[Plugin: kk Star Ratings] Upgrade to 2.0 and backward compatibility problem

First thanks for this nice plugin – enjoying it ??

My problem is that after I upgraded to version 2.0, all the ratings on posts are not shown.

I can find the old meta values in the database in the table wp_postmeta.

Now as I read your code it seems as if the problem is focused around the detection of “Old_plugin”.

I was able to manually perform the db upgrade by forcing the following code in a is_admin() within the index.php file. However this is somewhat of a hack – that I doubt many else would be able to perform.

if (is_admin()) {
	echo "this is admin!";
	// Update previous ratings
	global $wpdb;
	$table = $wpdb->prefix . 'postmeta';
	$Posts = $wpdb->get_results("SELECT a.ID, b.meta_key, b.meta_value
								 FROM " . $wpdb->posts . " a, $table b
								 WHERE a.ID=b.post_id AND
								 (
									b.meta_key='_kk_ratings_ratings' OR
									b.meta_key='_kk_ratings_casts' OR
									b.meta_key='_kk_ratings_ips'
								 ) ORDER BY a.ID ASC");
	$Wrap = array();
	foreach ($Posts as $post)
	{
		$Wrap[$post->ID]['id'] = $post->ID;
		$Wrap[$post->ID][$post->meta_key] = $post->meta_value;
	}
	foreach($Wrap as $p)
	{
		update_post_meta($p['id'], '_kksr_ratings', $p['_kk_ratings_ratings']);
		update_post_meta($p['id'], '_kksr_casts', $p['_kk_ratings_casts']);
		$Ips = array();
		$Ips = explode('|', $p['_kk_ratings_ips']);
		$ip = base64_encode(serialize($Ips));
		update_post_meta($p['id'], '_kksr_ips', $ip);
		update_post_meta($p['id'], '_kksr_avg', round($p['_kk_ratings_ratings']/$p['_kk_ratings_casts'],1));
	}
}

https://www.ads-software.com/extend/plugins/kk-star-ratings/