felixarntz/attachment-taxonomies-feature

<?php
/**
 * @package AttachmentTaxonomiesFeature
 */

/**
 * Sets terms for attachment taxonomies through the `save_attachment` AJAX action.
 *
 * This is a workaround to handle terms through this AJAX action as it normally does not support
 * terms.
 *
 * @param int $attachment_id The attachment ID.
 */
function atf_save_ajax_attachment_taxonomies( $attachment_id ) {
    if ( ! doing_action( 'wp_ajax_save-attachment' ) ) {
        return;
    }

    if ( empty( $_REQUEST['changes'] ) ) {
        return;
    }

    foreach ( get_object_taxonomies( 'attachment', 'objects' ) as $taxonomy ) {
        if ( ! isset( $_REQUEST['changes'][ 'taxonomy-' . $taxonomy->name . '-terms' ] ) ) {
            continue;
        }

        $terms = $_REQUEST['changes'][ 'taxonomy-' . $taxonomy->name . '-terms' ];
        if ( $taxonomy->hierarchical ) {
            $terms = array_filter( array_map( 'trim', explode( ',', $terms ) ) );
        }

        if ( current_user_can( $taxonomy->cap->assign_terms ) ) {
            wp_set_post_terms( $attachment_id, $terms, $taxonomy->name );
        }
    }
}