<?php
/**
 * @file
 * The Term Disable Node Listings module allows a user to selectively
 * disable the node listing on taxonomy term pages on a vocabulary basis
 * on the edit vocabulary page.
 */

/**
 * Implements hook_menu_alter().
 */
function disable_term_node_listings_menu_alter(&$items) {
  // Take over from the taxonomy module.
  $items['taxonomy/term/%taxonomy_term'] = array(
    'page callback' => 'disable_term_node_listings_term_page',
    'page arguments' => array(2),
    'access arguments' => array('access content'),
  );
}

/**
 * Menu callback; displays all nodes associated with a term.
 *
 * @param object $term
 *   The taxonomy term.
 *
 * @return string
 *   The page content.
 */
function disable_term_node_listings_term_page($term) {
  // Check if the term that this vocabulary belongs to has listings disabled.
  $disable_status = variable_get('disable_term_node_listings_' . $term->vocabulary_machine_name, 'default');

  switch ($disable_status) {
    case 'hide_listing':
      // Set the title and return all the field data.
      drupal_set_title($term->name);
      return taxonomy_term_view($term, 'full');

    break;

    case '404':
      return MENU_NOT_FOUND;

    break;

    case '403':
      return MENU_ACCESS_DENIED;

    break;

    default:
      // We have to pull in taxonomy's pages include to call its function.
      module_load_include('inc', 'taxonomy', 'taxonomy.pages');
      return taxonomy_term_page($term);

    break;
  }
}

/**
 * Implements hook_form_alter().
 *
 * Used to add toggle checkbox to the vocabulary edit pages.
 */
function disable_term_node_listings_form_alter(&$form, $form_state, $form_id) {
  if ($form_id == 'taxonomy_form_vocabulary' && !isset($form_state['confirm_delete'])) {
    $vocab_machine_name = $form['#vocabulary']->machine_name;
    $disable_status = variable_get('disable_term_node_listings_' . $vocab_machine_name, 'default');

    // Status toggle switch.
    $form['disable_term_node_listings_status'] = array(
      '#type' => 'radios',
      '#weight' => 3,
      '#title' => t('Node listings'),
      '#description' => t('This field controls the display of all terms in this vocabulary.'),
      '#default_value' => $disable_status,
      '#options' => array(
        'default' => t('Use default node listings'),
        'hide_listing' => t('Disable node listing for all terms'),
        '404' => t('Display 404 page'),
        '403' => t('Display 403 page'),
      ),
    );

    $form['#submit'][] = '_disable_term_node_listings_submit_handler';
  }
}

/**
 * Save the status of the taxonomy term to the database.
 */
function _disable_term_node_listings_submit_handler($form, &$form_state) {
  // Machine name is not available when we are deleting a term
  // so don't try to save the variable.
  if (isset($form_state['values']['machine_name'])) {
    $vocab_machine_name = $form_state['values']['machine_name'];

    // Store the status of this vocabulary based on user input.
    $disable_status = $form_state['values']['disable_term_node_listings_status'];
    variable_set('disable_term_node_listings_' . $vocab_machine_name, $disable_status);
  }
}

/**
 * Implements hook_taxonomy_vocabulary_delete().
 */
function disable_term_node_listings_taxonomy_vocabulary_delete($vocabulary) {
  // If the vocabulary gets deleted, clean up our variable as well.
  variable_del('disable_term_node_listings_' . $vocabulary->machine_name);
}

/**
 * Implements hook_taxonomy_vocabulary_update().
 */
function disable_term_node_listings_taxonomy_vocabulary_update($vocabulary) {
  // If the vocabulary machine name changed
  // delete the variable associated with the old name.
  if ($vocabulary->old_machine_name != $vocabulary->machine_name) {
    variable_del('disable_term_node_listings_' . $vocabulary->old_machine_name);
  }
}