wordpress: Bootstrap 4.1 pagination

gistfile1.txt

/* Bootstrap pagination.
=========================================================================== */
function itl_paging_nav() {
    global $wp_query, $wp_rewrite;

    // Setting up default values based on the current URL.
    $pagenum_link = html_entity_decode( get_pagenum_link() );
    $url_parts    = explode( '?', $pagenum_link );

    // Get max pages and current page out of the current query, if available.
    $total   = isset( $wp_query->max_num_pages ) ? $wp_query->max_num_pages : 1;
    $current = get_query_var( 'paged' ) ? intval( get_query_var( 'paged' ) ) : 1;

    // Append the format placeholder to the base URL.
    $pagenum_link = trailingslashit( $url_parts[0] ) . '%_%';

    // URL base depends on permalink settings.
    $format  = $wp_rewrite->using_index_permalinks() && ! strpos( $pagenum_link, 'index.php' ) ? 'index.php/' : '';
    $format .= $wp_rewrite->using_permalinks() ? user_trailingslashit( $wp_rewrite->pagination_base . '/%#%', 'paged' ) : '?paged=%#%';

    $args = array(
        'base'               => $pagenum_link,
        'format'             => $format,
        'total'              => $total,
        'current'            => $current,
        'prev_text'          => __( '« Previous' ),
        'next_text'          => __( 'Next »' ),
        'end_size'           => 1,
        'mid_size'           => 2,
        'type'               => 'array',
        'add_args'           => false,
    );

    $pages = paginate_links( $args );

    if ( ! $pages ) {
        return;
    }
 
    if ( $total < 2 ) {
        return;
    }

    $pagination = '<div class="pagination"><ul class="pagination">';

    foreach ( $pages as $page ) {
        $pagination .= sprintf( '<li class="page-item %s">%s</li>',
            strpos ( $page, 'current' ) !== false ? 'active' : '',
            str_replace( 'page-numbers', 'page-link', $page )
        );
    }

    $pagination .= '</ul></div>';

    echo $pagination;
}