sort post by monthly views

Hi there!

Based on something I played with a long time ago, here’s a revised version that should do what you need:

add_action( 'pre_get_posts', 'sort_by_most_viewed' );

function sort_by_most_viewed( $query ){
    global $wp_query;

    // Run this only on the front-end, leave the admin side alone
    if ( !is_admin() && $query->is_main_query() ) {

        // Ignore sticky posts
        $query->set( 'ignore_sticky_posts', true );

        add_filter( 'posts_fields', 'wpp_query_fields' );
        add_filter( 'posts_join', 'wpp_query_join' );
        add_filter( 'posts_where' , 'wpp_query_where' );
        add_filter( 'posts_groupby', 'wpp_query_group_by' );
        add_filter( 'posts_orderby', 'wpp_query_order_by' );

    }

}

function wpp_query_fields( $fields ){
    global $wpdb;

    $fields .= ", SUM({$wpdb->prefix}popularpostsdata.pageviews) AS pageviews";

    return $fields;
}

function wpp_query_join( $join ){
    global $wpdb;

    $join .= " LEFT JOIN {$wpdb->prefix}popularpostssummary ON " . $wpdb->posts . ".ID = {$wpdb->prefix}popularpostssummary.postid ";

    return $join;
}

function wpp_query_where( $where ){
    global $wpdb;

    $now = current_time('mysql');
    $where .= " AND {$wpdb->prefix}popularpostssummary.last_viewed > DATE_SUB('{$now}', INTERVAL 1 MONTH) ";

    return $where;
}

function wpp_query_group_by( $groupby ){
    global $wpdb;

    $groupby = "{$wpdb->prefix}popularpostssummary.postid";

    return $groupby;
}

function wpp_query_order_by( $orderby ){
    return "pageviews DESC";
}

I didn’t test this, though. Give it a try and let me know how it goes, alright?