JezK

Edit File: form-attachment.php

<?php
/**
 * @package ACF
 * @author  WP Engine
 *
 * © 2026 Advanced Custom Fields (ACF®). All rights reserved.
 * "ACF" is a trademark of WP Engine.
 * Licensed under the GNU General Public License v2 or later.
 * https://www.gnu.org/licenses/gpl-2.0.html
 */

if ( ! class_exists( 'acf_form_attachment' ) ) :

class acf_form_attachment {

/**
		 * This function will setup the class functionality
		 *
		 * @type    function
		 * @date    5/03/2014
		 * @since   5.0.0
		 *
		 * @param   n/a
		 * @return  n/a
		 */
		function __construct() {

// actions
			add_action( 'admin_enqueue_scripts', array( $this, 'admin_enqueue_scripts' ) );

// render
			add_filter( 'attachment_fields_to_edit', array( $this, 'edit_attachment' ), 10, 2 );

// save
			add_filter( 'attachment_fields_to_save', array( $this, 'save_attachment' ), 10, 2 );
		}

/**
		 * This action is run after post query but before any admin script / head actions.
		 * It is a good place to register all actions.
		 *
		 * @type    action (admin_enqueue_scripts)
		 * @date    26/01/13
		 * @since   3.6.0
		 *
		 * @param   N/A
		 * @return  N/A
		 */
		function admin_enqueue_scripts() {

// bail early if not valid screen
			if ( ! acf_is_screen( array( 'attachment', 'upload' ) ) ) {
				return;
			}

// load acf scripts
			acf_enqueue_scripts(
				array(
					'uploader' => true,
				)
			);

// actions
			if ( acf_is_screen( 'upload' ) ) {
				add_action( 'admin_footer', array( $this, 'admin_footer' ), 0 );
			}
		}

/**
		 * This function will add acf_form_data to the WP 4.0 attachment grid
		 *
		 * @type    action (admin_footer)
		 * @date    11/09/2014
		 * @since   5.0.0
		 *
		 * @param   n/a
		 * @return  n/a
		 */
		function admin_footer() {

// render post data
			acf_form_data(
				array(
					'screen'  => 'attachment',
					'post_id' => 0,
				)
			);

?>
<script type="text/javascript">
	
// WP saves attachment on any input change, so unload is not needed
acf.unload.active = 0;

</script>
			<?php
		}

/**
		 * description
		 *
		 * @type    function
		 * @date    8/10/13
		 * @since   5.0.0
		 *
		 * @param   $post_id (int)
		 * @return  $post_id (int)
		 */
		function edit_attachment( $form_fields, $post ) {

// vars
			$is_page = acf_is_screen( 'attachment' );
			$post_id = $post->ID;
			$el      = 'tr';

// get field groups
			$field_groups = acf_get_field_groups(
				array(
					'attachment_id' => $post_id,
					'attachment'    => $post_id, // Leave for backwards compatibility
				)
			);

// render
			if ( ! empty( $field_groups ) ) {

// get acf_form_data
				ob_start();

acf_form_data(
					array(
						'screen'  => 'attachment',
						'post_id' => $post_id,
					)
				);

// open
				echo '</td></tr>';

// loop
				foreach ( $field_groups as $field_group ) {

// load fields
						$fields = acf_get_fields( $field_group );

// override instruction placement for modal
					if ( ! $is_page ) {
						$field_group['instruction_placement'] = 'field';
					}

// render
						acf_render_fields( $fields, $post_id, $el, $field_group['instruction_placement'] );
				}

// close
				echo '<tr class="compat-field-acf-blank"><td>';

$html = ob_get_contents();

ob_end_clean();

$form_fields['acf-form-data'] = array(
					'label' => '',
					'input' => 'html',
					'html'  => $html,
				);
			}

// return
			return $form_fields;
		}

/**
		 * description
		 *
		 * @type    function
		 * @date    8/10/13
		 * @since   5.0.0
		 *
		 * @param   $post_id (int)
		 * @return  $post_id (int)
		 */
		function save_attachment( $post, $attachment ) {

// bail early if not valid nonce
			if ( ! acf_verify_nonce( 'attachment' ) ) {
				return $post;
			}

// bypass validation for ajax
			if ( acf_is_ajax( 'save-attachment-compat' ) ) {
				acf_save_post( $post['ID'] );

// validate and save
			} elseif ( acf_validate_save_post( true ) ) {
				acf_save_post( $post['ID'] );
			}

// return
			return $post;
		}
	}

new acf_form_attachment();
endif;