<?php

/**
 * @file
 *  Module to enable placeholder or separator menu items.Placeholder is a menu item which is
 *  actually not a link. Something like this is useful with drop down menus where we want to
 *  have a parent link which is actually not linking to a page but which is just acting as a
 *  parent and grouping some children below it.
 *  A separator menu item is something like "-------" which is also not linking anywhere but
 *  merely a mean to structure menus.
 *
 *  Written by Tamir Al Zoubi and Karim Djelid - Servit Open Source Solutions - www.servit.ch
 */

/**
 *Implementation of hook_menu()
 */
function special_menu_items_menu() {
  $items = array();

  //Add nolink and separator as a dummy pages.
  $noLink    = 'nolink';
  $separator = 'separator';

  $items[$noLink] = array(
    'page callback'    => 'special_menu_items_dummy',
    'access callback'  => TRUE,
    'type'             => MENU_CALLBACK,
  );

  $items[$separator] = array(
    'page callback'    => 'special_menu_items_dummy',
    'access callback'  => TRUE,
    'type'             => MENU_CALLBACK,
  );

  $items['admin/settings/special_menu_items'] = array(
    'title'            => 'Special Menu Items',
    'description'      => 'Configure Special Menu Items.',
    'page callback'    => 'drupal_get_form',
    'page arguments'   => array('special_menu_items_admin_settings_form'),
    'access arguments' => array('administer site configuration'),
    'type'             => MENU_NORMAL_ITEM,
  );

  return $items;
}


/**
 * Page callback
*/
function special_menu_items_dummy() {
  $output = 'This is a dummy page used for placeholder and separator menu items. You should not be able to see this page';
  return t($output);
}

/**
 * Override of theme_menu_item()
 * This function will add a class to separator and nolink <li> tags for easier styling
 * Generate the HTML output for a menu item and submenu.
 *
 * @ingroup themeable
 */
function special_menu_itemsoverwrite_menu_item($link, $has_children, $menu = '', $in_active_trail = FALSE, $extra_class = NULL) {
  $class = ($menu ? 'expanded' : ($has_children ? 'collapsed' : 'leaf'));
  if (!empty($extra_class)) {
    $class .= ' '. $extra_class;
  }
  if ($in_active_trail) {
    $class .= ' active-trail';
  }

  if (strpos($link,'class="nolink"') !== FALSE) {
    $class.=' nolink-li';
  }
  if (strpos($link,'class="separator"') !== FALSE) {
    $class.=' separator-li';
  }

  return '<li class="'. $class .'">'. $link . $menu ."</li>\n";
}

/**
 * Override of theme_menu_item_link()
 * This function will render link if it is "nolink" or "separator". Otherwise it will call originally
 * overwriten menu_item_link function.
 */
function special_menu_itemsoverwrite_menu_item_link($link) {
  global $theme_key;
  
  $theme_overwrite = variable_get('oldtheme_menu_item_link', array());
  
  if (empty($link['localized_options'])) {
    $link['localized_options'] = array();
  }

  if (strpos($link['href'], 'nolink') === 0) {
    // Allow if the menu link is nolink:
    $link['localized_options']['html'] = TRUE;

    //Retrieve tag for nolink menu item
    $tag=variable_get('special_menu_items_nolink_tag','<span>');

    //Set class for nolink
    $css='nolink';

    //Return HTML span instead of a link
    return render_menu_item($tag,$link['title'],$css);
  }
  elseif (strpos($link['href'], 'separator') === 0) {
    // Allow if the menu link is separator
    $link['localized_options']['html'] = TRUE;

    //Retrieve tags and value for separator menu item
    $tag=variable_get('special_menu_items_separator_tag','<span>');
    $value=variable_get('special_menu_items_separator_value','<hr>');

    //Set class for separator
    $css='separator';

    //Return separator menu item
    return render_menu_item($tag,$value,$css);
  }
  elseif (array_key_exists($theme_key, $theme_overwrite) && function_exists($theme_overwrite[$theme_key])) {
    return call_user_func($theme_overwrite[$theme_key], $link);
  }
  else {
    theme_menu_item_link($link);
  }
}

/**
 * Returns menu item rendered.
 */
function render_menu_item($tag,$value,$css=null) {
  $length=strlen($tag);

  //Validate the tags
  if ($tag[0]=='<' && $tag[$length-1]=='>') {
    $closingtag=str_replace('<','</',$tag);
    if($css)
        $tag=str_replace('>',' class="'.$css.'">',$tag);
  }
  else {
    if ($css) {
      $classtag = '<' . $tag . ' class="' . $css . '">';
      $tag = '<' . $tag . '>';
      $closingtag = str_replace('<', '</', $tag);
      $tag = $classtag;
    }
    else {
      $tag = '<' . $tag . '>';
      $closingtag = str_replace('<', '</', $tag);
    }
  }
  return $tag.$value.$closingtag;
}

/**
 * Implementation of hook_theme_registry_alter()
 * We replace theme_menu_item_link with our own function.
 */
function special_menu_items_theme_registry_alter(&$theme_registry) {
  global $theme_key;

  $theme_overwrite = variable_get('oldtheme_menu_item_link', array());
  // Save previous value from registry in case another theme overwrites menu_item_link
  $theme_overwrite[$theme_key] = $theme_registry['menu_item_link']['function'];
  
  //Store the value
  variable_set('oldtheme_menu_item_link', $theme_overwrite);

  // Replace theme_menu_item_link with our special_menu_itemsoverwrite_menu_item_link.
   $theme_registry['menu_item_link']['function'] = 'special_menu_itemsoverwrite_menu_item_link';
   $theme_registry['menu_item_link']['theme paths'] = drupal_get_path('module', 'special_menu_items');;
   $theme_registry['menu_item']['function'] = 'special_menu_itemsoverwrite_menu_item';
}

/**
 * Implementation of hook_form_alter()
 * Description changed, added nolink and separator as path types.
 */
function special_menu_items_form_alter(&$form, $form_state, $form_id) {

  if ($form_id == 'menu_edit_item') {
    $default_value = $form['menu']['link_path']['#default_value'];

    if(preg_match('/^nolink\/[0-9]+$/',$default_value)) {
      $default_value='nolink';
    }
    elseif (preg_match("/^separator\/[0-9]+$/",$default_value)) {
      $default_value='separator';
    }

    $form['menu']['link_path']['#default_value'] = $default_value;
    $form['menu']['link_path']['#description'] =  t('The path this menu item links to. This can be an internal Drupal path such as %add-node or an external URL such as %drupal. Enter %front to link to the front page, enter "nolink" to generate non-linkable item, enter "separator" to generate separator item.', array('%front' => '<front>', '%add-node' => 'node/add', '%drupal' => 'http://drupal.org'));
  }
}

/**
 * Implementation of hook_init().
 */
function special_menu_items_init() {

  //Make breadcrumb of nolink menu item nonlinkable.
  $breadcrumb = drupal_get_breadcrumb();

  foreach ($breadcrumb as $key=>$crumb) {

    if (strlen(strstr($crumb,'nolink'))>0) {
      $crumb=strip_tags($crumb);
      $tag=variable_get('special_menu_items_nolink_tag','<span>');
      $breadcrumb[$key]=render_menu_item($tag,$crumb);
    }
  }
  drupal_set_breadcrumb($breadcrumb);
}

/**
 * Special Menu Items admin settings form.
 *
 * @return
 * The settings form used by Special Menu Items.
 */
function special_menu_items_admin_settings_form() {
  $form['special_menu_items_nolink_tag'] = array(
    '#type' => 'textfield',
    '#title' => t('HTML tag for "nolink"'),
    '#description' => t('By default, Special Menu Items will use a span tag for the nolink menu item. Here you can specify your own tag.'),
    '#default_value' => variable_get('special_menu_items_nolink_tag', '<span>'),

  );

  $form['special_menu_items_separator_tag'] = array(
    '#type' => 'textfield',
    '#title' => t('HTML tag for "separator"'),
    '#description' => t('By default, Special Menu Items will use a span tag for the separator menu item. Here you can specify your own tag.'),
    '#default_value' => variable_get('special_menu_items_separator_tag', '<span>'),

  );

    $form['special_menu_items_separator_value'] = array(
    '#type' => 'textfield',
    '#title' => t('Value to be displayed for the "separator"'),
    '#description' => t('By default, Special Menu Items will use a "&lt;hr&gt;" value for the separator. You can specify your own value for the separator.'),
    '#default_value' => variable_get('special_menu_items_separator_value', '<hr>'),

  );

  return system_settings_form($form);
}

function special_menu_items_footer() {
  if (strpos($_GET['q'],'admin/build/menu-customize') !== FALSE) {
    //do all links in db
    global $db_type;
    if ($db_type == 'pgsql') {
      db_query("UPDATE {menu_links} SET link_path=link_path||'/'||mlid WHERE (link_path='nolink' OR link_path='separator') AND hidden != -1");
    }
    else {
      db_query("UPDATE {menu_links} SET link_path=CONCAT(CONCAT(link_path,'/'),mlid) WHERE (link_path='nolink' OR link_path='separator') AND hidden!=-1");
    }

	  cache_clear_all();
  }
}