I found a few articles with examples on how to achieve this, but they don't output any data for me. Here's an example:
function woo_products_by_tags_shortcode( $atts, $content = null ) {
// Get attribuets
extract(shortcode_atts(array(
"tags" => ''
), $atts));
ob_start();
// Define Query Arguments
$args = array(
'post_type' => 'product',
'posts_per_page' => 5,
'product_tag' => $tags
);
// Create the new query
$loop = new WP_Query( $args );
// Get products number
$product_count = $loop->post_count;
// If results
if( $product_count > 0 ) :
echo '<ul class="products">';
// Start the loop
while ( $loop->have_posts() ) : $loop->the_post(); global $product;
global $post;
echo "<p>" . $thePostID = $post->post_title. " </p>";
if (has_post_thumbnail( $loop->post->ID ))
echo get_the_post_thumbnail($loop->post->ID, 'shop_catalog');
else
echo '<img src="'.$woocommerce->plugin_url().'/assets/images/placeholder.png" alt="" width="'.$woocommerce->get_image_size('shop_catalog_image_width').'px" height="'.$woocommerce->get_image_size('shop_catalog_image_height').'px" />';
endwhile;
echo '</ul><!--/.products-->';
else :
_e('No product matching your criteria.');
endif; // endif $product_count > 0
echo ob_get_clean();
}
This code is a shortcode, and I don't want to have to write one out and input the tag name manually. I want to use this function to hook into woocommerce_after_single_product_summary. Basically I'm trying to achieve 
.
The first post is the current post. After that it's up to 3 more posts that will be visible. The query needs to look at the current product's tag, find more in it, and output ordered by the product category.
