Random Quote Widget

if ( ! class_exists( 'WPIDE_Random_Quote_Widget' ) ) {
    class WPIDE_Random_Quote_Widget extends WP_Widget {
        public function __construct() {
            parent::__construct( 'wpide_random_quote', 'Random Quote', array(
                'description'                 => 'Shows one quote picked at random from your list on each page view.',
                'customize_selective_refresh' => true,
            ) );
        }

        public function widget( $args, $instance ) {
            $lines = isset( $instance['quotes'] ) ? array_values( array_filter( array_map( 'trim', explode( "\n", $instance['quotes'] ) ) ) ) : array();

            if ( ! $lines ) {
                return;
            }

            // "Quote text — Who said it": the part after the last " — " or " - " is the source.
            $parts  = preg_split( '/\s+[—–-]\s+(?=[^—–-]*$)/u', $lines[ array_rand( $lines ) ], 2 );
            $quote  = $parts[0];
            $source = isset( $parts[1] ) ? $parts[1] : '';
            $title  = isset( $instance['title'] ) ? $instance['title'] : '';
            $title  = apply_filters( 'widget_title', $title, $instance, $this->id_base );

            echo $args['before_widget']; // phpcs:ignore WordPress.Security.EscapeOutput -- theme markup.

            if ( '' !== (string) $title ) {
                echo $args['before_title'] . esc_html( $title ) . $args['after_title']; // phpcs:ignore WordPress.Security.EscapeOutput
            }

            echo '<figure class="wpide-random-quote" style="margin:0;"><blockquote style="margin:0;"><p>' . esc_html( $quote ) . '</p></blockquote>';

            if ( '' !== $source ) {
                echo '<figcaption>— ' . esc_html( $source ) . '</figcaption>';
            }

            echo '</figure>';
            echo $args['after_widget']; // phpcs:ignore WordPress.Security.EscapeOutput
        }

        public function form( $instance ) {
            $title  = isset( $instance['title'] ) ? $instance['title'] : '';
            $quotes = isset( $instance['quotes'] ) ? $instance['quotes'] : '';

            echo '<p><label for="' . esc_attr( $this->get_field_id( 'title' ) ) . '">Title:</label><input class="widefat" type="text" id="' . esc_attr( $this->get_field_id( 'title' ) ) . '" name="' . esc_attr( $this->get_field_name( 'title' ) ) . '" value="' . esc_attr( $title ) . '" /></p>';
            echo '<p><label for="' . esc_attr( $this->get_field_id( 'quotes' ) ) . '">Quotes, one per line ("Quote — Source"):</label><textarea class="widefat" rows="8" id="' . esc_attr( $this->get_field_id( 'quotes' ) ) . '" name="' . esc_attr( $this->get_field_name( 'quotes' ) ) . '">' . esc_textarea( $quotes ) . '</textarea></p>';

            return '';
        }

        public function update( $new_instance, $old_instance ) {
            return array(
                'title'  => isset( $new_instance['title'] ) ? sanitize_text_field( $new_instance['title'] ) : '',
                'quotes' => isset( $new_instance['quotes'] ) ? sanitize_textarea_field( $new_instance['quotes'] ) : '',
            );
        }
    }
}

add_action( 'widgets_init', function () {
    register_widget( 'WPIDE_Random_Quote_Widget' );
} );