Enhanced WooCommerce: Show upsells based on product attributes

Question

I found this great solution to show related products based on product attributes, but additionally we want to do the same for upsells.

What I've tried so far doesn't work as I believe we have to add some additional information as the related_products function is not the same as upsell.

add_filter( 'woocommerce_upsell_products', 'upsell_products_by_attribute', 10, 3 );
function upsell_products_by_attribute( $upsells, $product_id, $args ) {
    $taxonomy   = 'pa_attribute';

    $term_slugs = wp_get_post_terms( $product_id, $taxonomy, ['fields' => 'slugs'] );

    if ( empty($term_slugs) )
        return $upsells;

    $posts_ids = get_posts( array(
        'post_type'            => 'product',
        'ignore_sticky_posts'  => 1,
        'posts_per_page'       => 6,
        'post__not_in'         => array( $product_id ),
        'tax_query'            => array( array(
            'taxonomy' => $taxonomy,
            'field'    => 'slug',
            'terms'    => $term_slugs,
        ) ),
        'fields'  => 'ids',
        'orderby' => 'rand',
    ) );

    return count($posts_ids) > 0 ? $posts_ids : $upsells;
}

So I'm wondering if it's possible to do the same thing with the upsell part.

Answer 1

You can remove the default action hook woocommerce_after_single_product_summary and re-add it and you can customize the upsells products. Check the code below. The code will go into your active theme's functions.php file.

Change $taxonomy = 'pa_color'; to your custom taxonomy.

function modify_woocommerce_upsell_display_based_on_attribute( $limit = '-1', $columns = 4, $orderby = 'rand', $order = 'desc' ){
    
    remove_action( 'woocommerce_after_single_product_summary', 'woocommerce_upsell_display', 15 );

    global $product;

    if ( ! $product ) {
        return;
    }

    // Handle the legacy filter which controlled posts per page etc.
    $args = apply_filters(
        'woocommerce_upsell_display_args',
        array(
            'posts_per_page' => $limit,
            'orderby'        => $orderby,
            'order'          => $order,
            'columns'        => $columns,
        )
    );

    wc_set_loop_prop( 'name', 'up-sells' );
    wc_set_loop_prop( 'columns', apply_filters( 'woocommerce_upsells_columns', isset( $args['columns'] ) ? $args['columns'] : $columns ) );

    $orderby = apply_filters( 'woocommerce_upsells_orderby', isset( $args['orderby'] ) ? $args['orderby'] : $orderby );
    $order   = apply_filters( 'woocommerce_upsells_order', isset( $args['order'] ) ? $args['order'] : $order );
    $limit   = apply_filters( 'woocommerce_upsells_total', isset( $args['posts_per_page'] ) ? $args['posts_per_page'] : $limit );

    // set your custom taxonomy here.
    $taxonomy   = 'pa_color';

    $term_slugs = wp_get_post_terms( $product->get_id(), $taxonomy, ['fields' => 'slugs'] );

    $posts_ids = get_posts( array(
        'post_type'            => 'product',
        'ignore_sticky_posts'  => 1,
        'posts_per_page'       => 6,
        'post__not_in'         => array( $product->get_id() ),
        'tax_query'            => array( array(
            'taxonomy' => $taxonomy,
            'field'    => 'slug',
            'terms'    => $term_slugs,
        ) ),
        'fields'  => 'ids',
        'orderby' => 'rand',
    ) );

    if( !empty( $posts_ids ) ){

        // Get visible upsells then sort them at random, then limit result set.
        $upsells = wc_products_array_orderby( array_filter( array_map( 'wc_get_product', $posts_ids ), 'wc_products_array_filter_visible' ), $orderby, $order );
        $upsells = $limit > 0 ? array_slice( $upsells, 0, $limit ) : $upsells;

        wc_get_template(
            'single-product/up-sells.php',
            array(
                'upsells'        => $upsells,

                // Not used now, but used in the previous version of up-sells.php.
                'posts_per_page' => $limit,
                'orderby'        => $orderby,
                'columns'        => $columns,
            )
        );
    }

}

add_action( 'woocommerce_after_single_product_summary', 'modify_woocommerce_upsell_display_based_on_attribute', 15 );