Document Information


Part I Introduction

1.  Overview

2.  Using the Tutorial Examples

Part II The Web Tier

3.  Getting Started with Web Applications

4.  JavaServer Faces Technology

5.  Introduction to Facelets

6.  Expression Language

7.  Using JavaServer Faces Technology in Web Pages

8.  Using Converters, Listeners, and Validators

9.  Developing with JavaServer Faces Technology

10.  JavaServer Faces Technology: Advanced Concepts

11.  Using Ajax with JavaServer Faces Technology

Overview of Ajax

Using Ajax Functionality with JavaServer Faces Technology

Using Ajax with Facelets

Using the f:ajax Tag

Monitoring Events on the Client

Handling Errors

Receiving an Ajax Response

Ajax Request Lifecycle

Grouping of Components

Loading JavaScript as a Resource

Using JavaScript API in a Facelets Application

Using the @ResourceDependency Annotation in a Bean Class

The ajaxguessnumber Example Application

The ajaxguessnumber Source Files

The ajaxgreeting.xhtml Facelets Page

The ui.js JavaScript File

The UserNumberBean Managed Bean

Running the ajaxguessnumber Example

To Build, Package, and Deploy the ajaxguessnumber Example Using NetBeans IDE

To Build, Package, and Deploy the ajaxguessnumber Example Using Ant

To Run the ajaxguessnumber Example

Further Information about Ajax in JavaServer Faces Technology

12.  Composite Components: Advanced Topics and Example

13.  Creating Custom UI Components and Other Custom Objects

14.  Configuring JavaServer Faces Applications

15.  Java Servlet Technology

16.  Uploading Files with Java Servlet Technology

17.  Internationalizing and Localizing Web Applications

Part III Web Services

18.  Introduction to Web Services

19.  Building Web Services with JAX-WS

20.  Building RESTful Web Services with JAX-RS

21.  JAX-RS: Advanced Topics and Example

Part IV Enterprise Beans

22.  Enterprise Beans

23.  Getting Started with Enterprise Beans

24.  Running the Enterprise Bean Examples

25.  A Message-Driven Bean Example

26.  Using the Embedded Enterprise Bean Container

27.  Using Asynchronous Method Invocation in Session Beans

Part V Contexts and Dependency Injection for the Java EE Platform

28.  Introduction to Contexts and Dependency Injection for the Java EE Platform

29.  Running the Basic Contexts and Dependency Injection Examples

30.  Contexts and Dependency Injection for the Java EE Platform: Advanced Topics

31.  Running the Advanced Contexts and Dependency Injection Examples

Part VI Persistence

32.  Introduction to the Java Persistence API

33.  Running the Persistence Examples

34.  The Java Persistence Query Language

35.  Using the Criteria API to Create Queries

36.  Creating and Using String-Based Criteria Queries

37.  Controlling Concurrent Access to Entity Data with Locking

38.  Using a Second-Level Cache with Java Persistence API Applications

Part VII Security

39.  Introduction to Security in the Java EE Platform

40.  Getting Started Securing Web Applications

41.  Getting Started Securing Enterprise Applications

42.  Java EE Security: Advanced Topics

Part VIII Java EE Supporting Technologies

43.  Introduction to Java EE Supporting Technologies

44.  Transactions

45.  Resources and Resource Adapters

46.  The Resource Adapter Example

47.  Java Message Service Concepts

48.  Java Message Service Examples

49.  Bean Validation: Advanced Topics

50.  Using Java EE Interceptors

Part IX Case Studies

51.  Duke's Bookstore Case Study Example

52.  Duke's Tutoring Case Study Example

53.  Duke's Forest Case Study Example



Sending an Ajax Request

To activate Ajax functionality, the web application must create an Ajax request and send it to the server. The server then processes the request.

The application uses the attributes of the f:ajax tag listed in Table 11-1 to create the Ajax request. The following sections explain the process of creating and sending an Ajax request using some of these attributes.

Note - Behind the scenes, the jsf.ajax.request() method of the JavaScript resource library collects the data provided by the f:ajax tag and posts the request to the JavaServer Faces lifecycle.

Using the event Attribute

The event attribute defines the event that triggers the Ajax action. Some of the possible values for this attribute are click, keyup, mouseover, focus, and blur.

If not specified, a default event based on the parent component will be applied. The default event is action for javax.faces.component.ActionSource components such as a commandButton, and valueChange for javax.faces.component.EditableValueHolder components such as inputText. In the following example, an Ajax tag is associated with the button component, and the event that triggers the Ajax action is a mouse click:

<h:commandButton id="submit" value="Submit"> 
    <f:ajax event="click" />
<h:outputText id="result" value="#{userNumberBean.response}" />

Note - You may have noticed that the listed events are very similar to JavaScript events. In fact, they are based on JavaScript events, but do not have the on prefix.

For a command button, the default event is click, so that you do not actually need to specify event="click" to obtain the desired behavior.

Using the execute Attribute

The execute attribute defines the component or components to be executed on the server. The component is identified by its id attribute. You can specify more than one executable component. If more than one component is to be executed, specify a space-delimited list of components.

When a component is executed, it participates in all phases of the request processing lifecycle except the Render Response phase.

The execute attribute can also be a keyword, such as @all, @none, @this, or @form. The default value is @this, which refers to the component within which the f:ajax tag is nested.

The following code specifies that the h:inputText component with the id value of userNo should be executed when the button is clicked:

<h:inputText id="userNo" 
             title="Type a number from 0 to 10:"
<h:commandButton id="submit" value="Submit"> 
    <f:ajax event="click" execute="userNo" />

Using the immediate Attribute

The immediate attribute indicates whether user inputs are to be processed early in the application lifecycle or later. If the attribute is set to true, events generated from this component are broadcast during the Apply Request Values phase. Otherwise, the events will be broadcast during the Invoke Applications phase.

If not defined, the default value of this attribute is false.

Using the listener Attribute

The listener attribute refers to a method expression that is executed on the server side in response to an Ajax action on the client. The listener’s javax.faces.event.AjaxBehaviorListener.processAjaxBehavior method is called once during the Invoke Application phase of the lifecycle. In the following example, a listener attribute is defined by an f:ajax tag, which refers to a method from the bean.

<f:ajax listener="#{mybean.someaction}" render="somecomponent" />

The following code represents the someaction method in mybean.

public void someaction(AjaxBehaviorEvent event) {