• dandolino100

• in reply to: Set a custom field as featured image caption
• August 22, 2022 at 6:18 pm

Support pointed out that there is a typo, but this worked perfectly for me. Fixed typo below:

add_filter('acf/save_post', 'update_featured_image_caption', 20, 1);
function update_featured_image_caption($post_id) {
  // get the featured image id of the post
  $id = get_post_thumbnail_id();
  // if not set, exit
  if (!$id) {
    return;
  }
  // get the field you want to use for the image captions
  $excerpt = get_field('your-field-name', $post_id);
  // if not set, exit
  if (!$excerpt) {
    return;
  }
  // get the attachment post
  $attachment = get_post($id);
  // alter the caption (post_excerpt)
  $attachment->post_excerpt = $excerpt;
  // disable this filter to prevent infinite loop
  remove_filter('acf/save_post', 'update_featured_image_caption', 20);
  // update the attachment post
  wp_update_post($attachment);
  // re-enable this filter
  add_filter('acf/save_post', 'update_featured_image_caption', 20, 1);
}