hs_book.module

<?php

/**
 * @file
 * Implementation of the Hierarchical Select API for the Book module.
 */


//----------------------------------------------------------------------------
// Drupal core hooks.

/**
 * Implementation of hook_menu().
 */
function hs_book_menu($may_cache) {
  $items = array();

  if ($may_cache) {
    $items[] = array(
      'path'               => 'admin/settings/hierarchical_select/book',
      'title'              => t('Book'),
      'description'        => t('Hierarchical Select configuration for Book'),
      'callback'           => 'drupal_get_form',
      'callback arguments' => array('hs_book_admin_settings'),
      'type'               => MENU_LOCAL_TASK,
    );
  }
  return $items;
}

/**
 * Implementation of hook_form_alter().
 */
function hs_book_form_alter($form_id, &$form) {
  if ($form_id == 'book_node_form' && isset($form['parent'])) {
    unset($form['parent']['#options']);
    $form['parent']['#type'] = 'hierarchical_select';
    $form['parent']['#config'] = array(
      'module' => 'hs_book',
      'params' => array(
        'nid' => (isset($form['nid'])) ? $form['nid']['#value'] : NULL,
      ),
      'save_lineage'    => 0,
      'enforce_deepest' => 0,
      'resizable'       => variable_get('hs_book_resizable', 1),
    );
    $form['parent']['#default_value'] = (!is_numeric($form['parent']['#default_value'])) ? 0 : $form['parent']['#default_value'];
  }
}


//----------------------------------------------------------------------------
// Menu callbacks.

/**
 * Form definition; admin settings.
 */
function hs_book_admin_settings() {
  $form['hs_book_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' => variable_get('hs_book_resizable', 1),
  );

  return system_settings_form($form);
}


//----------------------------------------------------------------------------
// Hierarchical Select hooks.

/**
 * Implementation of hook_hierarchical_select_params().
 */
function hs_book_hierarchical_select_params() {
  $params = array(
    'nid', // The nid of the given book page.item. This book page and its children will be excluded from the hierarchy.
  );
  return $params;
}

/**
 * Implementation of hook_hierarchical_select_root_level().
 */
function hs_book_hierarchical_select_root_level($params) {
  $root_level = array();

  // If the user has permission to create new books, add the top-level book page to the menu;
  if (user_access('create new books')) {
    $root_level[0] = '<'. t('top-level') .'>';
  }
  $root_level += hs_book_hierarchical_select_children(-1, $params);

  return $root_level;
}

/**
 * Implementation of hook_hierarchical_select_children().
 */
function hs_book_hierarchical_select_children($parent, $params) {
  // TRICKY: because the book form assumes that the value "0" corresponds to
  // the <top-level page> option (for creating a new menu item at the root
  // level) *AND* 0 is also a pseudo-value in the actual hierarchy (it
  // represents the root), we have to pretend in the code that -1 is the root
  // in the hierarchy instead of 0.
  if ($parent == 0) {
    return array();
  }
  if ($parent == -1) {
    $parent = 0;
  }

  $result = db_query(db_rewrite_sql('SELECT n.nid, n.title FROM {node} n INNER JOIN {book} b ON n.vid = b.vid WHERE n.status = 1 AND b.parent = %d ORDER BY b.weight, n.title'), $parent);

  $children = array();
  while ($node = db_fetch_object($result)) {
    // Don't include the given book page in the hierarchy!
    if (isset($params['nid']) && $params['nid'] == $node->nid) {
      continue;
    }

    $children[$node->nid] = $node->title;
  }

  return $children;
}

/**
 * Implementation of hook_hierarchical_select_lineage().
 */
function hs_book_hierarchical_select_lineage($item, $params) {
  $lineage = array($item);

  while (TRUE) {
    $parent = db_result(db_query("SELECT parent FROM {book} WHERE nid = %d", $item));

    // 0 is the root menu item, so if $parent == 0, the lineage is complete!
    if ($parent == 0)
      break;

    array_unshift($lineage, $parent);
    $item = $parent;
  }

  return $lineage;
}

/**
 * Implementation of hook_hierarchical_select_valid_item().
 */
function hs_book_hierarchical_select_valid_item($item, $params) {
  if (!is_numeric($item) || $item < 0) {
    return FALSE;
  }

  // Item 0 corresponds to the special <top-level page> option.
  if ($item == 0) {
    return TRUE;
  }

  $count = db_result(db_query(db_rewrite_sql("SELECT COUNT(n.nid) FROM {book} n WHERE n.nid = %d"), $item));
  return ($count == 1);
}

/**
 * Implementation of hook_hierarchical_select_item_get_label().
 */
function hs_book_hierarchical_select_item_get_label($item, $params) {
  static $labels = array();

  if (!isset($labels[$item])) {
    $labels[$item] = t(db_result(db_query("SELECT n.title FROM {book} b INNER JOIN {node} n ON b.vid = n.vid WHERE b.nid = %d", $item)));
  }

  return $labels[$item];
}

/**
 * Implementation of hook_hierarchical_select_implementation_info().
 */
function hs_book_hierarchical_select_implementation_info() {
  $info = node_get_types('type', 'book');
  return array(
    'hierarchy type' => t('Book'),
    'entity type'    => t('Node (!book_page)', array('!book_page' => $info->name)),
  );
}