Add Custom Invoice Data in Invoice email

Question

This is my email template file for invoice email:

\wamp\www\magento\app\locale\en_US\template\email\sales\invoice_new.html

<td>
<h2 style="font-size:18px; font-weight:normal; margin:0;">Your Invoice #{{var invoice.increment_id}} for Order #{{var
order.increment_id}}</h2>
</td>

I don't understand how to pass the order id to this html file.

{{var invoice.increment_id}} from where this varible pass in this html file??
{{var order.getShippingAddress().getTelephone()}} where is written this function in magento ?

I want to use this variable and create function to get more data from magento table. So for that where do I have to add this function and how to call this function in invoice_new.html file?

Answer 1

The variables are set in Mage_Sales_Model_Order_Invoice::sendEmail(). See this code:

    $mailer->setTemplateParams(array(
            'order'        => $order,
            'invoice'      => $this,
            'comment'      => $comment,
            'billing'      => $order->getBillingAddress(),
            'payment_html' => $paymentBlockHtml
        )
    );

You can add your own data the same way.