Fix ACF menu location rules to work on all Polylang locales

fix-acf-menu-fields-to-polylang.php

<?php
/**
 * Fix ACF menu location rules to work on all Polylang locales
 *
 * Polylang registers localized variations to menu locations and by default
 * ACF cannot hook to all of them unless they are manually all picked.
 * Polylang separates location with three undescores (eaxmple: primary___en).
 *
 * This hook automatically applies all menu location rules to all languages.
 * Works for both nav_menu and nav_menu_item related fields.
 *
 * @param bool  $match        weather this view is match for this field group
 * @param array $rule         matching ruleset
 * @param array $options      info on current view
 * @param array $field_group  registered fields
 *
 * @return bool $match
 */
add_filter('acf/location/rule_match', function ($match, $rule, $options, $field_group) {

  if (is_array($rule) && in_array($rule['param'], ['nav_menu', 'nav_menu_item']) && strstr($rule['value'], 'location/')) {

    $match_menu_position = str_replace('location/', '', $rule['value']);
    $current_menu_id = 0;

    if ($rule['param'] == 'nav_menu_item' && isset($options['nav_menu_item_id']) && !empty($options['nav_menu_item_id'])) {
      $nav_menus = wp_get_post_terms($options['nav_menu_item_id'], 'nav_menu', ['fields' => 'ids']);
      if (is_array($nav_menus) && isset($nav_menus[0])) {
        $current_menu_id = (int) $nav_menus[0];
      }
    } elseif ($rule['param'] == 'nav_menu' && isset($options['nav_menu']) && !empty($options['nav_menu'])) {
      $current_menu_id = (int) $options['nav_menu'];
    }

    if (is_array($options) && !empty($current_menu_id)) {
      $menus = (array) get_nav_menu_locations();
      foreach ($menus as $menu_position => $menu_id) {
        $menu_position_parts = explode('___', $menu_position);
        if ($menu_id == $current_menu_id && $menu_position_parts[0] == $match_menu_position) {
          return true;
        }
      }
    }

  }

  return $match;

}, 10, 4);