Add a Copyright Field to the Media Uploader in WordPress

When you upload something into WordPress using the Media Uploader, you can include information such as a caption or a description. If you wanted to include something else, you would first have to create a custom field by hooking into the attachment_fields_to_edit filter. I decided to add a “Copyright” field so that I could credit each item I upload to the original copyright owner and displayed on the front end wherever I want.

Here is the code you need to add to your functions.php file:

/**
 * Adding a "Copyright" field to the media uploader $form_fields array
 *
 * @param array $form_fields
 * @param object $post
 *
 * @return array
 */
function add_copyright_field_to_media_uploader( $form_fields, $post ) {
	$form_fields['copyright_field'] = array(
		'label' => __('Copyright'),
		'value' => get_post_meta( $post->ID, '_custom_copyright', true ),
		'helps' => 'Set a copyright credit for the attachment'
	);

	return $form_fields;
}
add_filter( 'attachment_fields_to_edit', 'add_copyright_field_to_media_uploader', null, 2 );

/**
 * Save our new "Copyright" field
 *
 * @param object $post
 * @param object $attachment
 *
 * @return array
 */
function add_copyright_field_to_media_uploader_save( $post, $attachment ) {
	if ( ! empty( $attachment['copyright_field'] ) ) 
		update_post_meta( $post['ID'], '_custom_copyright', $attachment['copyright_field'] );
	else
		delete_post_meta( $post['ID'], '_custom_copyright' );

	return $post;
}
add_filter( 'attachment_fields_to_save', 'add_copyright_field_to_media_uploader_save', null, 2 );

/**
 * Display our new "Copyright" field
 *
 * @param int $attachment_id
 *
 * @return array
 */
function get_featured_image_copyright( $attachment_id = null ) {
	$attachment_id = ( empty( $attachment_id ) ) ? get_post_thumbnail_id() : (int) $attachment_id;

	if ( $attachment_id )
		return get_post_meta( $attachment_id, '_custom_copyright', true );

}

With the above code in place, you can now use the following snippet to display your attachment’s new “Copyright” field within one of your page templates.

<?php echo get_featured_image_copyright(); ?>

If you leave the attachment ID parameter blank, it will display the featured image “Copyright” if your post has a featured image set.