Promotion Widget

class Promotion_Widget extends WP_Widget {

	public function __construct() {

		parent::__construct(
			'promotion',
			__( 'Promotional Widget', 'kln' ),
			array(
				'description' => __( 'Use this widget to promote an event, store product, etc.', 'kln' ),
				'classname'   => 'feature--promotion',
			)
		);

	}

	public function widget( $args, $instance ) {

	}

	public function form( $instance ) {

		// Set default values
		$instance = wp_parse_args( (array) $instance, array( 
			'promo_title' => '',
			'promo_url' => '',
		) );

		// Retrieve an existing value from the database
		$promo_title = !empty( $instance['promo_title'] ) ? $instance['promo_title'] : '';
		$promo_url = !empty( $instance['promo_url'] ) ? $instance['promo_url'] : '';

		// Form fields
		echo '<p>';
		echo '	<label for="' . $this->get_field_id( 'promo_title' ) . '" class="promo_title_label">' . __( 'Promotion Title', 'kln' ) . '</label>';
		echo '	<input type="text" id="' . $this->get_field_id( 'promo_title' ) . '" name="' . $this->get_field_name( 'promo_title' ) . '" class="widefat" placeholder="' . esc_attr__( 'Product, Event, Etc.', 'kln' ) . '" value="' . esc_attr( $promo_title ) . '">';
		echo '	<span class="description">' . __( 'Title of the promotion', 'kln' ) . '</span>';
		echo '</p>';

		echo '<p>';
		echo '	<label for="' . $this->get_field_id( 'promo_url' ) . '" class="promo_url_label">' . __( 'URL', 'kln' ) . '</label>';
		echo '	<input type="url" id="' . $this->get_field_id( 'promo_url' ) . '" name="' . $this->get_field_name( 'promo_url' ) . '" class="widefat" placeholder="' . esc_attr__( 'https://example.com', 'kln' ) . '" value="' . esc_attr( $promo_url ) . '">';
		echo '</p>';

	}

	public function update( $new_instance, $old_instance ) {

		$instance = $old_instance;

		$instance['promo_title'] = !empty( $new_instance['promo_title'] ) ? strip_tags( $new_instance['promo_title'] ) : '';
		$instance['promo_url'] = !empty( $new_instance['promo_url'] ) ? strip_tags( $new_instance['promo_url'] ) : '';

		return $instance;

	}

}

function register_widgets() {
	register_widget( 'Promotion_Widget' );
}
add_action( 'widgets_init', 'register_widgets' );