ShoppingCart steps how to create and manage it

ShoppingCart component stores a user’s current and saved shopping carts. You can use the ShoppingCart component’s properties and handle methods to create a new shopping cart or retrieve one of the user’s saved shopping carts and make it the user’s current shopping cart. Shopping cart is an Order in an INCOMPLETE state. The shopping cart stores the information about the items a given customer wants to order and their associated quantities and prices. In addition, it stores the shipping and payment information for the order.

ShoppingCart Component
The ShoppingCart component is responsible for storing and managing a customer’s shopping carts. It maintains the customer’s current shopping cart that is used during the purchase process, and it stores any other shopping carts that have been persisted by that customer. These shopping carts are represented as atg.commerce.order.Order objects in the Oracle ATG Web Commerce object model, and represented as order items in the Order Repository.

By default, the /atg/commerce/ShoppingCart component is a session-scoped instance of atg.commerce.order.OrderHolder.

 Managing Shopping Carts
    Creating and Retrieving Shopping Carts
    Adding Items to Shopping Carts
    Adding Shipping Information to Shopping Carts
    Adding Payment Information to Shopping Carts
    Repricing Shopping Carts
    Saving Shopping Carts

ShoppingCart.savedEmpty property is checked to determine whether the current user has any saved shopping carts. If the user doesn’t have any saved shopping carts, the user can be given the option to create one. If the user has saved shopping carts, the user can be given the option to select one of the saved shopping carts.

OrderLookup servlet bean used to retrieve a user’s incomplete orders (that is, shopping carts). OrderLookup enables to retrieve a single order, all orders assigned to a particular cost center , all orders placed by a particular user, or all orders placed by a particular user that are in specific state, such as INCOMPLETE. Once the desired shopping cart is moved to ShoppingCart.current, you can use a ForEach servlet bean to iterate over the commerce items in the cart and display them.

When the user clicks the Add To Cart submit button, the form is processed, the properties of CartModifierFormHandler are set, and the handleAddItemToOrder method of CartModifierFormHandler is invoked. The handleAddItemToOrder method adds the quantity (specified in CartModifierFormHandler.quantity) of the selected SKU (specified in CartModifierFormHandler.catalogRefIds and identified by repository ID) to the current Order and then re-prices the Order.

Adding Multiple Items at Once

You can create pages that allow users to add multiple items to the current shopping cart in a single form submission. The items can refer to different products, different SKUs, and have different quantities. The CartModifierFormHandler contains an items property that allows you to set per-item property values.

When the user clicks the Add To Cart submit button, the form is processed, the properties of CartModifierFormHandler are set, and the handleAddItemToOrder method of CartModifierFormHandler is invoked. The handleAddItemToOrder method iterates through the CartModifierFormHandler.items elements and adds an item for each element quantity, using that element’s productId and catalogRefId for the new item.

The CartModifierFormHandler must be told how many elements to allocate for the items array. This is done by setting the CartModifierFormHandler.addItemCount property.

Overriding the Default Commerce Item Type
By default, Oracle ATG Web Commerce supports three types of commerce items. One corresponds to regular SKUs. The other two correspond to configurable SKUs and their subproperties

The commerceItemType property of CartModifierFormHandler determines what type of commerce item is created by addItemToOrder. Normally, commerceItemType is set to “default.” You can specify a different commerce item type in the CartModifierFormHandler configuration file or in a form input field. If you add multiple items in a single form submission, you can override the CartModifierFormHandler.commerceItemType setting for an individual item by including a hidden input field to set CartModifierFormHandler.items[n].commerceItemType.

Values for commerceItemType must match keys in /atg/commerce/order/OrderTools.commerceItemTypeClassMap.

The CartModifierFormHandler.addItemToOrder method has built-in support for some types of commerce item extensions. If your sites have extended commerce items with primitive data type properties, you can supply values for those properties by associating form fields with the CartModifierFormHandler.value Dictionary.

Removing Items from the Shopping Cart
The CartModifierFormHandler.deleteItems method deletes items that have their CommerceItemIds in the RemovalCommerceIds array. The quantity of the line item that contains the removal request is compared with the total quantity of the commerce item on the page. If the quantities match, the CommerceItemIds is kept in the RemovalCatalogRefIds array to be removed from the page. If the quantities do not match, the system adjusts the quantity accordingly and removes the CommerceItemId from the RemovalCommerceIds array.

Before the deleteItems method removes all items with IDs in the removalCommerceIds array, it runs the prepareLineItemsForRemoval method to return the valid array of IDs to remove, as well as verify if the IDs require partial or complete removal. The prepareLineItemsForRemoval method populates the removalLineItem map that contains a set of IDs and reduction-quantity. The reduction-quantity is subtracted from the original quantity to provide the new quantity available in the shopping cart. Once the deleteItems method removes the necessary elements, it processes the removalLineItems map to adjust the quantities of items that were partially removed.

Adding Shipping Information to Shopping Carts
Creating a list of shipping groups for potential use in the current order. The user can select from among these shipping groups when checking out the order.

1.     Specifying the shipping groups to use with the current order.
2.     Selecting the shipping methods, such as Ground or Next Day, for the order’s shipping groups.

ShippingGroupFormHandler form handler and AvailableShippingMethods servlet bean, do not re-price a given Order. Consequently, if you enable customers to make order changes that affect order price through either mechanism, you should reprice the given Order using the RepriceOrderDroplet servlet bean before displaying its price to the customer.

If an order contains any gift items, ShippingGroupDroplet and ShippingGroupFormHandler treat those items and their shipping information differently from other items.

Creating Potential Shipping Groups

Shipping groups for potential use in an Order in one of two ways:

1.     from information gathered from the user via forms
2.     from information stored in the user’s profile

To create shipping groups from information obtained from the user via forms, use CreateHardgoodShippingGroupFormHandler and CreateElectronicShippingGroupFormHandler. These form handlers create, respectively, hard good and electronic shipping groups. Additionally, if the addToContainer property of the form handlers is set to true (which it is by default), they add the new shipping group to the ShippingGroupMapContainer and make it the default shipping group in the container. The ShippingGroupMapContainer stores the shipping groups available for use in the current order. Once the shipping group is added to the ShippingGroupMapContainer, the user can use it when checking out the current order.

Adding Payment Information to Shopping Carts

Adding payment information to shopping carts involves the following sub-processes:

1. Creating a list of payment groups for potential use in the current order. The user can select from among these payment groups when checking out the order.
2. Specifying the payment groups to use with current order.

Creating Potential Payment Groups

You can create a list of payment groups for potential use in an Order in one of two ways:

1.     from information gathered from the user via forms
2.     from information stored in the user’s profile

To create payment groups from information obtained from the user via forms, use CreateCreditCardFormHandler and CreateInvoiceRequestFormHandler. These form handlers create, respectively, CreditCard and InvoiceRequest payment groups. Additionally, if the addToContainer property of the form handlers is true (which it is by default), they add the new payment group to the PaymentGroupMapContainer and make it the default payment group in the container. The PaymentGroupMapContainer stores the payment groups available for use in the current order. Once the payment group is added to the PaymentGroupMapContainer, the user can use it when checking out the current order.

Repricing Shopping Carts

Adding Items to Shopping Carts, CartModifierFormHandler automatically reprices a shopping cart when it is used to add items to the cart. (Note that it also reprices the cart when it is used to remove items from the cart.)

However, you’ll need to reprice shopping carts via some other mechanism if customers can make changes that affect order price through other form handlers that do not reprice shopping carts (for example, by making shipping changes via the form handlers that create and manage shipping groups), or if the shopping carts are modified through some other means in ways that affect order price, such as the delivery of a promotion via a scenario.

Any pages where you need to reprice a shopping cart, but you cannot do so through a form action and corresponding handle method, use the RepriceOrderDroplet servlet bean. In fact, you can use the RepriceOrderDroplet servlet bean to reprice a customer’s shopping cart every time the customer accesses a shopping cart page. This ensures that the customer always views accurate pricing information as he or she makes changes to cart.

The RepriceOrderDroplet servlet bean takes one required input parameter, pricingOp, that should be set to the pricing operation to execute. The possible pricing operations are defined in atg.commerce.pricing.PricingConstants, and they include the following:

    ORDER_TOTAL
    ORDER_SUBTOTAL
    ORDER_SUBTOTAL_SHIPPING
    ORDER_SUBTOTAL_TAX
    ITEMS
    SHIPPING
    ORDER
    TAX
    NO_REPRICE

Typically, the pricingOp input parameter is the only parameter you need to specify when using RepriceOrderDroplet.

<dsp:droplet name="RepriceOrderDroplet">
  <dsp:param value="ORDER_SUBTOTAL" name="pricingOp"/>
</dsp:droplet>

Saving Shopping Carts

SaveOrderFormHandler to save the user’s current shopping cart, add the shopping cart to the user’s list of saved carts in ShoppingCart.saved, and construct a new, empty cart as the user’s current shopping cart in ShoppingCart.current.

Additionally, you can use the description property of SaveOrderFormHandler to set the description property of the Order; this enables users to name their shopping carts with meaningful names. If the user doesn’t provide a descriptive name, then the SaveOrderFormHandler automatically creates one using the user’s locale and the current date and time.

The following JSP code illustrates the use of SaveOrderFormHandler.

<dsp:importbean bean="/atg/commerce/order/purchase/SaveOrderFormHandler"/>

Order # <dsp:valueof bean="ShoppingCart.current.id"/>
  <dsp:form action="saved_orders.jsp">
    Enter a name to identify this order:<p>
    <dsp:input bean="SaveOrderFormHandler.description" type="text"/>
    <dsp:input bean="SaveOrderFormHandler.saveOrder" value="Save order"
         type="submit"/>
    <dsp:input bean="SaveOrderFormHandler.saveOrderSuccessURL"
         value="../user/saved_orders.jsp" type="hidden"/>
    <dsp:input bean="SaveOrderFormHandler.saveOrderErrorURL"
         value="../user/save_order.jsp" type="hidden"/>
  </dsp:form>