WordPress - Bootstrap 4 pagination

bootstrap-pagination.php

<?php
/**
 * Template for displaying bootstrap 4 post pagination.
 *
 * @package    WordPress
 * @subpackage Bootstrap
 * @author     Milan Arandjelovic
 */

if ( ! function_exists( 'bootstrap_pagination' ) ) {
	/**
	 * Return HTML for bootstrap 4 pagination.
	 *
	 * @since 1.0.0
	 * @param  array $args Array of arguments.
	 */
	function bootstrap_pagination( $args = array() ) {
		global $wp_query;

		$defaults = array(
			'range' => 4,
			'custom_query' => false,
			'previous_string' => __( 'Previous', 'bootstrap' ),
			'next_string' => __( 'Next', 'bootstrap' ),
			'before_output' => '<nav><ul class="pagination">',
			'after_output' => '</ul></nav>',
		);

		$args = wp_parse_args(
			$args,
			apply_filters( 'bootstrap_pagination_defaults', $defaults )
		);

		$args['range'] = (int) $args['range'] - 1;

		if ( ! $args['custom_query'] ) {
			$args['custom_query'] = $wp_query;
		}

		$count = (int) $args['custom_query']->max_num_pages;
		$page = intval( get_query_var( 'paged' ) );
		$ceil = ceil( $args['range'] / 2 );

		if ( $count <= 1 ) {
			return false;
		}

		if ( ! $page ) {
			$page = 1;
		}

		if ( $count > $args['range'] ) {
			if ( $page <= $args['range'] ) {
				$min = 1;
				$max = $args['range'] + 1;
			} elseif ( $page >= ( $count - $ceil ) ) {
				$min = $count - $args['range'];
				$max = $count;
			} elseif ( $page >= $args['range'] && $page < ( $count - $ceil ) ) {
				$min = $page - $ceil;
				$max = $page + $ceil;
			}
		} else {
			$min = 1;
			$max = $count;
		}

		$pagination = '';
		$previous = intval( $page ) - 1;
		$previous = esc_attr( get_pagenum_link( $previous ) );

		$first_page = get_pagenum_link( 1 );

		if ( $first_page && ( 1 !== $page ) ) {
			$pagination .= '<li class="page-item"><a href="' . $first_page . '" class="page-link">' . __( '<i class="fa fa-angle-double-left"></i>', 'bootstrap' ) . '</a></li>';
		}

		if ( $previous && ( 1 !== $page ) ) {
			$pagination .= '<li class="page-item"><a href="' . $previous . '" class="page-link" title="' . __( 'previous', 'bootstrap' ) . '">' . $args['previous_string'] . '</a></li>';
		}

		if ( ! empty( $min ) && ! empty( $max ) ) {
			for ( $i = $min; $i < $max; $i++ ) {
				if ( $page === $i ) {
					// Active class.
					$pagination .= '<li class="page-item active"><a class="page-link">' . str_pad( (int) $i, 1, '0', STR_PAD_LEFT ) . '</a></li>';
				} else {
					$pagination .= sprintf( '<li class="page-item"><a href="%s" class="page-link">%d</a></li>', esc_attr( get_pagenum_link( $i ) ), $i );
				}
			}
		}

		$next = intval( $page ) + 1;
		$next = esc_attr( get_pagenum_link( $next ) );

		if ( $next && ( $count !== $page ) ) {
			$pagination .= '<li class="page-item"><a href="' . $next . '" class="page-link" title="' . __( 'next', 'bootstrap' ) . '">' . $args['next_string'] . '</a></li>';
		}

		$last_page = esc_attr( get_pagenum_link( $count ) );

		
		if ( $last_page && ( $count !== $page ) ) {
			$pagination .= '<li class="page-item"><a href="' . $last_page . '" class="page-link">' . __( '<i class="fa fa-angle-double-right"></i>', 'phoenix' ) . '</a></li>';
		}

		if ( $last_page && ( $count === $page ) ) {
			$pagination .= '<li class="page-item active"><a href="' . $last_page . '" class="page-link">' . $count . '</a></li>';
		}
		
		if ( isset( $pagination ) ) {
			echo $args['before_output'] . $pagination . $args['after_output'];
		}
	}
}