It turns out you can call acf_update_field with almost the same parameters as acf_add_local_field, except I just had to pass the parent as a post_id. Here’s the (simplified) code that I used:
function get_acf_group_id($group_name){
global $wpdb;
return $wpdb->get_var("
SELECT ID
FROM $wpdb->posts
WHERE post_type='acf-field-group' AND post_excerpt='$group_name';
");
}
function my_field_registration( $value, $post_id, $field ) {
if ( $field['name'] == 'my_triggering_field' ) {
if ( $some_condition ) {
$args = array(
'key' => 'field_' . uniqid();,
'label' => 'Field label',
'name' => 'my_new_field_name',
'type' => 'number',
'parent' => get_acf_group_id('my-field-group-name') // hyphenated!
);
acf_update_field($args);
}
}
return $value;
}
add_filter('acf/update_value', 'my_field_registration', 10, 3);
This creates a field programmatically in the database which is editable in the admin.
