在循环中显示自定义帖子类型（特别是该帖子）的WordPress类别

Question

I'm using a Javascript filter which shows and hide a list (loop) of Custom Post Types based on their category.

I'm trying to add the category slug as a class. But I only want to display the categories that are assigned to a specific loop item. Each item can have multiple categories.

I've done it this way, but it dumps all the categories on each loop, not ones specifically for that loop item.

<?php
    $pageID = get_the_ID();
    $loop = new WP_Query(array('post_type' => 'casestudies', 'posts_per_page' => -1));
    $taxonomy = 'custom_casestudies';
    $terms = get_terms($taxonomy);
    while ($loop->have_posts()) : $loop->the_post();
?>

<div class="block-wrap mix <?php foreach ($terms as $term) echo  ' ' . $term->slug; ?>">
    // loop content
</div>

<?php endwhile; wp_reset_postdata(); ?>

Answer 1

get_terms returns all of the terms in the given taxonomy. In this case you should be using wp_get_post_terms, which returns a list of terms for a given post. The documentation goes into more detail.

Answer 2

In case this helps anyone else and thanks to Matt (who answered) this is working.

<?php
    global $post;
    $loop = new WP_Query(array('post_type' => 'casestudies', 'posts_per_page' => -1));
    while ($loop->have_posts()) : $loop->the_post();
    $terms = wp_get_post_terms($post->ID, 'custom_casestudies');
?>
<div class="block-wrap mix<?php foreach ($terms as $term) echo  ' ' . $term->slug ?>">
    // content
</div>

<?php endwhile; wp_reset_postdata(); ?>

The terms have been to be after the while loop.