The Java EE 5 Tutorial

The orderForm Page

orderForm displays the current contents of the shopping cart. The first time the page is requested, the quantities of all the coffees are 0 (zero). Each time the customer changes the coffee amounts and clicks the Update button, the request is posted back to orderForm.

The CoffeeBreakBean bean component updates the values in the shopping cart, which are then redisplayed by orderForm. When the order is complete, the customer proceeds to the checkoutForm page by clicking the Checkout button.

The table of coffees displayed on the orderForm is rendered using one of the JavaServer Faces component tags, dataTable. Here is part of the dataTable tag from orderForm:

<h:dataTable id="table"
        list-column-center, list-column-right"
    headerClass="list-header" rowClasses="list-row"
    value="#{CoffeeBreakBean.cart.items}" var="sci">
    <f:facet name="header">
        <h:outputText  value="#{CBMessages.OrderForm}"/>
        <f:facet name="header">
            <h:outputText  value="Coffee"/>
        <h:outputText id="coffeeName"

When this tag is processed, a UIData component and a Table renderer are created on the server side. The UIData component supports a data binding to a collection of data objects. The Table renderer takes care of generating the HTML markup. The UIData component iterates through the list of coffees, and the Table renderer renders each row in the table.

This example is a classic use case for a UIData component because the number of coffees might not be known to the application developer or the page author at the time the application is developed. Also, the UIData component can dynamically adjust the number of rows in the table to accommodate the underlying data.

For more information on UIData, please see Using Data-Bound Table Components.