Integrating Post Views Counter stats

It’s possible to integrate all kinds of external data to Relevanssi weights. Post Views Counter is an analytics plugin that collects stats about your visitors and stores them in the local database, which means those stats are available for Relevanssi.

For some sites, this makes a lot of sense. For example, I have Kirjavinkit, a book review site with an archive of about 10,000 book review posts. The popularity of the posts is primarily driven by external search traffic and seems like a good indicator of what users find interesting and valuable.

Integrating the Post Views Counter stats as a factor in the weight calculations is straightforward. The best tool to use is the relevanssi_results filter hook. It lets us modify the weights of the posts. For each post, we calculate a weight multiplier based on the visitor stats and then multiple the weight of the post with that.

I add some normalization here. I normalize all weights to the 1–1,000 range. I also set the minimum weight to 1 to avoid punishing the rarely-visited posts.

To avoid performance problems, I fetch all the stats once and store them in a global variable so that when the function processes all posts, it only needs to make one database request.

Here’s the code:

function rlv_pvc_weight( int $post_id ) : float {
	global $relevanssi_pvc_weights;

	if ( empty( $relevanssi_pvc_weights ) ) {
		global $wpdb;
		$stats = $wpdb->get_results( "SELECT id, count FROM {$wpdb->prefix}post_views WHERE type = 4" );
		foreach ( $stats as $post_stats ) {
			$relevanssi_pvc_weights[ $post_stats->id ] = $post_stats->count;
		}
		$max_visits = max( $relevanssi_pvc_weights );
		$factor     = $max_visits / 1000; // This controls the normalization.
		foreach ( $relevanssi_pvc_weights as $post_id => $visits ) {
			$weight = $visits / $factor;
			if ( $weight < 1 ) {
				$weight = 1;
			}

			$relevanssi_pvc_weights[ $post_id ] = $weight;
		}
	}
	return $relevanssi_pvc_weights[ $post_id ] ?? 1;
}

add_filter( 'relevanssi_results', 'rlv_pvc_weights' );

function rlv_pvc_weights( $post_weights ) {
	foreach ( $post_weights as $post_id => $weight ) {
		$post_weights[ $post_id ] = rlv_pvc_weight( intval( $post_id ) ) * $weight;
	}
	return $post_weights;
}