '#title' => t('Enable level labels'),
    '#default_value' => (isset($config['level_labels']['status'])) ? $config['level_labels']['status'] : NULL,
    '#attributes' => array('class' => array('level-labels-status')),
  );
  for ($depth = 0; $depth <= $max_hierarchy_depth; $depth++) {
    $form['level_labels']['labels'][$depth] = array(
      '#type' => 'textfield',
      '#size' => 20,
      '#maxlength' => 255,
      '#default_value' => (isset($config['level_labels']['labels'][$depth])) ? $config['level_labels']['labels'][$depth] : NULL,
      '#attributes' => array('class' => array('level-label')),
    );
  }
  $form['level_labels']['#theme'] = 'hierarchical_select_common_config_form_level_labels';
  $form['level_labels']['#strings'] = $strings;
  $form['dropbox'] = array(
    '#type' => 'fieldset',
    '#title' => t('Dropbox settings'),
    '#description' => t('The dropbox allows the user to make multiple selections.'),
    '#collapsible' => TRUE,
  );
  $form['dropbox']['status'] = array(
    '#type' => 'checkbox',
    '#title' => t('Enable the dropbox'),
    '#default_value' => (isset($config['dropbox']['status'])) ? $config['dropbox']['status'] : NULL,
    '#attributes' => array('class' => array('dropbox-status')),
  );
  $form['dropbox']['title'] = array(
    '#type' => 'textfield',
    '#title' => t('Title'),
    '#description' => t('The title you enter here appears above the dropbox.'),
    '#size' => 20,
    '#maxlength' => 255,
    '#default_value' => (isset($config['dropbox']['title'])) ? $config['dropbox']['title'] : NULL,
    '#attributes' => array('class' => array('dropbox-title')),
  );
  $form['dropbox']['limit'] = array(
    '#type' => 'textfield',
    '#title' => t('Limit the number of selections'),
    '#description' => t(
      'Limits the number of selections that can be added to the dropbox.
      0 means no limit.
      
      Note: the "Save !item lineage" option has no effect on this, even if
      a lineage consists of 3 !items, this will count as only one selection
      in the dropbox.',
      $args
    ),
    '#size' => 5,
    '#maxlength' => 5,
    '#default_value' => (isset($config['dropbox']['limit'])) ? $config['dropbox']['limit'] : NULL,
    '#attributes' => array('class' => array('dropbox-limit')),
  );
  $form['dropbox']['reset_hs'] = array(
    '#type' => 'radios',
    '#title' => t('Reset selection of hierarchical select'),
    '#description' => t(
      'This setting determines what will happen to the hierarchical select
      when the user has added a selection to the dropbox.'
    ),
    '#options' => array(
      0 => t('Disabled'),
      1 => t('Enabled'),
    ),
    '#default_value' => (isset($config['dropbox']['reset_hs'])) ? $config['dropbox']['reset_hs'] : NULL,
    '#attributes' => array('class' => array('dropbox-reset-hs')),
  );
  $form['dropbox']['sort'] = array(
    '#type' => 'checkbox',
    '#title' => t('Sort dropbox items'),
    '#description' => t('Automatically sort items added to the dropbox. If unchecked new items will be added to the end of the dropbox list.'),
    '#default_value' => (isset($config['dropbox']['sort'])) ? $config['dropbox']['sort'] : 1,
    '#attributes' => array('class' => array('dropbox-sort')),
  );
  if (module_hook($module, 'hierarchical_select_create_item')) {
    $form['editability'] = array(
      '#type' => 'fieldset',
      '#title' => t('Editability settings'),
      '#description' => t(
        'You can allow the user to add new !items to this
        !hierarchy through Hierarchical Select.',
        $args
      ),
      '#collapsible' => TRUE,
    );
    $form['editability']['status'] = array(
      '#type' => 'checkbox',
      '#title' => t('Allow creation of new !items', $args),
      '#options' => array(
        0 => t('Disabled'),
        1 => t('Enabled'),
      ),
      '#default_value' => (isset($config['editability']['status'])) ? $config['editability']['status'] : NULL,
      '#attributes' => array('class' => array('editability-status')),
    );
    for ($depth = 0; $depth <= $max_hierarchy_depth; $depth++) {
      $form['editability']['item_types'][$depth] = array(
        '#type' => 'textfield',
        '#size' => 20,
        '#maxlength' => 255,
        '#default_value' => (isset($config['editability']['item_types'][$depth])) ? $config['editability']['item_types'][$depth] : NULL,
        '#attributes' => array('class' => array('editability-item-type')),
      );
    }
    for ($depth = 0; $depth <= $max_hierarchy_depth; $depth++) {
      $form['editability']['allowed_levels'][$depth] = array(
        '#type' => 'checkbox',
        '#default_value' => (isset($config['editability']['allowed_levels'][$depth])) ? $config['editability']['allowed_levels'][$depth] : 1,
      );
    }
    $form['editability']['allow_new_levels'] = array(
      '#type' => 'checkbox',
      '#title' => t('Allow creation of new levels'),
      '#default_value' => $config['editability']['allow_new_levels'],
      '#description' => t(
        'Allow the user to create child !items for !items that do not yet have
        children.',
        $args
      ),
      '#attributes' => array('class' => array('editability-allow-new-levels')),
    );
    $form['editability']['max_levels'] = array(
      '#type' => 'select',
      '#title' => t('Maximum number of levels allowed'),
      '#options' => array(
        0 => t('0 (no limit)'), 1, 2, 3, 4, 5, 6, 7, 8, 9
      ),
      '#default_value' => (isset($config['editability']['max_levels'])) ? $config['editability']['max_levels'] : NULL,
      '#description' => t(
        'When the user is allowed to create new levels, this option prevents
        the user from creating extremely deep !hierarchies.',
        $args
      ),
      '#attributes' => array('class' => array('editability-max-levels')),
    );
    $form['editability']['#theme'] = 'hierarchical_select_common_config_form_editability';
    $form['editability']['#strings'] = $strings;
  }
  if (module_hook($module, 'hierarchical_select_entity_count')) {
    $form['entity_count'] = array(
      '#type' => 'fieldset',
      '#title' => t('Entity Count'),
      '#collapsible' => TRUE,
    );
    $form['entity_count']['enabled'] = array(
      '#type' => 'checkbox',
      '#title' => t('Display number of entities'),
      '#description' => t('Display the number of entities associated with the !item. Do not forget to check which entities should be counted.', $args),
      '#default_value' => isset($config['entity_count']['enabled']) ? $config['entity_count']['enabled'] : FALSE,
      '#weight' => -1,
      '#attributes' => array('class' => array('entity-count-enabled')),
    );
    $form['entity_count']['require_entity'] = array(
      '#type' => 'checkbox',
      '#title' => t('Require associated entity'),
      '#description' => t('If checked only !items that have at least one entity associated with them will be displayed.', $args),
      '#default_value' => (isset($config['entity_count']['require_entity'])) ? $config['entity_count']['require_entity'] : FALSE,
    );
    $form['entity_count']['settings'] = array(
      '#type' => 'fieldset',
      '#title' => t('Entity count settings'),
      '#collapsible' => TRUE,
      '#collapsed' => FALSE,
      '#weight' => -1,
      '#attributes' => array('class' => array('entity-count-settings')),
    );
    $form['entity_count']['settings']['count_children'] = array(
      '#type' => 'checkbox',
      '#title' => t('Also count children of !item.', $args),
      '#description' => t('If checked this will result in a larger number because the children will be counted also.'),
      '#default_value' => isset($config['entity_count']['settings']['count_children']) ? $config['entity_count']['settings']['count_children'] : FALSE,
    );
    $form['entity_count']['settings']['entity_types'] = array(
      '#type' => 'item',
      '#title' => t('Select entities that should be counted.'),
      '#description' => t('Select entity type or one of it\'s bundles that should be counted'),
    );
    $entity_info = entity_get_info();
    foreach ($entity_info as $entity => $entity_info) {
      if (!empty($entity_info['bundles']) && $entity_info['fieldable'] === TRUE) {
        $options = array();
        $default_values = array();
        $form['entity_count']['settings']['entity_types'][$entity] = array(
          '#type' => 'fieldset',
          '#title' => check_plain($entity_info['label']),
          '#collapsible' => TRUE,
          '#collapsed' => TRUE,
        );
        foreach ($entity_info['bundles'] as $bundle => $bundle_info) {
          $options[$bundle] = check_plain($bundle_info['label']);
          $default_values[$entity][$bundle] = isset($config['entity_count']['settings']['entity_types'][$entity]['count_' . $entity][$bundle]) ? $config['entity_count']['settings']['entity_types'][$entity]['count_' . $entity][$bundle] : 0;
        }
        $form['entity_count']['settings']['entity_types'][$entity]['count_' . $entity] = array(
          '#type' => 'checkboxes',
          '#options' => $options,
          '#default_value' => $default_values[$entity],
        );
      }
    }
  }
  return $form;
}
/**
 * Submit callback for the hierarchical_select_common_config_form form.
 */
function hierarchical_select_common_config_form_submit($form, &$form_state) {
  $config = _hierarchical_select_get_form_item_by_parents($form_state['values'], $form['#hs_common_config_form_parents']);
  // Don't include the value of the live preview in the config.
  unset($config['live_preview']);
  hierarchical_select_common_config_set($config['config_id'], $config);
}
/**
 * Get the form element of a form that has a certain lineage of parents.
 *
 * @param $form
 *   A structured array for use in the Forms API.
 * @param $parents
 *   An array of parent form element names.
 * @return
 *  The form element that has the specified lineage of parents.
 */
function _hierarchical_select_get_form_item_by_parents($form, $parents) {
  if (count($parents)) {
    $parent = array_shift($parents);
    return _hierarchical_select_get_form_item_by_parents($form[$parent], $parents);
  }
  else {
    return $form;
  }
}