Exclude by category

Found a workaround to override WPP’s query building in functions.php

function op_wpp_exclude_categories($where, $options) {
    global $wpdb;
    
    // Check if we have category exclusion in the options
    if (isset($options['cat']) && !empty($options['cat'])) {
        $categories = explode(',', $options['cat']);
        $exclude_cats = array();
        
        foreach ($categories as $cat) {
            $cat = trim($cat);
            if ($cat < 0) {
                $exclude_cats[] = abs($cat);
            }
        }
        
        // If we have categories to exclude, add our own WHERE clause
        if (!empty($exclude_cats)) {
            $cat_placeholders = implode(',', array_fill(0, count($exclude_cats), '%d'));
            
            $where .= $wpdb->prepare(
                " AND p.ID NOT IN (
                    SELECT DISTINCT tr.object_id 
                    FROM {$wpdb->term_relationships} tr
                    INNER JOIN {$wpdb->term_taxonomy} tt ON tr.term_taxonomy_id = tt.term_taxonomy_id
                    WHERE tt.taxonomy = 'category' AND tt.term_id IN ({$cat_placeholders})
                )",
                $exclude_cats
            );
        }
    }
    
    return $where;
}
add_filter('wpp_query_where', 'op_wpp_exclude_categories', 10, 2);