Problem migrating from Smarty 2 to Smarty 3?

Question

PHP

The question is quite simple, I can not transfer the script to the new version of the template engine.
I used to have this code

function emailtpl_template($tpl_name, &$tpl_source, Smarty $smarty_obj)
{
  $tpl_source = $smarty_obj->get_template_vars($tpl_name);
  return empty($tpl_source) ? false : true;
}

function emailtpl_timestamp($tpl_name, &$tpl_timestamp, Smarty $smarty_obj)
{
  return true;
}

function emailtpl_secure($tpl_name, Smarty $smarty_obj)
{
  return true;
}

function emailtpl_trusted($tpl_name, Smarty $smarty_obj)
{
}

$smarty = new Smarty();
$smarty->compile_id = md5($subject . $message . (defined("IN_CRON") ? "cron" : ""));
$smarty->register_resource("emailtpl", array("emailtpl_template", "emailtpl_timestamp", "emailtpl_secure", "emailtpl_trusted"));
$smarty->assign("emailsubject", $subject);
$smarty->assign("emailmessage", $message);
$smarty->assign("plaintext", $message_text);

foreach ($email_merge_fields as $mergefield => $mergevalue) {
  $smarty->assign($mergefield, $mergevalue);
}

$subject = $smarty->fetch("emailtpl:emailsubject");
$message = $smarty->fetch("emailtpl:emailmessage");
$message_text = $smarty->fetch("emailtpl:plaintext");

But in Smarty 3, the register_resource function was changed to registerResource,
I replaced it in my code, but the script began to give me an error

Fatal error: Uncaught --> Smarty: Unable to load template emailtpl 'emailsubject' <-- thrown in W:\domains\test\Smarty\sysplugins\smarty_internal_template.php on line 138

But before the transition, everything worked. tell me what to do to get started.

Answer 1

In Smarty 3, the registerResource method no longer accepts an array of functions.
It now accepts a successor to the abstract Smarty_Resource class.
www.smarty.net/docs/en/api.register.resource.tpl

Answer 2

$smarty->registerResource("emailtpl", array("emailtpl_template", "emailtpl_timestamp", "emailtpl_secure", "emailtpl_trusted"));

In the 6th version of WHMCS, they changed the environment
. As a result, you need to specify as the second parameter not a string array, but an array of resource objects, does anyone know which resources to specify?