Aggiunge shortcode per prodotti in offerta in Woocommerce

sales.php

<?php 

/*
Plugin Name: Woocommerce Sale Products Shortcode
Version: 0.1

* Usage: [sale_products]
* Options & Default
    per_page=12
    columns=4
    orderby=title
    order=asc
*/ 

/**
 * List all products on sale
 *
 * @access public
 * @param array $atts
 * @return string
 */
function woocommerce_sale_products( $atts ){
    global $woocommerce_loop;

    extract( shortcode_atts( array(
        'per_page'      => '12',
        'columns'       => '4',
        'orderby'       => 'title',
        'order'         => 'asc'
        ), $atts ) );

    $args = array(
        'post_type' => 'product',
        'post_status' => 'publish',
        'ignore_sticky_posts'   => 1,
        'orderby' => $orderby,
        'order' => $order,
        'posts_per_page' => $per_page,
        'meta_query' => array(
            array(
                'key' => '_visibility',
                'value' => array('catalog', 'visible'),
                'compare' => 'IN'
            ),
            array(
                'key' => '_sale_price',
                'value' => 0,
                'compare' => '>',
                'type' => 'NUMERIC'
            )
        )
    );

    ob_start();

    $products = new WP_Query( $args );

    $woocommerce_loop['columns'] = $columns;

    if ( $products->have_posts() ) : ?>

        <ul class="products">

            <?php while ( $products->have_posts() ) : $products->the_post(); ?>

                <?php woocommerce_get_template_part( 'content', 'product' ); ?>

            <?php endwhile; // end of the loop. ?>

        </ul>

    <?php endif;

    wp_reset_query();

    return ob_get_clean();
}

add_shortcode('sale_products', 'woocommerce_sale_products');

?>