WordPress related post by tag

related-tag.php

<?php
/!**
* WordPress related post by tag
* @author: takien
*/

$all_tags = get_the_tags();
$tags = Array();
if($all_tags) {
foreach($all_tags as $rel_tag) {
	$tags[] = $rel_tag->term_id;
}
}
$current_post_id = get_the_ID();

if(!empty($tags)) {
?>
<ul>
<?php
	$arg = Array(
	'posts_per_page'=>10,
	'tag__in'       => $tags,
	'post__not_in'  => Array($current_post_id)
	);
	$query = new WP_Query($arg);
	if( $query->have_posts() ) 
	while($query->have_posts()) : $query->the_post();
	?>
	<li>
		<a href="<?php the_permalink();?>"><?php the_title();?></a>
	</li>
			
	<?php endwhile;?>
</ul>
<?php
}
?>