While building Lightstorm, my soon to be released custom WordPress theme, I added next and previous links to the bottom of each individual custom post item. In this case I wanted to build a portfolio and to enable the user to click backwards or forwards through the entire portfolio. I added the WordPress next and previous links code thinking it was a nice easy job and then realised that the links were not taking our portfolio custom sorting into account. Oh.

Having googled the problem I couldn’t find exactly what I was looking for so I set about writing some of my own code to fix this and here it is for you to use to.

<?php 
	global $post;
	$prev_title = "";
	$next_title = "";
	
	$args = array(
    'orderby'         => 'menu_order',
    'order'           => 'ASC',
    'post_type'       => 'portfolio',
    'post_status'     => 'publish' ); 
    
	
    $myposts = get_posts( $args );
	$arr = array();
	
	foreach( $myposts as $post ) :	setup_postdata($post); 
		//build array of posts
		$arr[] += $post->ID;		
	endforeach;

	wp_reset_query();

	//find index of current post id in the array
	$currentIndex = array_search($post->ID, $arr);
	$prevIndex = $currentIndex-1;
	$nextIndex = $currentIndex+1;
	$maxNumber = count($arr) - 1;
	
	//show the links
	if($currentIndex != 0){
		$prevID = $arr[$prevIndex];
		$prev_title= "«« ".get_the_title($prevID);
		$prev_permalink = get_permalink($prevID);
	}


	if($currentIndex != $maxNumber){
		$nextID = $arr[$nextIndex];
		$next_title= get_the_title($nextID)." »»";
		$next_permalink = get_permalink($nextID);
	}
	
	echo "<div class='navigation'>";
	echo "<div class='five columns alpha'>";
	echo "<a href='".$prev_permalink."'>".$prev_title."</a>";
	echo "</div>";
	echo "<div class='five columns omega'>";
	echo "<a href='".$next_permalink."'>".$next_title."</a>";
	echo "</div>";
	echo "</div>";
?>

If there is a better way of doing this we’d love to know.