Modifying the order summary table in the review step of onepage checkout?

Question

I'm using the default onepage checkout in Magento 1.9. My application has a customized checkout UI which requires me to "shrink" the order summary table. Where it the file for this table stored? Unfortunately, CSS won't do the trick because I need to remove 2 columns and adjust the colspan of the rows in the footer. Tracing billing.save() after saving the billing form, I followed the code to Mage/Checkout/controllers/OnepageController.php which contains:

 protected function _getReviewHtml()
    {
        return $this->getLayout()->getBlock('root')->toHtml();
    }

But I don't understand how _getReviewHtml() gets the review order summary by grabbing the root block. Can somebody please explain how this results in the html for the order summary table in the review step of onepage checkout and how can I modify the structure of the table?

Answer 1

Main reason is function savePaymentAction().

Whenever,this function is called that time magento

is load layout handler checkout_onepage_review on basic of when you choosed payment method does not have redirection url .

Like Cash on Delivery,Check memo,credit card save etc

if (empty($result['error']) && !$redirectUrl) {
/* call review step */
                $this->loadLayout('checkout_onepage_review');
                $result['goto_section'] = 'review';
                $result['update_section'] = array(
                    'name' => 'review',
                    'html' => $this->_getReviewHtml()
                );
            }