yii framework simple shopping cart tutorial for beginners
  Provides shpping cart functionality for models.  Cart is a container object that holds items collection and have handy methods to work with it.  It uses user session as a cart data storage.   Installing and configuring   1 way: Registration in the config file  Add to protected/config/main.php :  [php] 'import'=>array(     'ext.yiiext.components.shoppingCart.*' ),  'components' => array(   'shoppingCart' =>     array(         'class' => 'ext.yiiext.components.shoppingCart.EShoppingCart',     ), )   2 way: Registration by necessity  [php] $cart = Yii::createComponent(array(     'class' => 'ext.yiiext.components.shoppingCart.EShoppingCart' )); //Important! $cart->init();  $book = Book::model()->findByPk(1); $cart->put($book);   Preparing a model  Models that you are planning to put into the cart should implement IECartPosition  interface:  [php] class Book extends CActiveRecord implements IECartPosit...