Related Products

Hi,

Via woocommerce_related_products hook you can adjust the query to your wishes. The following example shows, for example, how you can display related products based on the same product title.

https://businessbloomer.com/woocommerce-custom-related-products/

/**
 * @snippet       Get Related Products by Same Title @ WooCommerce Single
 * @how-to        Get CustomizeWoo.com FREE
 * @author        Rodolfo Melogli
 * @compatible    WooCommerce 3.8
 * @donate $9     https://businessbloomer.com/bloomer-armada/
 */
 
add_filter( 'woocommerce_related_products', 'bbloomer_related_products_by_same_title', 9999, 3 ); 
 
function bbloomer_related_products_by_same_title( $related_posts, $product_id, $args ) {
   $product = wc_get_product( $product_id );
   $title = $product->get_name();
   $related_posts = get_posts( array(
      'post_type' => 'product',
      'post_status' => 'publish',
      'title' => $title,
      'fields' => 'ids',
      'posts_per_page' => -1,
      'exclude' => array( $product_id ),
   ));
   return $related_posts;
}

You can adjust this to your needs.

This code works for ALL categories that include the product itself

function my_related_products_by_same_categories( $related_posts, $product_id, $args ) {
    // get categories
    $terms = wp_get_post_terms( $product_id, 'product_cat' );

    // set array
    $cats_array = [];
	
    foreach ( $terms as $term ) {
        $cats_array[] = $term->term_id;
    }
	
    $related_posts = get_posts( array(
        'post_type' => 'product',
	'post_status' => 'publish',
	'posts_per_page' => -1,
	'no_found_rows' => 1,
	'post__not_in' => array( $product_id),
	'tax_query' => array( 
	    array(
		'taxonomy' => 'product_cat',
		'field' => 'id',
		'terms' => $cats_array
	    )
	)
    ));
    return $related_posts;
}
add_filter( 'woocommerce_related_products', 'my_related_products_by_same_categories', 9999, 3 );

And this ONLY for the same MAIN category

function my_related_products_by_same_main_category( $related_posts, $product_id, $args ) {
    // get categories
    $terms = wp_get_post_terms( $product_id, 'product_cat' );

    // set array
    $cats_array = [];
	
    foreach ( $terms as $term ) {
	if ($term->parent == 0) { //check for parent terms only
	    $cats_array[] = $term->term_id;
	}
    }
	
    $related_posts = get_posts( array(
        'post_type' => 'product',
	'post_status' => 'publish',
	'posts_per_page' => -1,
	'no_found_rows' => 1,
	'post__not_in' => array( $product_id),
	'tax_query' => array( 
	    array(
		'taxonomy' => 'product_cat',
		'field' => 'id',
		'terms' => $cats_array
	    )
	)
    ));
    return $related_posts;
}
add_filter( 'woocommerce_related_products', 'my_related_products_by_same_main_category', 9999, 3 );

• This reply was modified 6 years, 6 months ago by crslz.

the 2nd example only works for items that contain a main category, the first example will show related products with the same category as the current product (or if the product contains multiple categories, for all those categories).

You can also apply it as follows, but then it will only work for products that contain a main category

function my_related_products_by_same_main_category( $related_posts, $product_id, $args ) {
    // get categories
    $terms = wp_get_post_terms( $product_id, 'product_cat' );

	foreach ($terms as $term) {
		// gets product cat id
		$product_cat_id = $term->term_id;

		// gets an array of all parent category levels
		$product_parent_categories_all_hierachy = get_ancestors( $product_cat_id, 'product_cat' );  

		// This cuts the array and extracts the last set in the array
		$last_parent_cat = array_slice($product_parent_categories_all_hierachy, -1, 1, true);
	}
	
    $related_posts = get_posts( array(
        'post_type' => 'product',
		'post_status' => 'publish',
		'posts_per_page' => -1,
		'no_found_rows' => 1,
		'post__not_in' => array( $product_id),
		'tax_query' => array( 
			array(
				'taxonomy' => 'product_cat',
				'field' => 'id',
				'terms' => $last_parent_cat
			)
		)
    ));
	
    return $related_posts;
}
add_filter( 'woocommerce_related_products', 'my_related_products_by_same_main_category', 9999, 3 );

Maybe you should try changing the priority number?

add_filter( 'woocommerce_related_products', 'my_related_products_by_same_main_category', 9999, 3 );

to

add_filter( 'woocommerce_related_products', 'my_related_products_by_same_main_category', 10, 3 );

You can also always debug by applying print_r or var_dump to the variables, so that you can see which values ​​these contain but on a live website this is indeed not recommended. WP staging is recommended for this.

Then the only way is debugging. Can you execute this code with a product and post the output here? afterwards you can safely remove the code again.

The output can be found just above the related products.

function my_related_products_by_same_categories( $related_posts, $product_id, $args ) {
    // get categories
    $terms = wp_get_post_terms( $product_id, 'product_cat' );

    // set array
    $cats_array = [];
	
    foreach ( $terms as $term ) {
	echo '<pre>', print_r($term, 1), '</pre>';
        $cats_array[] = $term->term_id;
    }

    echo '<pre>', print_r($cats_array, 1), '</pre>';
	
    $related_posts = get_posts( array(
        'post_type' => 'product',
	'post_status' => 'publish',
	'posts_per_page' => -1,
	'no_found_rows' => 1,
	'post__not_in' => array( $product_id),
	'tax_query' => array( 
	    array(
		'taxonomy' => 'product_cat',
		'field' => 'id',
		'terms' => $cats_array
	    )
	)
    ));
	
    return $related_posts;
}
add_filter( 'woocommerce_related_products', 'my_related_products_by_same_categories', 9999, 3 );

Okay, so this product contains 3 categories
– Dalmatian
– Prints
– Large

Well, in the output you can see that ‘Prints’ is the main category of this product, because the parent => 0. However, “Dalmatian” and “Large” contain a parent ID
so you cannot determine a difference between these. So it won’t work!

The only thing you can try here is to use the first result in the array and ignore the other results.

function my_related_products_by_same_categories( $related_posts, $product_id, $args ) {	
    // get categories
    $terms = wp_get_post_terms( $product_id, 'product_cat' );

    // set array
    $cats_array = [];
	
    foreach ( $terms as $term ) {
        $cats_array[] = $term->term_id;
        break;
    }
	
    $related_posts = get_posts( array(
        'post_type' => 'product',
	'post_status' => 'publish',
	'posts_per_page' => -1,
	'no_found_rows' => 1,
	'post__not_in' => array( $product_id),
	'tax_query' => array( 
	    array(
		'taxonomy' => 'product_cat',
		'field' => 'id',
		'terms' => $cats_array
	    )
	)
    ));
	
    return $related_posts;
}
add_filter( 'woocommerce_related_products', 'my_related_products_by_same_categories', 9999, 3 );

Maybe you should add per product (one) tag that is most applicable to that product and base the code on it, so that only related products with the same tag are shown

It is true that what you are trying to achieve will not be possible, because from your example ‘Prints’ is the main category and therefore not ‘Dalmatian’.

add_filter( 'woocommerce_output_related_products_args', function( $args ) { 
    $args = wp_parse_args( array( 'posts_per_page' => 4 ), $args );
    return $args;
});

add_filter( 'woocommerce_product_related_posts_relate_by_category', function() {
    return false;
});