Configuring Jakarta Faces Applications

This chapter describes additional configuration tasks required when you create large and complex applications.

Introduction to Configuring Jakarta Faces Applications

The process of building and deploying simple Jakarta Faces applications is described in earlier chapters of this tutorial, including Getting Started with Web Applications, Introduction to Facelets, Using Ajax with Jakarta Faces Technology and Composite Components: Advanced Topics and an Example When you create large and complex applications, however, various additional configuration tasks are required. These tasks include the following:

Registering managed beans with the application so that all parts of the application have access to them
Configuring managed beans and model beans so that they are instantiated with the proper values when a page makes reference to them
Defining navigation rules for each of the pages in the application so that the application has a smooth page flow, if nondefault navigation is needed
Packaging the application to include all the pages, resources, and other files so that the application can be deployed on any compliant container

Using Annotations to Configure Managed Beans

In Jakarta Faces 2.3, managed bean annotations are deprecated; CDI is now the preferred approach.

Jakarta Faces support for bean annotations is introduced in Jakarta Faces Technology. Bean annotations can be used for configuring Jakarta Faces applications.

The @Named (jakarta.inject.Named) annotation in a class, along with a scope annotation, automatically registers that class as a resource with the Jakarta Faces implementation. A bean that uses these annotations is a CDI managed bean.

The following shows the use of the @Named and @SessionScoped annotations in a class:

@Named("cart")
@SessionScoped
public class ShoppingCart ... { ... }

The above code snippet shows a bean that is managed by the Jakarta Faces implementation and is available for the length of the session.

You can annotate beans with any of the scopes listed in the next section, Using Managed Bean Scopes.

All classes will be scanned for annotations at startup unless the faces-config element in the faces-config.xml file has the metadata-complete attribute set to true.

Annotations are also available for other artifacts, such as components, converters, validators, and renderers, to be used in place of application configuration resource file entries. These are discussed, along with registration of custom listeners, custom validators, and custom converters, in Creating Custom UI Components and Other Custom Objects.

Using Managed Bean Scopes

You can use annotations to define the scope in which the bean will be stored. You can specify one of the following scopes for a bean class.

Application (jakarta.enterprise.context.ApplicationScoped): Application scope persists across all users' interactions with a web application.
Session (jakarta.enterprise.context.SessionScoped): Session scope persists across multiple HTTP requests in a web application.
Flow (jakarta.faces.flows.FlowScoped): Flow scope persists during a user’s interaction with a specific flow of a web application. See Using Faces Flows for more information.
Request (jakarta.enterprise.context.RequestScoped): Request scope persists during a single HTTP request in a web application.
Dependent (jakarta.enterprise.context.Dependent): Indicates that the bean depends on some other bean.

You may want to use @Dependent when a managed bean references another managed bean. The second bean should not be in a scope (@Dependent) if it is supposed to be created only when it is referenced. If you define a bean as @Dependent, the bean is instantiated anew each time it is referenced, so it does not get saved in any scope.

If your managed bean is referenced by the binding attribute of a component tag, you should define the bean with a request scope. If you placed the bean in session or application scope instead, the bean would need to take precautions to ensure thread safety, because jakarta.faces.component.UIComponent instances each depend on running inside of a single thread.

If you are configuring a bean that allows attributes to be associated with the view, you can use the view scope. The attributes persist until the user has navigated to the next view.

Application Configuration Resource File

Jakarta Faces technology provides a portable configuration format (as an XML document) for configuring application resources. One or more XML documents, called application configuration resource files, may use this format to register and configure objects and resources and to define navigation rules for applications. An application configuration resource file is usually named faces-config.xml.

You need an application configuration resource file in the following cases:

To specify configuration elements for your application that are not available through managed bean annotations, such as localized messages and navigation rules
To override managed bean annotations when the application is deployed

The application configuration resource file must be valid against the XML schema located at https://jakarta.ee/xml/ns/jakartaee/web-facesconfig_3_0.xsd.

In addition, each file must include the following information, in the following order:

The XML version number, usually with an encoding attribute:
```
<?xml version="1.0" encoding='UTF-8'?>
```

A faces-config tag enclosing all the other declarations:

<faces-config version="3.0" xmlns="https://jakarta.ee/xml/ns/jakartaee"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee
              https://jakarta.ee/xml/ns/jakartaee/web-facesconfig_3_0.xsd">
    ...
</faces-config>

You can have more than one application configuration resource file for an application. The Jakarta Faces implementation finds the configuration file or files by looking for the following.

A resource named /META-INF/faces-config.xml in any of the JAR files in the web application’s /WEB-INF/lib/ directory and in parent class loaders. If a resource with this name exists, it is loaded as a configuration resource. This method is practical for a packaged library containing some components and renderers. In addition, any file with a name that ends in faces-config.xml is also considered a configuration resource and is loaded as such.
A context initialization parameter, jakarta.faces.application.CONFIG_FILES, in your web deployment descriptor file that specifies one or more (comma-delimited) paths to multiple configuration files for your web application. This method is most often used for enterprise-scale applications that delegate to separate groups the responsibility for maintaining the file for each portion of a big application.
A resource named faces-config.xml in the /WEB-INF/ directory of your application. Simple web applications make their configuration files available in this way.

To access the resources registered with the application, an application developer can use an instance of the jakarta.faces.application.Application class, which is automatically created for each application. The Application instance acts as a centralized factory for resources that are defined in the XML file.

When an application starts up, the Jakarta Faces implementation creates a single instance of the Application class and configures it with the information you provided in the application configuration resource file.

Configuring Eager Application-Scoped Managed Beans

Jakarta Faces managed beans (either specified in the faces-config.xml file or annotated with jakarta.faces.bean.ManagedBean) are lazily instantiated. That is, that they are instantiated when a request is made from the application.

To force an application-scoped bean to be instantiated and placed in the application scope as soon as the application is started and before any request is made, the eager attribute of the managed bean should be set to true, as shown in the following examples.

The faces-config.xml file declaration is as follows:

<managed-bean eager="true">

The annotation is as follows:

@ManagedBean(eager=true)
@ApplicationScoped

Ordering of Application Configuration Resource Files

Because Jakarta Faces technology allows the use of multiple application configuration resource files stored in different locations, the order in which they are loaded by the implementation becomes important in certain situations (for example, when using application-level objects). This order can be defined through an ordering element and its subelements in the application configuration resource file itself. The ordering of application configuration resource files can be absolute or relative.

Absolute ordering is defined by an absolute-ordering element in the file. With absolute ordering, the user specifies the order in which application configuration resource files will be loaded. The following example shows an entry for absolute ordering.

File my-faces-config.xml contains the following elements:

<faces-config>
    <name>myJSF</name>
    <absolute-ordering>
        <name>A</name>
        <name>B</name>
        <name>C</name>
    </absolute-ordering>
</faces-config>

In this example, A, B, and C are different application configuration resource files and are to be loaded in the listed order.

If there is an absolute-ordering element in the file, only the files listed by the subelement name are processed. To process any other application configuration resource files, an others subelement is required. In the absence of the others subelement, all other unlisted files will be ignored at load time.

Relative ordering is defined by an ordering element and its subelements before and after. With relative ordering, the order in which application configuration resource files will be loaded is calculated by considering ordering entries from the different files. The following example shows some of these considerations. In the following example, config-A, config-B, and config-C are different application configuration resource files.

File config-A contains the following elements:

<faces-config>
    <name>config-A</name>
    <ordering>
        <before>
            <name>config-B</name>
        </before>
    </ordering>
</faces-config>

File config-B (not shown here) does not contain any ordering elements.

File config-C contains the following elements:

<faces-config>
    <name>config-C</name>
    <ordering>
        <after>
            <name>config-B</name>
        </after>
    </ordering>
</faces-config>

Based on the before subelement entry, file config-A will be loaded before the config-B file. Based on the after subelement entry, file config-C will be loaded after the config-B file.

In addition, a subelement others can also be nested within the before and after subelements. If the others element is present, the specified file may receive highest or lowest preference among both listed and unlisted configuration files.

If an ordering element is not present in an application configuration file, then that file will be loaded after all the files that contain ordering elements.

Using Faces Flows

The Faces Flows feature of Jakarta Faces technology allows you to create a set of pages with a scope, FlowScoped, that is greater than request scope but less than session scope. For example, you might want to create a series of pages for the checkout process in an online store. You could create a set of self-contained pages that could be transferred from one store to another as needed.

Faces Flows are somewhat analogous to subroutines in procedural programming, in the following ways.

Like a subroutine, a flow has a well defined entry point, list of parameters, and return value. However, unlike a subroutine, a flow can return multiple values.
Like a subroutine, a flow has a scope, allowing information to be available only during the invocation of the flow. Such information is not available outside the scope of the flow and does not consume any resources once the flow returns.
Like a subroutine, a flow may call other flows before returning. The invocation of flows is maintained in a call stack: a new flow causes a push onto the stack, and a return causes a pop.

An application can have any number of flows. Each flow includes a set of pages and, usually, one or more managed beans scoped to that flow. Each flow has a starting point, called a start node, and an exit point, called a return node.

The data in a flow is scoped to that flow alone, but you can pass data from one flow to another by specifying parameters and calling the other flow.

Flows can be nested, so that if you call one flow from another and then exit the second flow, you return to the calling flow rather than to the second flow’s return node.

You can configure a flow programmatically, by creating a class annotated @FlowDefinition, or you can configure a flow by using a configuration file. The configuration file can be limited to one flow, or you can use the faces-config.xml file to put all the flows in one place, if you have many flows in an application. The programmatic configuration places the code closer to the rest of the flow code and enables you to modularize the flows.

Figure 1, “Two Faces Flows and Their Interactions” shows two flows and illustrates how they interact.

This figure shows two Faces flows, Flow A and Flow B. Each has a start node and two additional pages. Each has an associated managed bean. Each defines a return node, and each defines two parameters to be passed to the other flow.

Figure 1. Two Faces Flows and Their Interactions

In this figure, Flow A has a start node named flow-a and two additional pages, next_a1 and next_a2. From next_a2, a user can either exit the flow using the defined return node, taskFlowReturn1, or call Flow B, passing two parameters. Flow A also defines two inbound parameters that it can accept from Flow B. Flow B is identical to Flow A except for the names of the flow and files. Each flow also has an associated managed bean; the beans are Flow_a_Bean and Flow_b_Bean.

Packaging Flows in an Application

Typically, you package flows in a web application using a directory structure that modularizes the flows. In the src/main/webapp directory of a Maven project, for example, you would place the Facelets files that are outside the flow at the top level as usual. Then the webapp files for each flow would be in a separate directory, and the Java files would be under src/main/java. For example, the files for the application shown in Figure 1, “Two Faces Flows and Their Interactions” might look like this:

src/main/webapp/
    index.xhtml
    return.xhtml
    WEB_INF/
        beans.xml
        web.xml
    flow-a/
        flow-a.xhtml
        next_a1.xhtml
        next_a2.xhtml
    flow-b/
        flow-b-flow.xml
        next_b1.xhtml
        next_b2.xhtml
src/main/java/jakarta/tutorial/flowexample
            FlowA.java
            Flow_a_Bean.java
            Flow_b_Bean.java

In this example, flow-a is defined programmatically in FlowA.java, while flow-b is defined by the configuration file flow-b-flow.xml.

The Simplest Possible Flow: The simple-flow Example Application

The simple-flow example application demonstrates the most basic building blocks of a Faces Flows application and illustrates some of the conventions that make it easy to get started with iterative development using flows. You may want to start with a simple example like this one and build upon it.

This example provides an implicit flow definition by including an empty configuration file. A configuration file that has content, or a class annotated @FlowDefinition, provides an explicit flow definition.

The source code for this application is in the jakartaee-examples/tutorial/web/faces/simple-flow/ directory.

The file layout of the simple-flow example looks like this:

src/main/webapp
    index.xhtml
    simple-flow-return.xhtml
    WEB_INF/
        web.xml
    simple-flow
        simple-flow-flow.xml
        simple-flow.xhtml
        simple-flow-page2.xhtml

The simple-flow example has an empty configuration file, which is by convention named flow-name-flow.xml. The flow does not require any configuration for the following reasons.

The flow does not call another flow, nor does it pass parameters to another flow.
The flow uses default names for the first page of the flow, flow-name.xhtml, and the return page, flow-name-return.xhtml.

This example has only four Facelets pages.

index.xhtml, the start page, which contains almost nothing but a button that navigates to the first page of the flow:
```
<h:commandButton value="Enter Flow" action="simple-flow"/>
```
simple-flow.xhtml and simple-flow-page2.xhtml, the two pages of the flow itself. In the absence of an explicit flow definition, the page whose name is the same as the name of the flow is assumed to be the start node of the flow. In this case, the flow is named simple-flow, so the page named simple-flow.xhtml is assumed to be the start node of the flow. The start node is the node navigated to upon entry into the flow. It can be thought of as the home page of the flow.

The simple-flow.xhtml page asks you to enter a flow-scoped value and provides a button that navigates to the next page of the flow:
```
Value: <h:inputText id="input" value="#{flowScope.value}" />

<h:commandButton value="Next" action="simple-flow-page2" />
```
The second page, which can have any name, displays the flow-scoped value and provides a button that navigates to the return page:
```
Value: #{flowScope.value}

<h:commandButton value="Return" action="simple-flow-return" />
```
simple-flow-return.xhtml, the return page. The return page, which by convention is named flow-name-return.xhtml, must be located outside of the flow. This page displays the flow-scoped value, to show that it has no value outside of the flow, and provides a link that navigates to the index.xhtml page:
```
Value (should be empty):
 "<h:outputText id="output" value="#{flowScope.value}" />"

<h:link outcome="index" value="Back to Start" />
```

The Facelets pages use only flow-scoped data, so the example does not need a managed bean.

To Build, Package, and Deploy the simple-flow Example Using NetBeans IDE

Make sure that GlassFish Server has been started (see Starting and Stopping GlassFish Server).
From the File menu, choose Open Project.
In the Open Project dialog box, navigate to:
```
jakartaee-examples/tutorial/web/faces
```
Select the simple-flow folder.
Click Open Project.
In the Projects tab, right-click the simple-flow project and select Build.

This command builds and packages the application into a WAR file, simple-flow.war, that is located in the target directory. It then deploys the application to the server.

To Build, Package, and Deploy the simple-flow Example Using Maven

Make sure that GlassFish Server has been started (see Starting and Stopping GlassFish Server).

In a terminal window, go to:

jakartaee-examples/tutorial/web/faces/simple-flow/

Enter the following command:
```
mvn install
```
This command builds and packages the application into a WAR file, simple-flow.war, that is located in the target directory. It then deploys the application to the server.

To Run the simple-flow Example

Enter the following URL in your web browser:
```
http://localhost:8080/simple-flow
```
On the index.xhtml page, click Enter Flow.
On the first page of the flow, enter any string in the Value field, then click Next.
On the second page of the flow, you can see the value you entered. Click Return.
On the return page, an empty pair of quotation marks encloses the inaccessible value. Click Back to Start to return to the index.xhtml page.

The checkout-module Example Application

The checkout-module example application is considerably more complex than simple-flow. It shows how you might use the Faces Flows feature to implement a checkout module for an online store.

Like the hypothetical example in Figure 1, “Two Faces Flows and Their Interactions”, the example application contains two flows, each of which can call the other. Both flows have explicit flow definitions. One flow, checkoutFlow, is specified programmatically. The other flow, joinFlow, is specified in a configuration file.

The source code for this application is in the jakartaee-examples/tutorial/web/faces/checkout-module/ directory.

For the checkout-module application, the directory structure is as follows (there is also a src/main/webapp/resources directory with a stylesheet and an image):

src/main/webapp/
    index.xhtml
    exithome.xhtml
    WEB_INF/
        beans.xml
        web.xml
    checkoutFlow/
        checkoutFlow.xhtml
        checkoutFlow2.xhtml
        checkoutFlow3.xhtml
        checkoutFlow4.xhtml
    joinFlow/
        joinFlow-flow.xml
        joinFlow.xhtml
        joinFlow2.xhtml
src/main/java/jakarta/tutorial/checkoutmodule
    CheckoutBean.java
    CheckoutFlow.java
    CheckoutFlowBean.java
    JoinFlowBean.java

For the example, index.xhtml is the beginning page for the application as well as the return node for the checkout flow. The exithome.xhtml page is the return node for the join flow.

The configuration file joinFlow-flow.xml defines the join flow, and the source file CheckoutFlow.java defines the checkout flow.

The checkout flow contains four Facelets pages, whereas the join flow contains two.

The managed beans scoped to each flow are CheckoutFlowBean.java and JoinFlowBean.java, whereas CheckoutBean.java is the backing bean for the index.html page.

The Facelets Pages for the checkout-module Example

The starting page for the example, index.xhtml, summarizes the contents of a hypothetical shopping cart. It allows the user to click either of two buttons to enter one of the two flows:

<p><h:commandButton value="Check Out" action="checkoutFlow"/></p>
...
<p><h:commandButton value="Join" action="joinFlow"/></p>

This page is also the return node for the checkout flow.

The Facelets page exithome.xhtml is the return node for the join flow. This page has a button that allows you to return to the index.xhtml page.

The four Facelets pages within the checkout flow, starting with checkoutFlow.xhtml and ending with checkoutFlow4.xhtml, allow you to proceed to the next page or, in some cases, to return from the flow. The checkoutFlow.xhtml page allows you to access parameters passed from the join flow through the flow scope. These appear as empty quotation marks if you have not called the checkout flow from the join flow.

<p>If you called this flow from the Join flow, you can see these parameters:
    "<h:outputText value="#{flowScope.param1Value}"/>" and
    "<h:outputText value="#{flowScope.param2Value}"/>"
</p>

Only checkoutFlow2.xhtml has a button to return to the previous page, but moving between pages is generally permitted within flows. Here are the buttons for checkoutFlow2.xhtml:

<p><h:commandButton value="Continue" action="checkoutFlow3"/></p>
<p><h:commandButton value="Go Back" action="checkoutFlow"/></p>
<p><h:commandButton value="Exit Flow" action="returnFromCheckoutFlow"/></p>

The action returnFromCheckoutFlow is defined in the configuration source code file, CheckoutFlow.java.

The final page of the checkout flow, checkoutFlow4.xhtml, contains a button that calls the join flow:

<p><h:commandButton value="Join" action="calljoin"/></p>
<p><h:commandButton value="Exit Flow" action="returnFromCheckoutFlow"/></p>

The calljoin action is also defined in the configuration source code file, CheckoutFlow.java. This action enters the join flow, passing two parameters from the checkout flow.

The two pages in the join flow, joinFlow.xhtml and joinFlow2.xhtml, are similar to those in the checkout flow. The second page has a button to call the checkout flow as well as one to return from the join flow:

<p><h:commandButton value="Check Out" action="callcheckoutFlow"/></p>
<p><h:commandButton value="Exit Flow" action="returnFromJoinFlow"/></p>

For this flow, the actions callcheckoutFlow and returnFromJoinFlow are defined in the configuration file joinFlow-flow.xml.

Using a Configuration File to Configure a Flow

If you use an application configuration resource file to configure a flow, it must be named flowName-flow.xml. In this example, the join flow uses a configuration file named joinFlow-flow.xml. The file is a faces-config file that specifies a flow-definition element. This element must define the flow name using the id attribute. Under the flow-definition element, there must be a flow-return element that specifies the return point for the flow. Any inbound parameters are specified with inbound-parameter elements. If the flow calls another flow, the call-flow element must use the flow-reference element to name the called flow and may use the outbound-parameter element to specify any outbound parameters.

The configuration file for the join flow looks like this:

<faces-config version="3.0" xmlns="https://jakarta.ee/xml/ns/jakartaee"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee
              https://jakarta.ee/xml/ns/jakartaee/web-facesconfig_3_0.xsd">

    <flow-definition id="joinFlow">
        <flow-return id="returnFromJoinFlow">
            <from-outcome>#{joinFlowBean.returnValue}</from-outcome>
        </flow-return>

        <flow-call id="callcheckoutFlow">
            <flow-reference>
                <flow-id>checkoutFlow</flow-id>
            </flow-reference>
            <outbound-parameter>
                <name>param1FromJoinFlow</name>
                <value>#{"param1 joinFlow value"}</value>
            </outbound-parameter>
            <outbound-parameter>
                <name>param2FromJoinFlow</name>
                <value>#{"param2 joinFlow value"}</value>
            </outbound-parameter>
        </flow-call>
        <inbound-parameter>
            <name>param1FromCheckoutFlow</name>
            <value>#{flowScope.param1Value}</value>
        </inbound-parameter>
        <inbound-parameter>
            <name>param2FromCheckoutFlow</name>
            <value>#{flowScope.param2Value}</value>
        </inbound-parameter>
    </flow-definition>
</faces-config>

The id attribute of the flow-definition element defines the name of the flow as joinFlow. The value of the id attribute of the flow-return element identifies the name of the return node, and its value is defined in the from-outcome element as the returnValue property of the flow-scoped managed bean for the join flow, JoinFlowBean.

The names and values of the inbound parameters are retrieved from the flow scope in order (flowScope.param1Value, flowScope.param2Value), based on the way they were defined in the checkout flow configuration.

The flow-call element defines how the join flow calls the checkout flow. The id attribute of the element, callcheckoutFlow, defines the action of calling the flow. Within the flow-call element, the flow-reference element defines the actual name of the flow to call, checkoutFlow. The outbound-parameter elements define the parameters to be passed when checkoutFlow is called. Here they are just arbitrary strings.

Using a Java Class to Configure a Flow

If you use a Java class to configure a flow, it must have the name of the flow. The class for the checkout flow is called CheckoutFlow.java.

import java.io.Serializable;
import jakarta.enterprise.inject.Produces;
import jakarta.faces.flow.Flow;
import jakarta.faces.flow.builder.FlowBuilder;
import jakarta.faces.flow.builder.FlowBuilderParameter;
import jakarta.faces.flow.builder.FlowDefinition;

class CheckoutFlow implements Serializable {

    private static final long serialVersionUID = 1L;

    @Produces
    @FlowDefinition
    public Flow defineFlow(@FlowBuilderParameter FlowBuilder flowBuilder) {

        String flowId = "checkoutFlow";
        flowBuilder.id("", flowId);
        flowBuilder.viewNode(flowId,
                "/" + flowId + "/" + flowId + ".xhtml").
                markAsStartNode();

        flowBuilder.returnNode("returnFromCheckoutFlow").
                fromOutcome("#{checkoutFlowBean.returnValue}");

        flowBuilder.inboundParameter("param1FromJoinFlow",
                "#{flowScope.param1Value}");
        flowBuilder.inboundParameter("param2FromJoinFlow",
                "#{flowScope.param2Value}");

        flowBuilder.flowCallNode("calljoin").flowReference("", "joinFlow").
                outboundParameter("param1FromCheckoutFlow",
                    "#{checkoutFlowBean.name}").
                outboundParameter("param2FromCheckoutFlow",
                    "#{checkoutFlowBean.city}");
        return flowBuilder.getFlow();
    }
}

The class performs actions that are almost identical to those performed by the configuration file joinFlow-flow.xml. It contains a single method, defineFlow, as a producer method with the @FlowDefinition qualifier that returns a jakarta.faces.flow.Flow class. The defineFlow method takes one parameter, a FlowBuilder with the qualifier @FlowBuilderParameter, which is passed in from the Jakarta Faces implementation. The method then calls methods from the jakarta.faces.flow.Builder.FlowBuilder class to configure the flow.

First, the method defines the flow id as checkoutFlow. Then, it explicitly defines the start node for the flow. By default, this is the name of the flow with an .xhtml suffix.

The method then defines the return node similarly to the way the configuration file does. The returnNode method sets the name of the return node as returnFromCheckoutFlow, and the chained fromOutcome method specifies its value as the returnValue property of the flow-scoped managed bean for the checkout flow, CheckoutFlowBean.

The inboundParameter method sets the names and values of the inbound parameters from the join flow, which are retrieved from the flow scope in order (flowScope.param1Value, flowScope.param2Value), based on the way they were defined in the join flow configuration.

The flowCallNode method defines how the checkout flow calls the join flow. The argument, calljoin, specifies the action of calling the flow. The chained flowReference method defines the actual name of the flow to call, joinFlow, then calls outboundParameter methods to define the parameters to be passed when joinFlow is called. Here they are values from the CheckoutFlowBean managed bean.

Finally, the defineFlow method calls the getFlow method and returns the result.

The Flow-Scoped Managed Beans

Each of the two flows has a managed bean that defines properties for the pages within the flow. For example, the CheckoutFlowBean defines properties whose values are entered by the user on both the checkoutFlow.xhtml page and the checkoutFlow3.xhtml page.

Each managed bean has a getReturnValue method that sets the value of the return node. For the CheckoutFlowBean, the return node is the index.xhtml page, specified using implicit navigation:

public String getReturnValue() {
    return "index";
}

For the JoinFlowBean, the return node is the exithome.xhtml page.

To Build, Package, and Deploy the checkout-module Example Using NetBeans IDE

Make sure that GlassFish Server has been started (see Starting and Stopping GlassFish Server).
From the File menu, choose Open Project.
In the Open Project dialog box, navigate to:
```
jakartaee-examples/tutorial/web/faces
```
Select the checkout-module folder.
Click Open Project.
In the Projects tab, right-click the checkout-module project and select Build.

This command builds and packages the application into a WAR file, checkout-module.war, that is located in the target directory. It then deploys the application to the server.

To Build, Package, and Deploy the checkout-module Example Using Maven

Make sure that GlassFish Server has been started (see Starting and Stopping GlassFish Server).

In a terminal window, go to:

jakartaee-examples/tutorial/web/faces/checkout-module/

Enter the following command:
```
mvn install
```
This command builds and packages the application into a WAR file, checkout-module.war, that is located in the target directory. It then deploys the application to the server.

To Run the checkout-module Example

Enter the following URL in your web browser:
```
http://localhost:8080/checkout-module
```
The index.xhtml page presents hypothetical results of the shopping expedition. Click either Check Out or Join to enter one of the two flows.
Follow the flow, providing input as needed and choosing whether to continue, go back, or exit the flow.

In the checkout flow, only one of the input fields is validated (the credit card field expects 16 digits), so you can enter any values you like. The join flow does not require you to check any boxes in its checkbox menus.
On the last page of a flow, select the option to enter the other flow. This allows you to view the inbound parameters from the previous flow.
Because flows are nested, if you click Exit Flow from a called flow, you will return to the first page of the calling flow (You may see a warning, which you can ignore). Click Exit Flow on that page to go to the specified return node.

Configuring Managed Beans

When a page references a managed bean for the first time, the Jakarta Faces implementation initializes it either based on a @Named annotation and scope annotation in the bean class or according to its configuration in the application configuration resource file. For information on using annotations to initialize beans, see Using Annotations to Configure Managed Beans.

You can use either annotations or the application configuration resource file to instantiate managed beans that are used in a Jakarta Faces application and to store them in scope. The managed bean creation facility is configured in the application configuration resource file using managed-bean XML elements to define each bean. This file is processed at application startup time. For information on using this facility, see Using the managed-bean Element.

Managed beans created in the application configuration resource file are Jakarta Faces managed beans, not CDI managed beans.

With the managed bean creation facility, you can

Create beans in one centralized file that is available to the entire application, rather than conditionally instantiate beans throughout the application
Customize a bean’s properties without any additional code
Customize a bean’s property values directly from within the configuration file so that it is initialized with these values when it is created
Using value elements, set a property of one managed bean to be the result of evaluating another value expression

This section shows you how to initialize beans using the managed bean creation facility. See Writing Bean Properties and Writing Managed Bean Methods for information on programming managed beans.

Using the managed-bean Element

A managed bean is initiated in the application configuration resource file using a managed-bean element, which represents an instance of a bean class that must exist in the application. At runtime, the Jakarta Faces implementation processes the managed-bean element. If a page references the bean and no bean instance exists, the Jakarta Faces implementation instantiates the bean as specified by the element configuration.

Here is an example managed bean configuration from the Duke’s Bookstore case study:

<managed-bean eager="true">
    <managed-bean-name>Book201</managed-bean-name>
    <managed-bean-class>dukesbookstore.model.ImageArea</managed-bean-class>
    <managed-bean-scope>application</managed-bean-scope>
    <managed-property>
        <property-name>shape</property-name>
        <value>rect</value>
    </managed-property>
    <managed-property>
        <property-name>alt</property-name>
        <value>Duke</value>
    </managed-property>
    <managed-property>
        <property-name>coords</property-name>
        <value>67,23,212,268</value>
    </managed-property>
</managed-bean>

The managed-bean-name element defines the key under which the bean will be stored in a scope. For a component’s value to map to this bean, the component tag’s value attribute must match the managed-bean-name up to the first period.

The managed-bean-class element defines the fully qualified name of the JavaBeans component class used to instantiate the bean.

The managed-bean element can contain zero or more managed-property elements, each corresponding to a property defined in the bean class. These elements are used to initialize the values of the bean properties. If you don’t want a particular property initialized with a value when the bean is instantiated, do not include a managed-property definition for it in your application configuration resource file.

If a managed-bean element does not contain other managed-bean elements, it can contain one map-entries element or list-entries element. The map-entries element configures a set of beans that are instances of Map. The list-entries element configures a set of beans that are instances of List.

In the following example, the newsletters managed bean, representing a UISelectItems component, is configured as an ArrayList that represents a set of SelectItem objects. Each SelectItem object is in turn configured as a managed bean with properties:

<managed-bean>
    <managed-bean-name>newsletters</managed-bean-name>
    <managed-bean-class>java.util.ArrayList</managed-bean-class>
    <managed-bean-scope>application</managed-bean-scope>
    <list-entries>
        <value-class>jakarta.faces.model.SelectItem</value-class>
        <value>#{newsletter0}</value>
        <value>#{newsletter1}</value>
        <value>#{newsletter2}</value>
        <value>#{newsletter3}</value>
    </list-entries>
</managed-bean>
<managed-bean>
    <managed-bean-name>newsletter0</managed-bean-name>
    <managed-bean-class>jakarta.faces.model.SelectItem</managed-bean-class>
    <managed-bean-scope>none</managed-bean-scope>
    <managed-property>
        <property-name>label</property-name>
        <value>Duke's Quarterly</value>
    </managed-property>
    <managed-property>
        <property-name>value</property-name>
        <value>200</value>
    </managed-property>
</managed-bean>
...

This approach may be useful for quick-and-dirty creation of selection item lists before a development team has had time to create such lists from the database. Note that each of the individual newsletter beans has a managed-bean-scope setting of none so that they will not themselves be placed into any scope.

See Initializing Array and List Properties for more information on configuring collections as beans.

To map to a property defined by a managed-property element, you must ensure that the part of a component tag’s value expression after the period matches the managed-property element’s property-name element. The next section, Initializing Properties Using the managed-property Element, explains in more detail how to use the managed-property element. See Initializing Managed Bean Properties for an example of initializing a managed bean property.

Initializing Properties Using the managed-property Element

A managed-property element must contain a property-name element, which must match the name of the corresponding property in the bean. A managed-property element must also contain one of a set of elements that defines the value of the property. This value must be of the same type as that defined for the property in the corresponding bean. Which element you use to define the value depends on the type of the property defined in the bean. Subelements of managed-property Elements That Define Property Values lists all the elements that are used to initialize a value.

Subelements of managed-property Elements That Define Property Values
Element	Value It Defines
`list-entries`	Defines the values in a list
`map-entries`	Defines the values of a map
`null-value`	Explicitly sets the property to `null`
`value`	Defines a single value, such as a `String`, `int`, or Jakarta Faces EL expression

Using the managed-bean Element includes an example of initializing an int property (a primitive type) using the value subelement. You also use the value subelement to initialize String and other reference types. The rest of this section describes how to use the value subelement and other subelements to initialize properties of Java Enum types, Map, array, and Collection, as well as initialization parameters.

Referencing a Java Enum Type

A managed bean property can also be a Java Enum type (see https://docs.oracle.com/javase/8/docs/api/java/lang/Enum.html). In this case, the value element of the managed-property element must be a String that matches one of the String constants of the Enum. In other words, the String must be one of the valid values that can be returned if you were to call valueOf(Class, String) on enum, where Class is the Enum class and String is the contents of the value subelement. For example, suppose the managed bean property is the following:

public enum Suit { Hearts, Spades, Diamonds, Clubs }
 ...
public Suit getSuit() { ... return Suit.Hearts; }

Assuming you want to configure this property in the application configuration resource file, the corresponding managed-property element looks like this:

<managed-property>
    <property-name>Suit</property-name>
    <value>Hearts</value>
</managed-property>

When the system encounters this property, it iterates over each of the members of the enum and calls toString() on each member until it finds one that is exactly equal to the value from the value element.

Referencing a Context Initialization Parameter

Another powerful feature of the managed bean creation facility is the ability to reference implicit objects from a managed bean property.

Suppose you have a page that accepts data from a customer, including the customer’s address. Suppose also that most of your customers live in a particular area code. You can make the area code component render this area code by saving it in an implicit object and referencing it when the page is rendered.

You can save the area code as an initial default value in the context initParam implicit object by adding a context parameter to your web application and setting its value in the deployment descriptor. For example, to set a context parameter called defaultAreaCode to 650, add a context-param element to the deployment descriptor and give the parameter the name defaultAreaCode and the value 650.

Next, write a managed-bean declaration that configures a property that references the parameter:

<managed-bean>
    <managed-bean-name>customer</managed-bean-name>
        <managed-bean-class>CustomerBean</managed-bean-class>
        <managed-bean-scope>request</managed-bean-scope>
        <managed-property>
            <property-name>areaCode</property-name>
                <value>#{initParam.defaultAreaCode}</value>
            </managed-property>
            ...
</managed-bean>

To access the area code at the time the page is rendered, refer to the property from the area component tag’s value attribute:

<h:inputText id=area value="#{customer.areaCode}" />

Values are retrieved from other implicit objects in a similar way.

Initializing Map Properties

The map-entries element is used to initialize the values of a bean property with a type of Map if the map-entries element is used within a managed-property element. A map-entries element contains an optional key-class element, an optional value-class element, and zero or more map-entry elements.

Each of the map-entry elements must contain a key element and either a null-value or value element. Here is an example that uses the map-entries element:

<managed-bean>
    ...
    <managed-property>
        <property-name>prices</property-name>
        <map-entries>
            <map-entry>
                <key>My Early Years: Growing Up on *7</key>
                <value>30.75</value>
            </map-entry>
            <map-entry>
                <key>Web Servers for Fun and Profit</key>
                <value>40.75</value>
            </map-entry>
        </map-entries>
    </managed-property>
</managed-bean>

The map created from this map-entries tag contains two entries. By default, all the keys and values are converted to String. If you want to specify a different type for the keys in the map, embed the key-class element just inside the map-entries element:

<map-entries>
    <key-class>java.math.BigDecimal</key-class>
    ...
</map-entries>

This declaration will convert all the keys into java.math.BigDecimal. Of course, you must make sure that the keys can be converted to the type you specify. The key from the example in this section cannot be converted to a BigDecimal, because it is a String.

If you want to specify a different type for all the values in the map, include the value-class element after the key-class element:

<map-entries>
    <key-class>int</key-class>
    <value-class>java.math.BigDecimal</value-class>
    ...
</map-entries>

Note that this tag sets only the type of all the value subelements.

Each map-entry in the preceding example includes a value subelement. The value subelement defines a single value, which will be converted to the type specified in the bean.

Instead of using a map-entries element, it is also possible to assign the entire map using a value element that specifies a map-typed expression.

Initializing Array and List Properties

The list-entries element is used to initialize the values of an array or List property. Each individual value of the array or List is initialized using a value or null-value element. Here is an example:

<managed-bean>
    ...
    <managed-property>
        <property-name>books</property-name>
        <list-entries>
            <value-class>java.lang.String</value-class>
            <value>Web Servers for Fun and Profit</value>
            <value>#{myBooks.bookId[3]}</value>
            <null-value/>
        </list-entries>
    </managed-property>
</managed-bean>

This example initializes an array or a List. The type of the corresponding property in the bean determines which data structure is created. The list-entries element defines the list of values in the array or List. The value element specifies a single value in the array or List and can reference a property in another bean. The null-value element will cause the setBooks method to be called with an argument of null. A null property cannot be specified for a property whose data type is a Java primitive, such as int or boolean.

Initializing Managed Bean Properties

Sometimes you might want to create a bean that also references other managed beans so that you can construct a graph or a tree of beans. For example, suppose you want to create a bean representing a customer’s information, including the mailing address and street address, each of which is also a bean. The following managed-bean declarations create a CustomerBean instance that has two AddressBean properties: one representing the mailing address and the other representing the street address. This declaration results in a tree of beans with CustomerBean as its root and the two AddressBean objects as children.

<managed-bean>
    <managed-bean-name>customer</managed-bean-name>
    <managed-bean-class>
        com.example.mybeans.CustomerBean
    </managed-bean-class>
    <managed-bean-scope> request </managed-bean-scope>
    <managed-property>
        <property-name>mailingAddress</property-name>
        <value>#{addressBean}</value>
    </managed-property>
    <managed-property>
        <property-name>streetAddress</property-name>
        <value>#{addressBean}</value>
    </managed-property>
    <managed-property>
        <property-name>customerType</property-name>
        <value>New</value>
    </managed-property>
</managed-bean>
<managed-bean>
    <managed-bean-name>addressBean</managed-bean-name>
    <managed-bean-class>
        com.example.mybeans.AddressBean
    </managed-bean-class>
    <managed-bean-scope> none </managed-bean-scope>
    <managed-property>
        <property-name>street</property-name>
        <null-value/>
    <managed-property>
    ...
</managed-bean>

The first CustomerBean declaration (with the managed-bean-name of customer) creates a CustomerBean in request scope. This bean has two properties, mailingAddress and streetAddress. These properties use the value element to reference a bean named addressBean.

The second managed bean declaration defines an AddressBean but does not create it, because its managed-bean-scope element defines a scope of none. Recall that a scope of none means that the bean is created only when something else references it. Because both the mailingAddress and the streetAddress properties reference addressBean using the value element, two instances of AddressBean are created when CustomerBean is created.

When you create an object that points to other objects, do not try to point to an object with a shorter life span, because it might be impossible to recover that scope’s resources when it goes away. A session-scoped object, for example, cannot point to a request-scoped object. And objects with none scope have no effective life span managed by the framework, so they can point only to other none-scoped objects. Allowable Connections between Scoped Objects outlines all of the allowed connections.

Allowable Connections between Scoped Objects
An Object of This Scope	May Point to an Object of This Scope
`none`	`none`
`application`	`none`, `application`
`session`	`none`, `application`, `session`
`request`	`none`, `application`, `session`, `request`, `view`
`view`	`none`, `application`, `session`, `view`

Be sure not to allow cyclical references between objects. For example, neither of the AddressBean objects in the preceding example should point back to the CustomerBean object, because CustomerBean already points to the AddressBean objects.

Initializing Maps and Lists

In addition to configuring Map and List properties, you can also configure a Map and a List directly so that you can reference them from a tag rather than referencing a property that wraps a Map or a List.

Registering Application Messages

Application messages can include any strings displayed to the user as well as custom error messages (which are displayed by the message and messages tags) for your custom converters or validators. To make messages available at application startup time, do one of the following:

Queue an individual message onto the jakarta.faces.context.FacesContext instance programmatically, as described in Using FacesMessage to Create a Message
Register all the messages with your application using the application configuration resource file

Here is the section of the faces-config.xml file that registers the messages for the Duke’s Bookstore case study application:

<application>
    <resource-bundle>
        <base-name>
            ee.jakarta.tutorial.dukesbookstore.web.messages.Messages
        </base-name>
        <var>bundle</var>
    </resource-bundle>
    <locale-config>
        <default-locale>en</default-locale>
        <supported-locale>es</supported-locale>
        <supported-locale>de</supported-locale>
        <supported-locale>fr</supported-locale>
    </locale-config>
</application>

This set of elements causes the application to be populated with the messages that are contained in the specified resource bundle.

The resource-bundle element represents a set of localized messages. It must contain the fully qualified path to the resource bundle containing the localized messages (in this case, dukesbookstore.web.messages.Messages). The var element defines the EL name by which page authors refer to the resource bundle.

The locale-config element lists the default locale and the other supported locales. The locale-config element enables the system to find the correct locale based on the browser’s language settings.

The supported-locale and default-locale tags accept the lowercase, two-character codes defined by ISO 639-1 (see https://www.loc.gov/standards/iso639-2/php/English_list.php). Make sure that your resource bundle actually contains the messages for the locales you specify with these tags.

To access the localized message, the application developer merely references the key of the message from the resource bundle.

You can pull localized text into an alt tag for a graphic image, as in the following example:

<h:graphicImage id="mapImage"
                name="book_all.jpg"
                library="images"
                alt="#{bundle.ChooseBook}"
                usemap="#bookMap" />

The alt attribute can accept value expressions. In this case, the alt attribute refers to localized text that will be included in the alternative text of the image rendered by this tag.

Using FacesMessage to Create a Message

Instead of registering messages in the application configuration resource file, you can access the java.util.ResourceBundle directly from managed bean code. The code snippet below locates an email error message:

String message = "";
...
message = ExampleBean.loadErrorMessage(context,
    ExampleBean.EX_RESOURCE_BUNDLE_NAME,
         "EMailError");
context.addMessage(toValidate.getClientId(context),
    new FacesMessage(message));

These lines call the bean’s loadErrorMessage method to get the message from the ResourceBundle. Here is the loadErrorMessage method:

public static String loadErrorMessage(FacesContext context,
     String basename, String key) {
    if ( bundle == null ) {
         try {
            bundle = ResourceBundle.getBundle(basename,
                 context.getViewRoot().getLocale());
        } catch (Exception e) {
            return null;
        }
    }
    return bundle.getString(key);
}

Referencing Error Messages

A Jakarta Faces page uses the message or messages tags to access error messages, as explained in Displaying Error Messages with the h:message and h:messages Tags.

The error messages these tags access include

The standard error messages that accompany the standard converters and validators that ship with the API (see Section 2.5.2.4 of the Jakarta Faces specification for a complete list of standard error messages).
Custom error messages contained in resource bundles registered with the application by the application architect using the resource-bundle element in the configuration file

When a converter or validator is registered on an input component, the appropriate error message is automatically queued on the component.

A page author can override the error messages queued on a component by using the following attributes of the component’s tag:

converterMessage: References the error message to display when the data on the enclosing component cannot be converted by the converter registered on this component.
requiredMessage: References the error message to display when no value has been entered into the enclosing component.
validatorMessage: References the error message to display when the data on the enclosing component cannot be validated by the validator registered on this component.

All three attributes are enabled to take literal values and value expressions. If an attribute uses a value expression, this expression references the error message in a resource bundle. This resource bundle must be made available to the application in one of the following ways:

By the application architect using the resource-bundle element in the configuration file
By the page author using the f:loadBundle tag

Conversely, the resource-bundle element must be used to make available to the application those resource bundles containing custom error messages that are queued on the component as a result of a custom converter or validator being registered on the component.

The following tags show how to specify the requiredMessage attribute using a value expression to reference an error message:

<h:inputText id="ccno" size="19"
    required="true"
    requiredMessage="#{customMessages.ReqMessage}">
    ...
</h:inputText>
<h:message styleClass="error-message" for="ccno"/>

The value expression used by requiredMessage in this example references the error message with the ReqMessage key in the resource bundle customMessages.

This message replaces the corresponding message queued on the component and will display wherever the message or messages tag is placed on the page.

Using Default Validators

In addition to the validators you declare on the components, you can also specify zero or more default validators in the application configuration resource file. The default validator applies to all jakarta.faces.component.UIInput instances in a view or component tree and is appended after the local defined validators. Here is an example of a default validator registered in the application configuration resource file:

<faces-config>
    <application>
        <default-validators>
            <validator-id>jakarta.faces.Bean</validator-id>
        </default-validators>
    <application/>
</faces-config>

Registering a Custom Validator

If the application developer provides an implementation of the jakarta.faces.validator.Validator interface to perform validation, you must register this custom validator either by using the @FacesValidator annotation, as described in Implementing the Validator Interface, or by using the validator XML element in the application configuration resource file:

<validator>
    ...
    <validator-id>FormatValidator</validator-id>
    <validator-class>
        myapplication.validators.FormatValidator
    </validator-class>
    <attribute>
        ...
        <attribute-name>formatPatterns</attribute-name>
        <attribute-class>java.lang.String</attribute-class>
    </attribute>
</validator>

Attributes specified in a validator tag override any settings in the @FacesValidator annotation.

The validator-id and validator-class elements are required subelements. The validator-id element represents the identifier under which the Validator class should be registered. This ID is used by the tag class corresponding to the custom validator tag.

The validator-class element represents the fully qualified class name of the Validator class.

The attribute element identifies an attribute associated with the Validator implementation. It has required attribute-name and attribute-class subelements. The attribute-name element refers to the name of the attribute as it appears in the validator tag. The attribute-class element identifies the Java type of the value associated with the attribute.

Creating and Using a Custom Validator explains how to implement the Validator interface.

Using a Custom Validator explains how to reference the validator from the page.

Registering a Custom Converter

As is the case with a custom validator, if the application developer creates a custom converter, you must register it with the application either by using the @FacesConverter annotation, as described in Creating a Custom Converter, or by using the converter XML element in the application configuration resource file. Here is a hypothetical converter configuration for CreditCardConverter from the Duke’s Bookstore case study:

<converter>
    <description>
        Converter for credit card numbers that normalizes
        the input to a standard format
    </description>
    <converter-id>CreditCardConverter</converter-id>
    <converter-class>
        dukesbookstore.converters.CreditCardConverter
    </converter-class>
</converter>

Attributes specified in a converter tag override any settings in the @FacesConverter annotation.

The converter element represents a jakarta.faces.convert.Converter implementation and contains required converter-id and converter-class elements.

The converter-id element identifies an ID that is used by the converter attribute of a UI component tag to apply the converter to the component’s data. Using a Custom Converter includes an example of referencing the custom converter from a component tag.

The converter-class element identifies the Converter implementation.

Creating and Using a Custom Converter explains how to create a custom converter.

Configuring Navigation Rules

Navigation between different pages of a Jakarta Faces application, such as choosing the next page to be displayed after a button or link component is clicked, is defined by a set of rules. Navigation rules can be implicit, or they can be explicitly defined in the application configuration resource file. For more information on implicit navigation rules, see Navigation Model.

Each navigation rule specifies how to navigate from one page to another page or set of pages. The Jakarta Faces implementation chooses the proper navigation rule according to which page is currently displayed.

After the proper navigation rule is selected, the choice of which page to access next from the current page depends on two factors:

The action method invoked when the component was clicked
The logical outcome referenced by the component’s tag or returned from the action method

The outcome can be anything the developer chooses, but Common Outcome Strings lists some outcomes commonly used in web applications.

Common Outcome Strings
Outcome	What It Means
`success`	Everything worked. Go on to the next page.
`failure`	Something is wrong. Go on to an error page.
`login`	The user needs to log in first. Go on to the login page.
`no results`	The search did not find anything. Go to the search page again.

Usually, the action method performs some processing on the form data of the current page. For example, the method might check whether the user name and password entered in the form match the user name and password on file. If they match, the method returns the outcome success. Otherwise, it returns the outcome failure. As this example demonstrates, both the method used to process the action and the outcome returned are necessary to determine the correct page to access.

Here is a navigation rule that could be used with the example just described:

<navigation-rule>
    <from-view-id>/login.xhtml</from-view-id>
    <navigation-case>
        <from-action>#{LoginForm.login}</from-action>
        <from-outcome>success</from-outcome>
        <to-view-id>/storefront.xhtml</to-view-id>
    </navigation-case>
    <navigation-case>
        <from-action>#{LoginForm.logon}</from-action>
        <from-outcome>failure</from-outcome>
        <to-view-id>/logon.xhtml</to-view-id>
    </navigation-case>
</navigation-rule>

This navigation rule defines the possible ways to navigate from login.xhtml. Each navigation-case element defines one possible navigation path from login.xhtml. The first navigation-case says that if LoginForm.login returns an outcome of success, then storefront.xhtml will be accessed. The second navigation-case says that login.xhtml will be re-rendered if LoginForm.login returns failure.

The configuration of an application’s page flow consists of a set of navigation rules. Each rule is defined by the navigation-rule element in the faces-config.xml file.

Each navigation-rule element corresponds to one component tree identifier defined by the optional from-view-id element. This means that each rule defines all the possible ways to navigate from one particular page in the application. If there is no from-view-id element, the navigation rules defined in the navigation-rule element apply to all the pages in the application. The from-view-id element also allows wildcard matching patterns. For example, this from-view-id element says that the navigation rule applies to all the pages in the books directory:

<from-view-id>/books/*</from-view-id>

A navigation-rule element can contain zero or more navigation-case elements. The navigation-case element defines a set of matching criteria. When these criteria are satisfied, the application will navigate to the page defined by the to-view-id element contained in the same navigation-case element.

The navigation criteria are defined by optional from-outcome and from-action elements. The from-outcome element defines a logical outcome, such as success. The from-action element uses a method expression to refer to an action method that returns a String, which is the logical outcome. The method performs some logic to determine the outcome and returns the outcome.

The navigation-case elements are checked against the outcome and the method expression in the following order.

Cases specifying both a from-outcome value and a from-action value. Both of these elements can be used if the action method returns different outcomes depending on the result of the processing it performs.
Cases specifying only a from-outcome value. The from-outcome element must match either the outcome defined by the action attribute of the jakarta.faces.component.UICommand component or the outcome returned by the method referred to by the UICommand component.
Cases specifying only a from-action value. This value must match the action expression specified by the component tag.

When any of these cases is matched, the component tree defined by the to-view-id element will be selected for rendering.

Registering a Custom Renderer with a Render Kit

When the application developer creates a custom renderer, as described in Delegating Rendering to a Renderer, you must register it using the appropriate render kit. Because the image map application implements an HTML image map, the AreaRenderer and MapRenderer classes in the Duke’s Bookstore case study should be registered using the HTML render kit.

You register the renderer either by using the @FacesRenderer annotation, as described in Creating the Renderer Class, or by using the render-kit element of the application configuration resource file. Here is a hypothetical configuration of AreaRenderer:

<render-kit>
    <renderer>
        <component-family>Area</component-family>
        <renderer-type>DemoArea</renderer-type>
        <renderer-class>
            dukesbookstore.renderers.AreaRenderer
        </renderer-class>
        <attribute>
            <attribute-name>onmouseout</attribute-name>
            <attribute-class>java.lang.String</attribute-class>
        </attribute>
        <attribute>
            <attribute-name>onmouseover</attribute-name>
            <attribute-class>java.lang.String</attribute-class>
        </attribute>
        <attribute>
            <attribute-name>styleClass</attribute-name>
            <attribute-class>java.lang.String</attribute-class>
        </attribute>
    </renderer>
    ...

Attributes specified in a renderer tag override any settings in the @FacesRenderer annotation.

The render-kit element represents a jakarta.faces.render.RenderKit implementation. If no render-kit-id is specified, the default HTML render kit is assumed. The renderer element represents a jakarta.faces.render.Renderer implementation. By nesting the renderer element inside the render-kit element, you are registering the renderer with the RenderKit implementation associated with the render-kit element.

The renderer-class is the fully qualified class name of the Renderer.

The component-family and renderer-type elements are used by a component to find renderers that can render it. The component-family identifier must match that returned by the component class’s getFamily method. The component family represents a component or set of components that a particular renderer can render. The renderer-type must match that returned by the getRendererType method of the tag handler class.

By using the component family and renderer type to look up renderers for components, the Jakarta Faces implementation allows a component to be rendered by multiple renderers and allows a renderer to render multiple components.

Each of the attribute tags specifies a render-dependent attribute and its type. The attribute element doesn’t affect the runtime execution of your application. Rather, it provides information to tools about the attributes the Renderer supports.

The object responsible for rendering a component (be it the component itself or a renderer to which the component delegates the rendering) can use facets to aid in the rendering process. These facets allow the custom component developer to control some aspects of rendering the component. Consider this custom component tag example:

<d:dataScroller>
    <f:facet name="header">
        <h:panelGroup>
            <h:outputText value="Account Id"/>
            <h:outputText value="Customer Name"/>
            <h:outputText value="Total Sales"/>
        </h:panelGroup>
    </f:facet>
    <f:facet name="next">
        <h:panelGroup>
            <h:outputText value="Next"/>
            <h:graphicImage url="/images/arrow-right.gif" />
        </h:panelGroup>
    </f:facet>
    ...
</d:dataScroller>

The dataScroller component tag includes a component that will render the header and a component that will render the Next button. If the renderer associated with this component renders the facets, you can include the following facet elements in the renderer element:

<facet>
    <description>This facet renders as the header of the table. It should be
         a panelGroup with the same number of columns as the data.
    </description>
    <display-name>header</display-name>
    <facet-name>header</facet-name>
</facet>
<facet>
    <description>This facet renders as the content of the "next" button in
         the scroller. It should be a panelGroup that includes an outputText
         tag that has the text "Next" and a right arrow icon.
    </description>
    <display-name>Next</display-name>
    <facet-name>next</facet-name>
</facet>

If a component that supports facets provides its own rendering and you want to include facet elements in the application configuration resource file, you need to put them in the component’s configuration rather than the renderer’s configuration.

Registering a Custom Component

In addition to registering custom renderers (as explained in the preceding section), you also must register the custom components that are usually associated with the custom renderers. You use either a @FacesComponent annotation, as described in Creating Custom Component Classes, or the component element of the application configuration resource file.

Here is a hypothetical component element from the application configuration resource file that registers AreaComponent:

<component>
    <component-type>DemoArea</component-type>
    <component-class>
        dukesbookstore.components.AreaComponent
    </component-class>
    <property>
        <property-name>alt</property-name>
        <property-class>java.lang.String</property-class>
    </property>
    <property>
        <property-name>coords</property-name>
        <property-class>java.lang.String</property-class>
    </property>
    <property>
        <property-name>shape</property-name>
        <property-class>java.lang.String</property-class>
    </property>
</component>

Attributes specified in a component tag override any settings in the @FacesComponent annotation.

The component-type element indicates the name under which the component should be registered. Other objects referring to this component use this name. For example, the component-type element in the configuration for AreaComponent defines a value of DemoArea, which matches the value returned by the AreaTag class’s getComponentType method.

The component-class element indicates the fully qualified class name of the component. The property elements specify the component properties and their types.

If the custom component can include facets, you can configure the facets in the component configuration using facet elements, which are allowed after the component-class elements. See Registering a Custom Renderer with a Render Kit for further details on configuring facets.

Basic Requirements of a Jakarta Faces Application

In addition to configuring your application, you must satisfy other requirements of Jakarta Faces applications, including properly packaging all the necessary files and providing a deployment descriptor. This section describes how to perform these administrative tasks.

Jakarta Faces applications can be packaged in a WAR file, which must conform to specific requirements to execute across different containers. At a minimum, a WAR file for a Jakarta Faces application may contain the following:

A web application deployment descriptor, called web.xml, to configure resources required by a web application (required)
A specific set of JAR files containing essential classes (optional)
A set of application classes, Jakarta Faces pages, and other required resources, such as image files

A WAR file may also contain:

An application configuration resource file, which configures application resources
A set of tag library descriptor files

For example, a Jakarta Faces web application WAR file using Facelets typically has the following directory structure:

$PROJECT_DIR
[Web Pages]
+- /[xhtml or html documents]
+- /resources
+- /WEB-INF
   +- /web.xml
   +- /beans.xml (optional)
   +- /classes (optional)
   +- /lib (optional)
   +- /faces-config.xml (optional)
   +- /*.taglib.xml (optional)
   +- /glassfish-web.xml (optional)

The web.xml file (or web deployment descriptor), the set of JAR files, and the set of application files must be contained in the WEB-INF directory of the WAR file.

Configuring an Application with a Web Deployment Descriptor

Web applications are commonly configured using elements contained in the web application deployment descriptor, web.xml. The deployment descriptor for a Jakarta Faces application must specify certain configurations, including the following:

The servlet used to process Jakarta Faces requests
The servlet mapping for the processing servlet
The path to the configuration resource file, if it exists and is not located in a default location

The deployment descriptor can also include other, optional configurations, such as those that

Specify where component state is saved
Encrypt state saved on the client
Compress state saved on the client
Restrict access to pages containing Jakarta Faces tags
Turn on XML validation
Specify the Project Stage
Verify custom objects

This section gives more details on these configurations. Where appropriate, it also describes how you can make these configurations using NetBeans IDE.

Identifying the Servlet for Lifecycle Processing

A requirement of a Jakarta Faces application is that all requests to the application that reference previously saved Jakarta Faces components must go through jakarta.faces.webapp.FacesServlet. A FacesServlet instance manages the request-processing lifecycle for web applications and initializes the resources required by Jakarta Faces technology.

Before a Jakarta Faces application can launch its first web page, the web container must invoke the FacesServlet instance in order for the application lifecycle process to start. See The Lifecycle of a Jakarta Faces Application for more information.

The following example shows the default configuration of the FacesServlet:

<servlet>
    <servlet-name>Faces Servlet</servlet-name>
    <servlet-class>jakarta.faces.webapp.FacesServlet</servlet-class>
</servlet>

You will provide a mapping configuration entry to make sure that the FacesServlet instance is invoked. The mapping to FacesServlet can be a prefix mapping, such as /faces/, or an extension mapping, such as .xhtml. The mapping is used to identify a page as having Jakarta Faces content. Because of this, the URL to the first page of the application must include the URL pattern mapping.

The following elements specify a prefix mapping:

<servlet-mapping>
    <servlet-name>Faces Servlet</servlet-name>
    <url-pattern>/faces/*</url-pattern>
</servlet-mapping>
...
<welcome-file-list>
    <welcome-file>faces/greeting.xhtml</welcome-file>
</welcome-file-list>

The following elements, used in the tutorial examples, specify an extension mapping:

<servlet-mapping>
    <servlet-name>Faces Servlet</servlet-name>
    <url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
...
<welcome-file-list>
    <welcome-file>index.xhtml</welcome-file>
</welcome-file-list>

When you use this mechanism, users access the application as shown in the following example:

http://localhost:8080/guessNumber

In the case of extension mapping, if a request comes to the server for a page with an .xhtml extension, the container will send the request to the FacesServlet instance, which will expect a corresponding page of the same name containing the content to exist.

To minimize clutter and allow simple, friendly URLs, you can have extensionless URLs by manually exact mapping the FacesServlet to the existing prefix and suffix mapping options in web.xml, one or more times.

If you are using NetBeans IDE to create your application, a web deployment descriptor is automatically created for you with default configurations. If you created your application without an IDE, you can create a web deployment descriptor.

To Specify a Path to an Application Configuration Resource File

As explained in Application Configuration Resource File, an application can have multiple application configuration resource files. If these files are not located in the directories that the implementation searches by default or the files are not named faces-config.xml, you need to specify paths to these files.

To specify these paths using NetBeans IDE, do the following.

Expand the node of your project in the Projects tab.
Expand the Web Pages and WEB-INF nodes that are under the project node.
Double-click web.xml.
After the web.xml file appears in the editor, click General at the top of the editor window.
Expand the Context Parameters node.
Click Add.
In the Add Context Parameter dialog box:
1. Enter jakarta.faces.CONFIG_FILES in the Parameter Name field.
2. Enter the path to your configuration file in the Parameter Value field.
3. Click OK.
4. Repeat steps 1 through 7 for each configuration file.

To Specify Where State Is Saved

For all the components in a web application, you can specify in your deployment descriptor where you want the state to be saved, on either client or server. You do this by setting a context parameter in your deployment descriptor. By default, state is saved on the server, so you need to specify this context parameter only if you want to save state on the client. See Saving and Restoring State for information on the advantages and disadvantages of each location.

To specify where state is saved using NetBeans IDE, do the following.

Expand the node of your project in the Projects tab.
Expand the Web Pages and WEB-INF nodes under the project node.
Double-click web.xml.
After the web.xml file appears in the editor window, click General at the top of the editor window.
Expand the Context Parameters node.
Click Add.
In the Add Context Parameter dialog box:
1. Enter jakarta.faces.STATE_SAVING_METHOD in the Parameter Name field.
2. Enter client or server in the Parameter Value field.
3. Click OK.

If state is saved on the client, the state of the entire view is rendered to a hidden field on the page. The Jakarta Faces implementation saves the state on the server by default. Duke’s Forest saves its state on the client.

Configuring Project Stage

Project Stage is a context parameter identifying the status of a Jakarta Faces application in the software lifecycle. The stage of an application can affect the behavior of the application. For example, error messages can be displayed during the Development stage but suppressed during the Production stage.

The possible Project Stage values are as follows:

Development
UnitTest
SystemTest
Production

Project Stage is configured through a context parameter in the web deployment descriptor file. Here is an example:

<context-param>
    <param-name>jakarta.faces.PROJECT_STAGE</param-name>
    <param-value>Development</param-value>
</context-param>

If no Project Stage is defined, the default stage is Production. You can also add custom stages according to your requirements.

Including the Classes, Pages, and Other Resources

When packaging web applications using the included build scripts, you’ll notice that the scripts package resources in the following ways.

All web pages are placed at the top level of the WAR file.
The faces-config.xml file and the web.xml file are packaged in the WEB-INF directory.
All packages are stored in the WEB-INF/classes/ directory.
All application JAR files are packaged in the WEB-INF/lib/ directory.
All resource files are either under the root of the web application /resources directory or in the web application’s classpath, the META-INF/resources/resourceIdentifier directory. For more information on resources, see Web Resources.

When packaging your own applications, you can use NetBeans IDE or you can use XML files such as those created for Maven. You can modify the XML files to fit your situation. However, you can continue to package your WAR files by using the directory structure described in this section, because this technique complies with the commonly accepted practice for packaging web applications.