Get data of a Caldera Forms multiple files field and save the files in an ACF gallery custom field

cf-save-file_field-as-acf-gallery.php

<?php
/*
 * This function is copied from https://wpscholar.com/blog/get-attachment-id-from-wp-image-url/
 *
 *  Function to get the attachment ID of a media file based on its URL in WordPress
 *
 */
function get_attachment_id( $url ) {
    $attachment_id = 0;
    $dir = wp_upload_dir();
    if ( false !== strpos( $url, $dir['baseurl'] . '/' ) ) { // Is URL in uploads directory?
        $file = basename( $url );
        $query_args = array(
            'post_type'   => 'attachment',
            'post_status' => 'inherit',
            'fields'      => 'ids',
            'meta_query'  => array(
                array(
                    'value'   => $file,
                    'compare' => 'LIKE',
                    'key'     => '_wp_attachment_metadata',
                ),
            )
        );
        $query = new WP_Query( $query_args );
        if ( $query->have_posts() ) {
            foreach ( $query->posts as $post_id ) {
                $meta = wp_get_attachment_metadata( $post_id );
                $original_file       = basename( $meta['file'] );
                $cropped_image_files = wp_list_pluck( $meta['sizes'], 'file' );
                if ( $original_file === $file || in_array( $file, $cropped_image_files ) ) {
                    $attachment_id = $post_id;
                    break;
                }
            }
        }
    }
    return $attachment_id;
}
/*
 *  Transform data from file field and update gallery custom field
 *
 */
add_action( 'caldera_forms_submit_complete', function( $form, $referrer, $process_id, $entryid ) {

    //change your form ID here
    if( 'CF5a5e8452c6f82' != $form[ 'ID' ] ) {
        return;
    }
    //change your field ID here
    $imgs = Caldera_Forms::get_field_data( 'fld_6467937', $form );
    $attachments_array = array();
    if( !empty($imgs) ) {
        foreach( $imgs as $img_url ){
            $img_id = get_attachment_id( $img_url );
            $attachments_array[] = $img_id;
        }
    }
    //Change the field ID of the hidden field using {post_type:ID} magic tag as value
    $pid = Caldera_Forms::get_field_data( 'fld_6098178', $form );
    $post_id = Caldera_Forms::do_magic_tags( $pid, $entryid );

    //Update the ACF custom field ID
    if( !empty( $attachments_array ) && !empty( $post_id ) { 
      update_field( 'field_0000000000', $attachments_array , $post_id );
    }

}, 10, 4 );