The Java EE 6 Tutorial, Volume I

Data Properties

Data components must be bound to one of the backing bean property types listed in Table 9–1. The Data component is discussed in Using Data-Bound Table Components. Here is part of the start tag of dataTable from that section:

<h:dataTable  id="items"
    var="item" >

The value expression points to the items property of a shopping cart bean namedcart. The cart bean maintains a map of ShoppingCartItem beans.

The getItems method from cart bean populates a List with ShoppingCartItem instances that are saved in the items map from when the customer adds books to the cart, as shown in the following code segment:

public synchronized List getItems() {
    List results = new ArrayList();
    return results;

All the components contained in the Data component are bound to the properties of the cart bean that is bound to the entire Data component. For example, here is the h:outputText tag that displays the book title in the table:

<h:commandLink action="#{showcart.details}">
    <h:outputText value="#{item.item.title}"/>