Using custom variable in Bulk E-mails

[nrep]

I need to use some basic hashing in bulk e-mails, which I can do with {xen:calc} in the e-mail body - however this doesn't appear to work.

I had a look at user.php in library/XenForo/ControllerAdmin and found this fucntion:

protected function _sendEmail(array $user, array $email, Zend_Mail_Transport_Abstract $transport)

It seems to run through the 3 replacements mentioned on the bulk e-mail page:

$replacements = array(
'{name}' => htmlspecialchars($user['username']),
'{email}' => htmlspecialchars($user['email']),
'{id}' => $user['user_id']
);

Is there a way I can add my own replacement in there via an addon without modifying the core code?

 

[nrep]

I've been trying to get this working all day and I've read up on extending even listeners, but I don't really understand it yet.

I have created an event listener for "load class" with an event hint of "XenForo_ControllerAdmin_User" and callback "customaddon_Listener_LoadClass::_sendEmail"

In customaddon/Listener/LoadClass.php I've got:

<?php

class customaddon_Listener_LoadClass
{
  public static function _sendEmail($class, &$extend)
  {

  if ($class == 'XenForo_ControllerAdmin_User')
  {
  $extend[] = 'customaddon_Extend_XenForo_ControllerAdmin_User';
  }

  }

}

Then, in customaddon/Extend/XenForo/Controller/Admin/user.php I've got part of the default XF user.php file, starting like this:

<?php

/**
*
* @see XenForo_ControllerAdmin_User
*/
class customaddon_Extend_XenForo_ControllerAdmin_User extends XFCP_customaddon_Extend_XenForo_ControllerAdmin_User
{

  protected function _sendEmail(array $user, array $email, Zend_Mail_Transport_Abstract $transport)

I've then added in my hash replacement, i.e.:

  $replacements = array(
  '{name}' => htmlspecialchars($user['username']),
  '{email}' => htmlspecialchars($user['email']),
  '{id}' => $user['user_id'],
  '{hash}' => 'xxxx' 
  );

However, when I do a test send {hash} isn't replaced. I'm sure I've done something wrong when trying to extend things, as I've never done this before, but I can't get my head round it. Am I far off?