How to get Shopping Cart Discounts in Magento?

Question

Having multiple promotions (or discounts) applied for shopping carts, how to get such promotions so I can display them in view?

Update: I want to get each. NOT the total. This is so I can display the labels of each promotions/discounts for the cart. Such as:

Sub Total: 100.00
Discounts:
   First Purchase: -10 (10%),
   Employee Discount: 5 (5%)
Shipping Fee: 20.00
Grand Total: 105

Answer 1

$appliedRuleIds = Mage::getSingleton('checkout/session')->getQuote()->getAppliedRuleIds();

This will give you the ids of the rules applied to the quote separated by comma.
you can turn them into an array like this:

$appliedRuleIds = explode(',', $appliedRuleIds);

if you want to get the rules applied as objects you can do this:

$rules =  Mage::getModel('salesrule/rule')->getCollection()->addFieldToFilter('rule_id' , array('in' => $appliedRuleIds));

foreach ($rules as $rule) {
    //do something with $rule
}