Magento change shipping rate in one page checkout for COD - php

Question

My question is quite simple. I need to change the shipping rate cost in one page checkout to "0" once the user select COD as payment method in one page checkout. I think I can do this easely with an observer. Could you please helpme to know what event should I observe?.
Can I use checkout_controller_onepage_save_shipping_method ?. Any kind of help will be highly appreciated!!
Details Posted By OP as answer
I override the Mage_Checkout_Model_Type_Onepage class and modify the savePayment method. Then I did this:
1.- A first try:
public function savePayment($data)
{
.....
....
$payment = $quote->getPayment();
$payment->importData($data);
$quote->save();
//My custom code
if($data['method']=='cashondelivery'){
$shipping = $quote->getShippingAddress();
$address = $quote->getBillingAddress();
$shipping->addData($address)->setShippingMethod('flatrate_flatrate');
}
Where my flatrate_flatrate is 0. Unfortunately it doesn't work well. This snippet set to 0 my Grant Total.
My second try was:
public function savePayment($data)
{
.....
....
$payment = $quote->getPayment();
$payment->importData($data);
$quote->save();
//My custom code
if($data['method']=='cashondelivery'){
$this->getQuote()->getShippingAddress()->setShippingAmount(0);
$this->getQuote()->getShippingAddress()->setBaseShippingAmount(0);
}
This code works but only a few times, I don't understand why ??.. Could somebody helpme to fix this please?. Any kind of help will be highly appreciated.
Kind regards!
Ok. Now I have this and it works but it doesn't update the grand total amount. Even the order is processed with the normal shipping cost. I mean, finally it doesn't update anything. Could somebody in someway give me a hand on this please?.
if($data['method']=='cashondelivery'){
$quote->getShippingAddress()->setShippingMethod('flatrate_flatrate');
$quote->getShippingAddress()->setShippingAmount(0);
$quote->getShippingAddress()->setBaseShippingAmount(0);
$quote->getShippingAddress()->setShippingInclTax(0);
$quote->getShippingAddress()->setBaseShippingInclTax(0);
$quote->collectTotals();
$quote->save();
}
Warming regards!
Ok, I did something crazy but it seems it works (at least partially). I override Mage_Checkout_OnepageController too and add it a new method call actualizaShippingMethodAction.
It looks like this:
public function actualizaShippingMethodAction()
{
if ($this->_expireAjax()) {
return;
}
if ($this->getRequest()->isPost()) {
$data = $this->getRequest()->getPost('shipping_method', '');
$result = $this->getOnepage()->saveShippingMethod($data);
// $result will contain error data if shipping method is empty
if (!$result) {
$this->getOnepage()->getQuote()->collectTotals();
}
$this->getOnepage()->getQuote()->collectTotals()->save();
}
}
Now in my original class that is overriding (Mage_Checkout_Model_Type_Onepage) I did this.
if($data['method']=='cashondelivery'){
$cliente = new Varien_Http_Client();
$_configuracion = array('maxredirects'=>5, 'timeout'=>30);
$llamada = Mage::getBaseUrl()."checkout/onepage/actualizaShippingMethod/";
$cliente->setUri($llamada)
->setConfig($_configuracion)
->setMethod(Zend_Http_Client::POST)
->setParameterPost('shipping_method','flatrate_flatrate');
$respuesta = $cliente->request();
$quote->getShippingAddress()->setShippingAmount(0);
$quote->getShippingAddress()->setBaseShippingAmount(0);
$quote->getShippingAddress()->setShippingInclTax(0);
$quote->getShippingAddress()->setBaseShippingInclTax(0);
$quote->collectTotals()->save();
}
$this->getCheckout()
->setStepData('payment', 'complete', true)
->setStepData('review', 'allow', true);
return array();
Now the order is passing without shipping cost as spected but the order review (summary) is not updating the final costs. And I thinks this solution has a bug because if the user returns and select another payment method the shipping cost is 0 again.
Any kind of help, whatever, will be highly, highly appreciated
THANKS

Answer 1

Finally I have a solution and I think is an answer to the original question. If not please pardon me.
Forget to override savePayment($data) on Mage_Checkout_Model_Type_Onepage. Just focus on overriding Mage_Checkout_OnepageController, and add to the savePaymentAction() method the following code.
$data = $this->getRequest()->getPost('payment', array());
/*Custom code*/
if($data['method']=='cashondelivery'){//Only if payment method is cashondelivery
$result = $this->getOnepage()->savePayment($data);
// get section and redirect data
$redirectUrl = $this->getOnepage()->getQuote()->getPayment()->getCheckoutRedirectUrl();
if (empty($result['error']) && !$redirectUrl) {
$this->loadLayout('checkout_onepage_review');
$result['goto_section'] = 'review';
$result['update_section'] = array(
'name' => 'review',
'html' => $this->_getReviewHtml()
);
}
if ($redirectUrl) {
$result['redirect'] = $redirectUrl;
}
//Update totals for Shipping Methods
$resultado = $this->getOnepage()->saveShippingMethod('flatrate_flatrate');
$this->getOnepage()->getQuote()->collectTotals()->save();
}else{
$result = $this->getOnepage()->savePayment($data);
// get section and redirect data
$redirectUrl = $this->getOnepage()->getQuote()->getPayment()->getCheckoutRedirectUrl();
if (empty($result['error']) && !$redirectUrl) {
$this->loadLayout('checkout_onepage_review');
$result['goto_section'] = 'review';
$result['update_section'] = array(
'name' => 'review',
'html' => $this->_getReviewHtml()
);
}
if ($redirectUrl) {
$result['redirect'] = $redirectUrl;
}
//Return the original values according with the initial user sellection
//I use a session variable to store the original selection
$shippingMethod = Mage::getSingleton('core/session')->getShippingInicial();
$resultado = $this->getOnepage()->saveShippingMethod($shippingMethod);
$this->getOnepage()->getQuote()->collectTotals()->save();
}
} catch (Mage_Payment_Exception $e) {
if ($e->getFields()) {
...
Then you have to override saveShippingMethodAction() and add the following code.
...
$result = $this->getOnepage()->saveShippingMethod($data);
//We store the Shipping Method initial selection
Mage::getSingleton('core/session')->setShippingInicial($data);
// $result will contain error data if shipping method is empty
if (!$result) { ...
If you test this you will find that it works as expected. But now it takes 2 loading times to correctly show the total costs in the review part. I read this question (IWD one page checkout extension Magento: review refresh) but it doesn't help a lot.
Could somebody point me in the right direction to update the review part twice?.
WARMING REGARDS!
Could somebody have an idea how to achieve this?. Regards!