Which event to observe for building Magento Extension for fraud detection ?

Question

Magento Version 1.9.x

• Requirement

I need to build an extension to alter the checkout flow. I want to send the user info ( email, name, shipping address ) , order info ( product name, quantity ) plus the payment details ( card holder name, card number , payment method etc ) to my fraud detection algorithm. The extension should execute when user clicks the final PAY button. It will gather the required information ( user, order and payment details ) and send it to fraud detection algorithm server. The payment should proceed only if the response from the server is a "GO" else it will throw error message.

• Done So Far

I have made an event observer for sales_order_save_before to do so.

class Mahadev_FraudDetection_Model_Observer { public function gatherData($observer) { // $payment_info from $_POST global variable at this point. $data = $observer->getEvent()->getOrder(); Mage::log($data->debug(), null, "gatherData.log", true); } }

I can gather the payment information from $_POST variable.

• Questions

1) sales_order_save_before is the right event to use ? I need to check the order and payment details before the actual payment. If not , which event I should observe ? May be sales_order_save_before is getting triggered after the payment ( not sure yet ).

2) Will this method works with all the payment gateways? and with all kind of checkouts and payment.

3) Please suggest if I can do this in some better way. Is there any event which can give me payments information also. I do not want to gather payments information from $_POST.

4) Can you put some good link to understand advance magento development. I can't find any good resource for building these kind of extensions.

P.S. I am very new to Magento, so please feel free to correct me if I am wrong somewhere.

Thank you.

Answer 1

You should try following event

sales_order_payment_place_start

So register event in global scope like:

<events>
 <sales_order_payment_place_start>
 <observers>
 <vendor_module_sales_order_payment_place_start>
 <class>vendor_module/observer</class>
 <method>fraudDetection</method>
 </vendor_module_sales_order_payment_place_start>
 </observers>
 </sales_order_payment_place_start>
</events>

app/code/local/Vendor/Module/Model/Observer.php

class Vendor_Module_Model_Observer
{
 public function fraudDetection($observer)
 {
 $payment = $observer->getEvent()->getPayment();
 Mage::log($payment->getCcNumber());
 Mage::throwException(
 Mage::helper('sales')->__('The transaction cannot be fulfil.')
 );
 return;
 }
}

• Ryan Hoerr: This answer is good. Note that it WILL NOT work for all payment methods--all payment methods should fire the observer, but not all have the full credit card number available. Any methods that redirect (PayPal Express) or do a direct post or JS post (Authorize.Net Direct Post, and many others) will at most give you the CC type, expiration date, and last 4 digits.