source/php/Event.php
public function saveTags()
    {
        if (empty($this->tags)) {
            $terms = wp_get_post_terms($this->ID, 'event_tags', array('fields' => 'all'));
            if (!empty($terms)) {
                foreach ($terms as $term) {
                    wp_remove_object_terms($this->ID, $term->term_id, 'event_tags');
                }
                delete_post_meta($this->ID, 'tags');
            }
        } else {
            wp_set_object_terms($this->ID, $this->tags, 'event_tags', false);
        }
    }
public function saveTags()
    {
        if (empty($this->tags)) {
            $terms = wp_get_post_terms($this->ID, 'event_tags', array('fields' => 'all'));
            if (!empty($terms)) {
                foreach ($terms as $term) {
                    wp_remove_object_terms($this->ID, $term->term_id, 'event_tags');
                }
                delete_post_meta($this->ID, 'tags');
            }
        } else {
            wp_set_object_terms($this->ID, $this->tags, 'event_tags', false);
        }
    }
Saves tags as taxonomy terms
@return void