hook help - prevent $0 invoice

[MBayDesign]

I've got a product setup to establish Quarterly Maintenance service using autorelease, $0.00 quarterly and an email marketing rule that spits out a reminder that maintenance will be performed based on the due date. I then invoice manually because it's different every time.

 

The marketing rule portion works great, but I'm obviously trying to prevent the $0 invoice from being sent and support directed me to the EmailPreSend hook. (I'm still not sure why preventing $0 invoices isn't baked into WHMCS as an option, but it's obviously not.)

 

I have fumbled with various iterations of code, including using this portion to select from the DB which I found here:

 

$result = select_query('tblinvoices', 'total', array("id" => $relid));
      $data = mysql_fetch_assoc($result);
      //if it is equal to '0.00' we disable email sending
      if (isset($data['total']) && $data['total'] == '0.00')

 

All my choices were wildly incorrect. This is another version that also didn't work:

 

<?php

add_hook('EmailPreSend', 1, function($vars) {
   $merge_fields['invoice_total'] = "$0.00";
   if ($vars['messagename'] =='Credit Card Invoice Created' && $vars['relid'] == 22) {
       //Stop the email from sending a specific message and related id.
       $merge_fields['abortsend'] = true;
   }
   return $merge_fields;
});

 

I had hopes, but this didn't work either. This seems like it should be such a simple code, but I’m obviously missing something…

 

Help most appreciated - thanks!

[MBayDesign]

Well, perhaps the lack of response is that the hook works, the one that's linked to; however, when I tried it before, it hosed my site. So, after a slight edit, problem solved and the link to the hook noted does work.