Hi everyone,

I am using version 0.9.9.9 at this moment and the above notice came up in the log files.

I figured it out, is was another query_var that was causing this.

I also use WooCommerce, and their plugin using also the query_vars, but without setting query_vars[‘order’]

So I changed the pre_get_posts(&$query) function in class-piklist-wordpress.php, and it solved my problem.

Just added the && isset($query->query_vars[‘order’]) to the statement

it’s about the lines 178 to 202

function now looks like:

  /**
   * pre_get_posts
   * Get the order parameter if it has to do with meta
   *
   * @param object $query The current query object.
   *
   * @access public
   * @static
   * @since 1.0
   */
  public static function pre_get_posts(&$query)
  {
    if (isset($query->query_vars['orderby']))
    {
      if (in_array($query->query_vars['orderby'], array('meta_value', 'meta_value_num')) && isset($query->query_vars['order']) && !is_null($query->query_vars['order']))
      {
        self::$meta_order = $query->query_vars['order'];        
      }

      if ( isset($query->query_vars['meta_key']) && !is_null($query->query_vars['meta_key']))
      {              
        self::$meta_key = $query->query_vars['meta_key'];
      }
    }
  }

Hope it helps

Tonny