IAP: Custom tag %pr_post_author% for Image Attributes Pro

Custom tag %pr_post_author% for Image Attributes Pro

/**
 * Custom tag %pr_post_author% for Image Attributes Pro
 * 
 * @param $image_id (integer) The ID of the image that is being updated. 
 * @param $parent_post_id (integer) Post to which the image is attached (uploaded) to. 
 * @param $args (array) An array containing additional arguments.
 * 
 * @return (string) Author of the post / page / product if available. Empty string otherwise. 
 * 
 * @refer https://imageattributespro.com/codex/iaffpro_get_custom_attribute_tag_tagname/
 */
function iaffpro_get_custom_attribute_tag_pr_post_author( $image_id, $parent_post_id, $args = array() ) {

	if ( $parent_post_id == 0 ) {
		return '';
	}
	
	$author_id = get_post_field( 'post_author', $parent_post_id );
	$display_name = get_the_author_meta( 'display_name' , $author_id );

	return $display_name;
}