Featured Image from Gallery via ACF Form

• huwrowlands

• August 23, 2021 at 4:20 pm

Hi,

I am trying to grab the first image from an acf image gallery field on a front end ACF Form and use that as the posts’ Featured Image.

I am using the ‘image array’ return format for the gallery and it is also located within a ‘group’ field.

If anyone can shed some light on my issue it would be most appreciated.

Here is my code in functions.php:

// Create a featured image from the first image in the gallery.
add_filter('acf/save_post', 'gallery_to_thumbnail');
function gallery_to_thumbnail($post_id) {

	if ( have_rows( 'listing_media' ) ) :
		while ( have_rows( 'listing_media' ) ) :
			the_row();
			
			$listing_image_gallery = get_sub_field( 'listing_image_gallery' );
			if ( $listing_image_gallery) :
				$gallery  = get_sub_field( 'listing_image_gallery', false, false );
				$image_id = $gallery[0];
				set_post_thumbnail($post_id, $image_id);				
			endif;
			
		endwhile;
	endif;	
}

• John Huebner

• September 2, 2021 at 5:08 pm

I’m assuming from looking at your code that “listing_media” is the repeater.

if this is inside a group field then you also need to loop over the group field.

You also need to supply the post ID inside of the function for the first field.

if (have_rows('group_field_name', $post_id)) {
  while (have_rows('group_field_name', $post_id)) {
    the_row();
    if (have_rows('listing_media')) {
      while (have_rows('listing_media')) {
        the_row();
        $gallery  = get_sub_field('listing_image_gallery', false, false);
        // etc
      }
    }
  }
}

• huwrowlands

• September 3, 2021 at 1:04 pm

Actually, the ‘listing_media’ is the group field. What resolved my issue was adding $post_id to the the end of ‘listing_media’.

if (have_rows('listing_media', $post_id)) {
      while (have_rows('listing_media', $postId)) {

Thank you