disable_invoice_notification.php

<?php
/*
 * disable_invoice_notification.php
 * 
 * Version 1.0 
 * 
 * An action hook for WHMCS that allows you to disable sending of invoice reminders for selected payment methods.
 *
 * To install:
 *  - Set the array of payment methods that should not send invoice reminders. Typically debit order / direct debit.
 *  - The other array is a list of reminders that should not be sent.
 *  - Then place this script in your whmcs/includes/hooks/ directory.
 *  - Optionally specifiy a log file location.
 * 
 * Based on Reed Murphy's work at https://gist.github.com/RWJMurphy/3ee801306f2cfca79d61b38041dcdaed
 * 
 * By: Eugene van der Merwe ([email protected]) +27823096710 I create WHMCS magic and I'm available for consulting
 *
 */

function hook_disable_invoice_notification($vars) {
    // If $logfile is not blank, messages about emails not sent will be logged to this file.
    // $logfile = "/home/whmcs/presendemail.log";
    // $logfile = "";

    // An array of IDs of payment methods that should not receive invoice notification emails. Replace these with your own.
    $gateway_names = Array(
        "debitizedo", // Netcash x-Sage
        // "directdebit", // Add an array of payment methods that should not send payment reminders
    );

    // The names of the email templates that you don't want sent.
    $message_names = Array(
        "First Invoice Overdue Notice",
        "Second Invoice Overdue Notice",
        "Third Invoice Overdue Notice",        
    );

    $merge_fields = array();

    if (in_array($vars['messagename'], $message_names)) {
        $invoice_id = mysql_real_escape_string($vars['relid']);

        $query =
            "SELECT `userid`, CONCAT_WS(' ', `firstname`, `lastname`) as 'name', paymentmethod, tblinvoices.id ".
            "FROM `tblinvoices` ".
            "JOIN `tblclients` ON `tblinvoices`.`userid` = `tblclients`.`id` ".
            "WHERE `tblinvoices`.`id` = '" . $invoice_id ."'";

        $r = full_query($query);

        if ($r) {
            $row = mysql_fetch_row($r);
            $client_id = $row[0];
            $client_name = $row[1];
	          $payment_method = $row[2];
	          $invoice_id = $row[3];

            if ( in_array($payment_method, $gateway_names )) {
                $merge_fields['abortsend'] = true; // don't send email
                if ($logfile) {
                    $pid = getmypid();
                    $logline = sprintf(
                        "%s pre_send_email[%d]: ".
                        "Not sending email '%s' to client %s (%s) for invoice %s because the payment method is %s\n",
                        date("Y-m-d H:i:s"),
                        $pid,
                        $vars['messagename'],
                        $client_name,
			                  $client_id,
			                  $invoice_id,
			                  $payment_method,
                    );

                    $fh = fopen($logfile, "a");
                    fwrite($fh, $logline);
                    fclose($fh);
                }
            }
        }
    }

    return $merge_fields;
}

add_hook("EmailPreSend", 10, "hook_disable_invoice_notification");