Aggregate Reviews Schema Tags

aggregate-reviews-schema.php

<?php
function display_aggregate_rating() {
	$num_ratings   = 0;
	$agg_score     = 0;
	$args          = array(
		'post_type'      => 'testimonials',
		'posts_per_page' => '-1'
	);
	$testimonials = get_posts( $args );

	foreach ( $testimonials as $testimonial ) {
		$rating = get_post_meta( $testimonial->ID, 'rating', true );
		if ( $rating ) {
			$num_ratings = $num_ratings + 1;
			$agg_score   = $agg_score + $rating;
		}

	}
	$average_score = $agg_score / $num_ratings;

	?>
	<div class="rating" itemscope="" itemtype="http://schema.org/Product">
		<span itemprop="name">Product Name</span>
		<span itemprop="aggregateRating" itemscope="" itemtype="http://schema.org/AggregateRating">
			Rated 
			<span itemprop="ratingValue"><?php echo $average_score; ?></span>
			/5 based on 
			<span itemprop="reviewCount"><?php echo $num_ratings; ?></span>
			customer reviews 
		</span>
	</div>
	<?php
}