Prestashop 1.6.1.14 - Overriding HTMLTemplate.php

[PrestashopEnthu]

I am trying to override a PDF class called HTMLTemplate.php which is displaying a .tpl file called footer.tpl. I have created a custom module and create a file as such.

module/<mymodule>/override/class/pdf/HTMLTemplate.php

Code content:

<?php
class HTMLTemplate extends HTMLTemplateCore
{
 	 /**
     * Returns the template's HTML footer
     *
     * @return string HTML footer
     */
    /*
    * module: customfooter
    * date: 2017-11-14 16:57:22
    * version: 1.0
    */
    public function getFooter()
    {
        $shop_address = $this->getShopAddress();
        $id_shop = (int)$this->shop->id;
        $this->smarty->assign(array(
            'available_in_your_account' => $this->available_in_your_account,
            'shop_address' => $shop_address,
            'shop_fax' => Configuration::get('PS_SHOP_FAX', null, null, $id_shop),
            'shop_phone' => Configuration::get('PS_SHOP_PHONE', null, null, $id_shop),
            'shop_email' => Configuration::get('PS_SHOP_EMAIL', null, null, $id_shop),
            'free_text' => Configuration::get('PS_INVOICE_FREE_TEXT', (int)Context::getContext()->language->id, null, $id_shop)
        ));
        return $this->smarty->fetch($this->getTemplate('footer'));
    }
}

I would like it to read from another .tpl file which I will replace footer.tpl. I intend to customize the footer better. It is currently giving me a 500 error when I click "View Invoice".

Can anyone advise me?

Thank you.

Edited November 14, 2017 by Enthu86 (see edit history)