Show Related Post in WordPress Without a Plugin

Related posts is a very popular feature. My default wordpress installation often includes a plugin that has this functionality. There are quite a few plugins that lets you have this feature



WordPress has been supporting tags in its new released – so the related posts feature can be implemented without the help of any plugins. All we have to do is find the other posts with some same tags as the current post. Just open the single.php file in your theme and add this bit of code where you want the related posts to show up…

$tags = wp_get_post_tags($post->ID);
if ($tags) {
	$tag_ids = array();
	foreach($tags as $individual_tag) $tag_ids[] = $individual_tag->term_id;

	$args=array(
		'tag__in' => $tag_ids,
		'post__not_in' => array($post->ID),
		'showposts'=>5, // Number of related posts that will be shown.
		'caller_get_posts'=>1
	);
	$my_query = new wp_query($args);
	if( $my_query->have_posts() ) {
		echo '


Related Posts
';
		while ($my_query->have_posts()) {
			$my_query->the_post();
		?>

';
	}
}

This code finds the other post with any one of the tag that the current post has. If you want to show the posts with any one of the categories that the current post has, use this code instead…

$categories = get_the_category($post->ID);
if ($categories) {
	$category_ids = array();
	foreach($categories as $individual_category) $category_ids[] = $individual_category->term_id;

	$args=array(
		'category__in' => $category_ids,
		'post__not_in' => array($post->ID),
		'showposts'=>5, // Number of related posts that will be shown.
		'caller_get_posts'=>1
	);
	// Rest is the same as the previous code

If this code put before comments or anthing, before use it , you should call wp_reset_query() function.