<?php

/**
 * @file
 * Nodeorder install file.
 */

/**
 * Implements hook_install().
 *
 * Adds field 'weight' to core table 'taxonomy_index'.
 * @todo: Handle exceptions that could be thrown by DatabaseSchema::addField.
 */
function nodeorder_install() {
  // Define field properties.
  $schema = drupal_get_schema('taxonomy_index');
  $spec = $schema['fields']['weight'];

  // Create an index for 'weight'
  $keys['indexes'] = array('weight' => array('weight'));

  // Add the column to the table.
  db_add_field('taxonomy_index', 'weight', $spec, $keys);

  // Set the weight of the nodeorder module in the system table to ensure that
  // nodeorder can alter forms after the taxonomy module.
  db_update('system')
    ->fields(array('weight' => 5))
    ->condition('name', 'nodeorder')
    ->condition('type', 'module')
    ->execute();
}

/**
 * Implements hook_uninstall().
 *
 * Drops field 'weight' from core table 'taxonomy_index'.
 */
function nodeorder_uninstall() {
  db_drop_index('taxonomy_index', 'weight');
  db_drop_field('taxonomy_index', 'weight');
  // Remove variables.
  variable_del('nodeorder_show_links_on_node');
  variable_del('nodeorder_link_to_ordering_page');
  variable_del('nodeorder_link_to_ordering_page_taxonomy_admin');
  variable_del('nodeorder_override_taxonomy_page');
}

/**
 * Implements hook_schema_alter().
 *
 * Informs drupal_get_schema() of the field addition to 'taxonomy_index'.
 */
function nodeorder_schema_alter(&$schema) {
  $schema['taxonomy_index']['fields']['weight'] = array(
    'type' => 'int',
    'signed' => TRUE,
    'not null' => TRUE,
    'default' => 0,
    'initial' => 0,
    'description' => t('A user-defined weight for each node in its respective category.'),
  );
}

/**
 * Remove an obsolete variable.
 */
function nodeorder_update_7100() {
  variable_del('nodeorder_replace_taxonomy_link');
}