WooCommerce: Get average rating from multiple products [duplicate]

Question

I've a custom loop to get a list of products based on a list of product IDs. Now I try to get the total ratings and average rating of all the products within that loop.

The total count of ratings isn't the problem. My problem is that I don't get the star rating from the comments. (I'm using the plugin "WooCommerce Product Reviews Pro")

Here's my current loop so far:

<?php $args = array (
    'post_type' => 'product',
    'number'  => '-1',
    'post__in' => $product_ids,
    'meta_key' => 'rating',
    'orderby' => 'meta_value_num',
    'order' => 'DESC'
);
$comments = get_comments( $args );

echo count($comments);
?>
<?php if ( !empty($comments) ) : ?>
    <pre><?php print_r($comments); ?></pre>

    <?php foreach ( $comments as $comment ) {

        echo $comment_ID = $comment->comment_ID;

    } ?>

<?php endif; ?>

With echo count($comments) I get the total count of ratings.

But if I do print_r($comments), I don't see the star rating for the review.

I guess that I need to use the comment ID for that.

With the foreach I get all comment Ids as a string.

But I'm not sure where to look and how I add all ratings to generate a new average rating for the selected posts from the loop.

EDIT: I found another way to get to the average ratings. This time I loop through the posts instead the comments.

So I can get the average rating for every product.

The problem is that in that loop are also ratings with a 0 if there are no comments/reviews.

Here's the loop for the product so far:

$average_ratings = array();

foreach ( $posts as $post ) {

    global $product;
    echo $average_ratings[] = $product->get_average_rating();

}

var_dump($average_ratings);

Answer 1

I found an answer. This is my code:

<?php
$args = array (
    'post_type' => 'product',
    'post__in' => $product_ids,
    'meta_key' => 'rating',
    'orderby' => 'meta_value_num',
    'order' => 'DESC'
);
$comments = get_comments( $args );

$total_ratings = count($comments);
?>
<?php if ( !empty($comments) ) : ?>

    <?php
    $average_ratings = array();
    foreach ( $comments as $comment ) {
        $comment_post_ID = $comment->comment_post_ID;
        $product = wc_get_product( $comment_post_ID );
        $average_ratings[] = $product->get_average_rating();
    }

    $average_ratings = array_filter($average_ratings);
    $average = array_sum($average_ratings)/count($average_ratings);
    echo $average;
    ?>

<?php endif; ?>