I might be a bit off with this, but I ran into what I think is a similar issue. I look for an empty field (video thumbnail in my case), and if it’s empty, I look at another field (a vimeo video ID) and I do a little fetch of some json to grab the thumbnail URL and then save it. This has worked great for simple ACF fields.
I recently wanted to use this in a Group, and noticed the field wasn’t updating.
I had a few problems:
– I was using ‘acf/update_value/name=thumbnail_url’ which will match any field (including subfields it turns out) with that name. Cool for most of my other ACFs where I can just have one filter in functions.php to cover a bunch of different ACF fields where I need this. Not cool for this subfield, as the video ID was also in a subfield, so my function was not finding a video ID.
– I had no idea how to match a subfield in the “acf/update_value/name=foobar” format (still don’t)
– I had no idea how to fetch the subfield with the video ID
This was the original function/filter:
// Fetch vimeo thumbnail on save - takes video ID as input
function rf_acf_update_vimeo_thumb( $value, $post_id, $field ) {
// only set a new value if the field is empty
if ( $value == '') {
// get video here
$vimeo_video_id = get_field('vimeo_video_id');
// fetch thumb url(s)
$vimeo_meta = file_get_contents("https://vimeo.com/api/v2/video/$vimeo_video_id.json");
$vimeo_meta = json_decode($vimeo_meta);
$vimeo_thumb = $vimeo_meta[0]->thumbnail_large;
// set value
$value = $vimeo_thumb;
return $value;
} else {
return $value;
}
}
add_filter('acf/update_value/name=thumbnail_url', 'rf_acf_update_vimeo_thumb', 10, 3);
So to “fix” this:
– I opted to give my thumbnail field a new name since I don’t know how to match on a subfield only, so that’s now “wfh_thumbnail_url”.
– I randomly stumbled on another post in these forums that stated a subfield can be fetched by combining the group’s field name and the subfield name, so my “get_field()” for the video ID which is in the group “page_top” and is named “vimeo_video_id” is fetched with “get_field(‘page_top_vimeo_video_id’);”
With those two changes, things seem to work well.
// same, but sub-field
// Fetch vimeo thumbnail on save - takes video ID as input
function rf_acf_update_vimeo_thumb_alt( $value, $post_id, $field ) {
// only set a new value if the field is empty
if ( $value == '') {
// get video here
$vimeo_video_id = get_field('page_top_vimeo_video_id');
// fetch thumb url(s)
$vimeo_meta = file_get_contents("https://vimeo.com/api/v2/video/$vimeo_video_id.json");
$vimeo_meta = json_decode($vimeo_meta);
$vimeo_thumb = $vimeo_meta[0]->thumbnail_large;
// set value
$value = $vimeo_thumb;
return $value;
} else {
return $value;
}
}
add_filter('acf/update_value/name=wfh_thumbnail_url', 'rf_acf_update_vimeo_thumb_alt', 10, 3);
I do wish I could just match with ‘acf/update_value/name=page_top_wfh_thumbnail_url’…
