Get and display related products in WooCommerce

Question

I have included WooCommerce related products in a theme with the following:

<?php wc_get_template( 'single-product/related.php' ); ?>

This has been copied into my template and is executing.

However, even though I have added various upsells with this product the $related_products variable (used in the loop) is NULL. Is there any other variables at play in order to start showing these related products?

Answer 1

You need much more than that (and the post_id need to be a product) :

global $product; // If not set…

if( ! is_a( $product, 'WC_Product' ) ){
    $product = wc_get_product(get_the_id());
}

$args = array(
    'posts_per_page' => 4,
    'columns'        => 4,
    'orderby'        => 'rand',
    'order'          => 'desc',
);

$args['related_products'] = array_filter( array_map( 'wc_get_product', wc_get_related_products( $product->get_id(), $args['posts_per_page'], $product->get_upsell_ids() ) ), 'wc_products_array_filter_visible' );
$args['related_products'] = wc_products_array_orderby( $args['related_products'], $args['orderby'], $args['order'] );

// Set global loop values.
wc_set_loop_prop( 'name', 'related' );
wc_set_loop_prop( 'columns', $args['columns'] );

wc_get_template( 'single-product/related.php', $args );

Or in a shorter way (which will give you the same) :

global $product;

if( ! is_a( $product, 'WC_Product' ) ){
    $product = wc_get_product(get_the_id());
}

woocommerce_related_products( array(
    'posts_per_page' => 4,
    'columns'        => 4,
    'orderby'        => 'rand'
) );

Both ways are tested and works…