Add product and coupon to cart together

Question

What I would like to do is add a product and a coupon to the cart at the same time from a product page.

The reasoning behind this is we are creating a landing page for a specific coupon and want to add both the product and coupon to the cart with only a single click for the user.

Answer 1

Hi Have you tried event checkout_cart_add_product_complete and This event is sending params product cart params and product object to Observer

 Mage::dispatchEvent('checkout_cart_add_product_complete',
array('product' => $product, 'request' => $this->getRequest(), 'response' => $this->getResponse())
);

That using this event you can add your coupon code

If you want apply coupon from product page then create a input on product page or product add to cart url and send (coupon_code=yourcouponCode).

then you get coupon code at observer using $oberver->getEvent()->getRequest()->getParam('coupon_code')

Mage::getSingleton('checkout/session')->getQuote()->getShippingAddress()->setCollectShippingRates(true);
Mage::getSingleton('checkout/session')->getQuote())->setCouponCode($couponCode)
->collectTotals()
->save();

Answer 2

You could customize your add to cart button to use the querystring method

See magento: URL querystring for adding product and applying discount coupon to cart

 http://www.example.com/checkout/cart/add?Product=76&qty=1&return_url=http://www.example.com/index.php/checkout/cart/couponPost?coupon_code=WQ9D-XXXX

return_url - need to be encoded

See /app/code/core/Mage/Checkout/controllers/CartController.php

/**
 * Set back redirect url to response
 *
 * @return Mage_Checkout_CartController
 */
protected function _goBack()
{
    $returnUrl = $this->getRequest()->getParam('return_url');
    if ($returnUrl) {

        if (!$this->_isUrlInternal($returnUrl)) {
            throw new Mage_Exception('External urls redirect to "' . $returnUrl . '" denied!');
        }

        $this->_getSession()->getMessages(true);
        $this->getResponse()->setRedirect($returnUrl);
    } elseif (!Mage::getStoreConfig('checkout/cart/redirect_to_cart')
        && !$this->getRequest()->getParam('in_cart')
        && $backUrl = $this->_getRefererUrl()
    ) 

Answer 3

Another approach is to look at the SalguaMagentoAddProduct extension https://github.com/salgua/SalguaMagentoAddProduct it provides the ability to do what you are looking for.