Hi,
Maybe I’m confused but it seems I cannot figure out how to filter output data for gallery items in admin. Gallery field is not supported as filter in docs acf/fields/...
I’m using WP-Thumb as generator since I use many different image-sizes through out our site. If I look in the source, I find:
// thumbnail
$thumbnail = acf_get_post_thumbnail($a['ID'], 'medium');
And I have no image size called ‘medium’, so the full image is now rendered as gallery thumbnail in admin.
How can I filter the output for a gallery item in admin? Or filter acf_get_post_thumbnail?
“medium” is a default image size added by WP, so that image size should exist unless you’ve somehow removed it. If you need to filter the image that is returned then see https://developer.wordpress.org/reference/hooks/wp_get_attachment_image_src/