Numbered siblings (child page navigation)

functions-1424101035.php

<?php
// the menu_order parameter has been added to account for custom page ordering
function numbered_siblings($link) {
	global $post;
	$siblings = get_pages('child_of=' . $post->post_parent . '&parent=' . $post->post_parent . '&sort_column=menu_order');
	foreach($siblings as $key=>$sibling) {
		if($post->ID == $sibling->ID) {
			$ID = $key;
		}
	}
	$closest = array(
		'before' => get_permalink($siblings[$ID-1]->ID),
		'after' => get_permalink($siblings[$ID+1]->ID)
	);

	if($link == 'before' || $link == 'after') {
		return $closest[$link];
	}
	else {
		return $closest;
	}
}
function numbered_navigation($parent, $previous, $next) {
	global $post;

	$post_slug = $post->post_name;
	$count = 0; $current = 0;
	$pages = get_pages('child_of=' . $parent . '&depth=1&sort_column=menu_order');
	$out = '';

	$out .= '<div class="navigation">
		<a href="' . numbered_siblings('before') . '">' . $previous . '</a>
		<a href="' . numbered_siblings('after') . '">' . $next . '</a>
		<div class="page-index">';

		foreach($pages as $page) {
			$count++;
			if($post_slug == $page->post_name)
				$current = $count;
		}

		$out .= $current . '/' . $count;
	$out .= '</div>
	</div>';

	return $out;
}

// Usage
echo numbered_navigation('', 'Previous', 'Next');
?>