Magento One-Page checkout mod - magento

Question

I'm writing a new shipping method for a customer; I've got the shipping calculations going great, and they appear in the 'shipping method' step - however, I want to:
a) Force the 'Shipping Information' tab to open after the user hits the billing.save() triggered by the continue button in the first (billing) tab, even if they select ship to billing address; and
b) Add options for 'receipted delivery', 'transport assurance' and 'tail-truck pickup' in the shipping information tab - which will be taken in to account when re-calculating the shipping quote.
In part b) I assume I override the shipping.phtml template with an xml config file in /layout, and then look for those added post fields in the collectRates() method.
Thanks in advance!

Answer 1

As for part a) you will need to overwrite the controller Mage_Checkout_OnepageController. To do so create your own module (I assume you know how to do this) and in the app/code/local/YourModule/etc/config.xml you should have this part:
<config>
...
<frontend>
<routers>
<checkout>
<args>
<modules>
<YourModule_Checkout before="Mage_Checkout">YourModule_Checkout</YourModule_Checkout>
</modules>
</args>
</checkout>
</routers>
</frontend>
</config>
then in app/code/local/YourModule/controllers/OnepageController.php you want to overwrite the behavior, so when you click the save billing button, you will always land on the shipping page.
include_once("Mage/Checkout/controllers/OnepageController.php");
class YourModule_Checkout_OnepageController extends Mage_Checkout_OnepageController
{
public function saveBillingAction()
{
if ($this->_expireAjax()) {
return;
}
if ($this->getRequest()->isPost()) {
$data = $this->getRequest()->getPost('billing', array());
$customerAddressId = $this->getRequest()->getPost('billing_address_id', false);
if (isset($data['email'])) {
$data['email'] = trim($data['email']);
}
$result = $this->getOnepage()->saveBilling($data, $customerAddressId);
if (!isset($result['error'])) {
/* check quote for virtual */
if ($this->getOnepage()->getQuote()->isVirtual()) {
$result['goto_section'] = 'payment';
$result['update_section'] = array(
'name' => 'payment-method',
'html' => $this->_getPaymentMethodsHtml()
);
} else { // Removed elseif block here which usually skips over shipping if you selected to use the same address as in billing
$result['goto_section'] = 'shipping';
}
}
$this->getResponse()->setBody(Mage::helper('core')->jsonEncode($result));
}
}
}
Then for part b) you have two options. Either as you pointed out you use the XML layout system to set a different template for the shipping.phtml:
<checkout_onepage_index>
<reference name="checkout.onepage.shipping">
<action method="setTemplate">
<new>my_shipping.phtml</new>
</action>
</reference>
</checkout_onepage_index>
or even easier, you overwritte the shipping.phtml template using your custom design folder.
To evaluate your custom data, the model Mage_Checkout_Model_Type_Onepage processes the data in the saveShipping() method, so I guess this would be a good point to look for implementing your custom logic.