I have a category called "Featured Photo" that is category ID 2. I want to create next-post and previous-post links that contain links only for the next and previous posts in category ID 2. However, many "Featured Photo" posts also belong to more than one category, and I have so far been unable to find a solution that limits the "Next" and "Previous" links to category 2. If I do not exclude any categories in the previous_post_link() and next_post_link() calls, those links are populated with the URL to the previous/next post in one of the other multiple categories assigned to the "Featured Photo" posts. Thus, I created a variable containing an array of all of the other category IDs and added it to the exclude portion of the previous_post_link() and next_post_link() calls, but that is just resulting in the links not showing up at all. (I've searched extensively for a solution, and haven't found anything that works.)
function featured_photo() {
global $post;
if (is_single() && in_category(2)) {
$category = array(1,3,4,5,6,7,8,9,67,68,69,74,76,78,82);
$pod = get_post_meta($post->ID, 'pod', true);
echo '<div id="pod">';
echo the_title( '<h1 class="entry-title">', '</h1>' );
echo $pod;
previous_post_link( '%link', 'Previous photo', true, $category );
next_post_link( '%link', 'Next photo', true, $category );
echo '</div>';
}
}
add_action( 'genesis_before_content','featured_photo');