How to use custom variable in magento custom module

Question

I have created a custom module for send SMS at the time of order place, I have created a observer for this which works and send SMS to customer. I have provide message field in system configration and want to send this message to customer but I don't know how to create and use custom variable {order_id} in sms configration setting.

System configration setting figure as below : enter image description here

As shown in above figure I want to use custom variable in message input field and want to send order_id from observer when message send.

Answer 1

Use strtr It will translate parts of a string.

 $orderid = "51";
 $vars = array(
 '{$orderid}' => $orderid,
 '{{order_id}}' => $orderid,
); 
echo strtr($data, $vars);

• Vinaya Maheshwari: Thanks for reply, Are you sure this is the correct way to replace {order_id} by $order_id, Is there not any another method for define and use variables?
• Qaisar Satti: defined method for emails you are not using the email template so that is solution for you..