event tags widget

<?php
    class EventTags extends WP_Widget {

        public function __construct() {

            // Instantiate the parent object

            parent::__construct(
                'event-tags',     // Base ID
                'Event tags',      // Name
                array(
                    'classname'   => 'widget--event tags',
                    'description' => 'Shows event tags'
                ) // Args
            );
        }

        public function widget( $args, $instance ) {

            $term_args = array(
                'taxonomy' => 'event-tags',
                'orderby'  => 'count',
                'order'    => 'DESC',
                'number'   => 10,
            );
            $terms = get_terms( $term_args );

            // Widget output
            extract( $args );
            $etw_widgettitle = apply_filters( 'widget_title', $instance['etw_widgettitle'] );

            echo $before_widget;

            if ( $etw_widgettitle ) {
                echo $before_title . $etw_widgettitle . $after_title;
            }

            if ( $terms ) {

                echo '<ul>';
                foreach( $terms as $term ) {
                    echo '<li><a href="' . get_term_link( $term->term_taxonomy_id ) . '">' . $term->name . '</a></li>';
                }
                echo '</ul>';
            }

            echo $after_widget;
        }

        public function update( $new_instance, $old_instance ) {
            // Save widget options
            $instance = $old_instance;
            $instance['etw_widgettitle'] = strip_tags($new_instance['etw_widgettitle']);
            return $instance;
        }

        public function form( $instance ) {
            // Output admin widget options form
            $etw_widgettitle = ! empty( $instance['etw_widgettitle'] ) ? $instance['etw_widgettitle'] : esc_html__( 'Event tags', 'text_domain' );
            ?>
            <p>
                <label for="<?php echo $this->get_field_id('etw_widgettitle'); ?>">Widget title:</label>
                <input class="widefat" id="<?php echo $this->get_field_id('etw_widgettitle'); ?>" name="<?php echo $this->get_field_name('etw_widgettitle'); ?>" type="text" value="<?php if ( $etw_widgettitle ) { echo $etw_widgettitle; } ?>" />
            </p>
        <?php }
    }

    function register_my_widgets() {
        if ( function_exists( 'em_content' ) ) {
            register_widget( 'EventTags' );
        }
    }
    add_action( 'widgets_init', 'register_my_widgets' );