dkan_featured_topics.module

<?php
/**
 * @file
 * Code for the DKAN Featured Topics feature.
 */

include_once 'dkan_featured_topics.features.inc';

/**
 * Implements hook_page_alter().
 */
function dkan_featured_topics_page_alter(&$page) {
  drupal_add_css(drupal_get_path('module', 'dkan_featured_topics') . '/dkan_featured_topics.css');
}

/**
 * Implements hook_theme_registry_alter().
 */
function dkan_featured_topics_theme_registry_alter(&$theme_registry) {
  $theme_registry['menu_link__main_menu']['function'] = 'dkan_featured_topics_main_menu';
  $theme_registry['menu_link__main_menu']['render element'] = 'element';
  $theme_registry['menu_link__main_menu']['theme path'] = drupal_get_path('module', 'dkan_featured_topics');
}

/**
 * Overrides theme_main_menu() to add topics dropdown.
 */
function dkan_featured_topics_main_menu($variables) {
  $output = "<li class='leaf menu-link-topics featured-topics-menu'>";
  if ($variables['element']['#title'] == t('Topics')) {
    $link = ($variables['element']['#href'] == '<front>') ? '/' : $variables['element']['#href'];
    $output .= '<a href="' . $link . '" class="dropdown-toggle" data-toggle="dropdown" data-target="#"> ' . $variables['element']["#title"] . '<b class="caret"></b></a>';
    $output .= views_embed_view('dkan_topics_featured', 'block_1');
  }
  else {
    return theme('menu_link', $variables);
  }
  $output .= '</li>';
  return $output;
}

/**
 * Adds "Topics" to main menu.
 */
function dkan_featured_topics_add_menu() {
  $main_menu = menu_load_links('main-menu');
  $topics_enabled = variable_get('dkan_featured_topics_menu_item_enabled', TRUE);
  foreach ($main_menu as $link) {
    if ($link['link_title'] == t('Topics')) {
      $topics_enabled = TRUE;
      break;
    }
  }
  if (!$topics_enabled) {
    $item = array(
      'link_path' => '<front>',
      'link_title' => t('Topics'),
      'menu_name' => 'main-menu',
      'weight' => 0,
      'plid' => 0,
      'module' => 'menu',
    );
    menu_link_save($item);
  }
}