Getting Started with PrimeFaces

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Setting up and configuring the PrimeFaces library

PrimeFaces is a lightweight JSF component library with one JAR file, which needs no configuration and does not contain any required external dependencies. To start with the development of the library, all we need is to get the artifact for the library.

Getting ready

You can download the PrimeFaces library from http://primefaces.org/downloads.html and you need to add the primefaces-{version}.jar file to your classpath. After that, all you need to do is import the namespace of the library, which is necessary to add the PrimeFaces components to your pages, to get started.

If you are using Maven (for more information on installing Maven, please visit http://maven.apache.org/guides/getting-started/maven-in-five-minutes.html), you can retrieve the PrimeFaces library by defining the Maven repository in your Project Object Model (POM) file as follows:

<repository> <id>prime-repo</id> <name>PrimeFaces Maven Repository</name> <url>http://repository.primefaces.org</url> </repository>

Add the dependency configuration as follows:

<dependency>
<groupId>org.primefaces</groupId>
<artifactId>primefaces</artifactId>
<version>3.4</version>
</dependency>

At the time of writing this book, the latest and most stable version of PrimeFaces was 3.4. To check out whether this is the latest available or not, please visit http://primefaces.org/downloads.html The code in this book will work properly with PrimeFaces 3.4. In prior versions or the future versions, some methods, attributes, or components’ behaviors may change.

How to do it…

In order to use PrimeFaces components, we need to add the namespace declarations into our pages. The namespace for PrimeFaces components is as follows:

For PrimeFaces Mobile, the namespace is as follows:

That is all there is to it. Note that the p prefix is just a symbolic link and any other character can be used to define the PrimeFaces components. Now you can create your first page with a PrimeFaces component as shown in the following code snippet:

<html > <f:view contentType="text/html"> <h:head /> <h:body> <h:form> <p:spinner /> </h:form> </h:body> </f:view> </html>

This will render a spinner component with an empty value as shown in the following screenshot:

A link to the working example for the given page is given at the end of this recipe.

How it works…

When the page is requested, the p:spinner component is rendered with the renderer implemented by the PrimeFaces library. Since the spinner component is a UI input component, the request-processing lifecycle will get executed when the user inputs data and performs a post back on the page.

For the first page, we also needed to provide the contentType parameter for f:view, since the WebKit-based browsers, such as Google Chrome and Apple Safari, request the content type application/xhtml+xml by default. This would overcome unexpected layout and styling issues that might occur.

There’s more…

PrimeFaces only requires Java 5+ runtime and a JSF 2.x implementation as mandatory dependencies. There are some optional libraries for certain features.

Dependency

Version

Type

Description

JSF runtime

iText

Apache POI

Rome

commons-fileupload

commons-io

2.0 or 2.1

2.1.7

3.7

1.0

1.2.1

1.4

Required

Optional

Optional

Optional

Optional

Optional

Apache MyFaces or Oracle Mojarra

DataExporter (PDF)

DataExporter (Excel)

FeedReader

FileUpload

FileUpload

Please ensure that you have only one JAR file of PrimeFaces or specific PrimeFaces Theme in your classpath in order to avoid any issues regarding resource rendering.

Currently PrimeFaces supports the web browsers IE 7, 8, or 9, Safari, Firefox, Chrome, and Opera.

PrimeFaces Cookbook Showcase application

This recipe is available in the PrimeFaces Cookbook Showcase application on GitHub at https://github.com/ova2/primefaces-cookbook. You can find the details there for running the project. When the server is running, the showcase for the recipe is available at http://localhost:8080/primefaces-cookbook/views/chapter1 /yourFirstPage.jsf”

AJAX basics with Process and Update

PrimeFaces provides a partial page rendering (PPR) and view-processing feature based on standard JSF 2 APIs to enable choosing what to process in the JSF lifecycle and what to render in the end with AJAX. PrimeFaces AJAX Framework is based on standard server-side APIs of JSF 2. On the client side, rather than using the client-side API implementations of JSF implementations, such as Mojarra and MyFaces, PrimeFaces scripts are based on the jQuery JavaScript library.

How to do it…

We can create a simple page with a command button to update a string property with the current time in milliseconds on the server side and an output text to show the value of that string property, as follows:

<p:commandButton update="display" action="#{basicPPRController. updateValue}" value="Update" /> <h:outputText id="display" value="#{basicPPRController.value}"/>

If we would like to update multiple components with the same trigger mechanism, we can provide the IDs of the components to the update attribute by providing them a space, comma, or both, as follows:

<p:commandButton update="display1,display2" /> <p:commandButton update="display1 display2" /> <p:commandButton update="display1,display2 display3" />

In addition, there are reserved keywords that are used for a partial update. We can also make use of these keywords along with the IDs of the components, as described in the following table:

Keyword

Description

@this

The component that triggers the PPR is updated

@parent

The parent of the PPR trigger is updated

@form

The encapsulating form of the PPR trigger is updated

@none

PPR does not change the DOM with AJAX response

@all

The whole document is updated as in non-AJAX requests

We can also update a component that resides in a different naming container from the component that triggers the update. In order to achieve this, we need to specify the absolute component identifier of the component that needs to be updated. An example for this could be the following:

<h:form id="form1"> <p:commandButton update=":form2:display" action="#{basicPPRController.updateValue}" value="Update" /> </h:form> <h:form id="form2"> <h:outputText id="display" value="#{basicPPRController.value}"/> </h:form> public String updateValue() { value = String.valueOf(System.currentTimeMillis()); return null; }

PrimeFaces also provides partial processing, which executes the JSF lifecycle phases—Apply Request Values, Process Validations, Update Model, and Invoke Application—for determined components with the process attribute. This provides the ability to do group validation on the JSF pages easily. Mostly group-validation needs arise in situations where different values need to be validated in the same form, depending on an action that gets executed. By grouping components for validation, errors that would arise from other components when the page has been submitted can be overcome easily. Components like commandButton, commandLink, autoComplete, fileUpload, and many others provide this attribute to process partially instead of the whole view.

Partial processing could become very handy in cases when a drop-down list needs to be populated upon a selection on another drop down and when there is an input field on the page with the required attribute set to true. This approach also makes immediate subforms and regions obsolete. It will also prevent submission of the whole page, thus this will result in lightweight requests. Without partially processing the view for the drop downs, a selection on one of the drop downs will result in a validation error on the required field. An example for this is shown in the following code snippet:

<h:outputText value="Country: " /> <h:selectOneMenu id="countries" value="#{partialProcessingController. country}"> <f:selectItems value="#{partialProcessingController.countries}" /> <p:ajax listener= "#{partialProcessingController.handleCountryChange}" event="change" update="cities" process="@this"/> </h:selectOneMenu> <h:outputText value="City: " /> <h:selectOneMenu id="cities" value="#{partialProcessingController. city}"> <f:selectItems value="#{partialProcessingController.cities}" /> </h:selectOneMenu> <h:outputText value="Email: " /> <h:inputText value="#{partialProcessingController.email}" required="true" />

With this partial processing mechanism, when a user changes the country, the cities of that country will be populated in the drop down regardless of whether any input exists for the email field.

How it works…

As seen in partial processing example for updating a component in a different naming container, <p:commandButton> is updating the <h:outputText> component that has the ID display, and absolute client ID :form2:display, which is the search expression for the findComponent method. An absolute client ID starts with the separator character of the naming container, which is : by default.

The <h:form>, <h:dataTable>, composite JSF components along with <p:tabView>, <p:accordionPanel>, <p:dataTable>, <p:dataGrid>, <p:dataList>, <p:carousel>, <p:galleria>, <p:ring>, <p:sheet>, and <p:subTable> are the components that implement the NamingContainer interface. The findComponent method, which is described at http://docs.oracle.com/javaee/6/api/javax/faces/component/UIComponent.html, is used by both JSF core implementation and PrimeFaces.

There’s more…

JSF uses : (a colon) as the separator for the NamingContainer interface. The client IDs that will be rendered in the source page will be like :id1:id2:id3. If needed, the configuration of the separator can be changed for the web application to something other than the colon with a context parameter in the web.xml file of the web application, as follows:

<context-param> <param-name>javax.faces.SEPARATOR_CHAR</param-name> <param-value>_</param-value> </context-param>

It’s also possible to escape the : character, if needed, in the CSS files with the character, as :. The problem that might occur with the colon is that it’s a reserved keyword for the CSS and JavaScript frameworks, like jQuery, so it might need to be escaped.

PrimeFaces Cookbook Showcase application

This recipe is available in the PrimeFaces Cookbook Showcase application on GitHub at https://github.com/ova2/primefaces-cookbook. You can find the details there for running the project. For the demos of the showcase, refer to the following:

  • Basic Partial Page Rendering is available at http://localhost:8080/ primefaces-cookbook/views/chapter1/basicPPR.jsf

  • Updating Component in Different Naming Container is available at http://localhost:8080/primefaces-cookbook/views/chapter1/ componentInDifferentNamingContainer.jsf

  • A Partial Processing example at http://localhost:8080/primefacescookbook/ views/chapter1/partialProcessing.jsf

Internationalization (i18n) and Localization (L10n)

Internationalization (i18n) and Localization (L10n) are two important features that should be provided in the web application’s world to make it accessible globally.

With Internationalization, we are emphasizing that the web application should support multiple languages; and with Localization, we are stating that the texts, dates, or any other fields should be presented in the form specific to a region.

PrimeFaces only provides the English translations. Translations for the other languages should be provided explicitly. In the following sections, you will find the details on how to achieve this.

Getting ready

For Internationalization, first we need to specify the resource bundle definition under the application tag in faces-config.xml, as follows:

<application> <locale-config> <default-locale>en</default-locale> <supported-locale>tr_TR</supported-locale> </locale-config> <resource-bundle> <base-name>messages</base-name> <var>msg</var> </resource-bundle> </application>

A resource bundle would be a text file with the .properties suffix that would contain the locale-specific messages. So, the preceding definition states that the resource bundle messages_{localekey}.properties file will reside under classpath and the default value of localekey is en, which is English, and the supported locale is tr_TR, which is Turkish. For projects structured by Maven, the messages_{localekey}.properties file can be created under the src/main/resources project path.

How to do it…

For showcasing Internationalization, we will broadcast an information message via FacesMessage mechanism that will be displayed in the PrimeFaces growl component. We need two components, the growl itself and a command button, to broadcast the message.

<p:growl id="growl" /> <p:commandButton action="#{localizationController.addMessage}" value="Display Message" update="growl" />

The addMessage method of localizationController is as follows:

public String addMessage() { addInfoMessage("broadcast.message"); return null; }

That uses the addInfoMessage method, which is defined in the static MessageUtil class as follows:

public static void addInfoMessage(String str) { FacesContext context = FacesContext.getCurrentInstance(); ResourceBundle bundle = context.getApplication(). getResourceBundle(context, "msg"); String message = bundle.getString(str); FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO, message, "")); }

Localization of components, such as calendar and schedule, can be achieved by providing the locale attribute. By default, locale information is retrieved from the view’s locale and it can be overridden by a string locale key or the java.util.Locale instance.

Components such as calendar and schedule use a shared PrimeFaces.locales property to display labels. PrimeFaces only provides English translations, so in order to localize the calendar we need to put corresponding locales into a JavaScript file and include the scripting file to the page.

The content for the German locale of the Primefaces.locales property for calendar would be as shown in the following code snippet. For the sake of the recipe, only the German locale definition is given and the Turkish locale definition is omitted.

PrimeFaces.locales['de'] = { closeText: 'Schließen', prevText: 'Zurück', nextText: 'Weiter', monthNames: ['Januar', 'Februar', 'März', 'April', 'Mai', 'Juni', 'Juli', 'August', 'September', 'Oktober', 'November', 'Dezember'], monthNamesShort: ['Jan', 'Feb', 'Mär', 'Apr', 'Mai', 'Jun', 'Jul', 'Aug', 'Sep', 'Okt', 'Nov', 'Dez'], dayNames: ['Sonntag', 'Montag', 'Dienstag', 'Mittwoch', 'Donnerstag', 'Freitag', 'Samstag'], dayNamesShort: ['Son', 'Mon', 'Die', 'Mit', 'Don', 'Fre', 'Sam'], dayNamesMin: ['S', 'M', 'D', 'M ', 'D', 'F ', 'S'], weekHeader: 'Woche', FirstDay: 1, isRTL: false, showMonthAfterYear: false, yearSuffix: '', timeOnlyTitle: 'Nur Zeit', timeText: 'Zeit', hourText: 'Stunde', minuteText: 'Minute', secondText: 'Sekunde', currentText: 'Aktuelles Datum', ampm: false, month: 'Monat', week: 'Woche', day: 'Tag', allDayText: 'Ganzer Tag' };

Definition of the calendar components with the locale attribute would be as follows:

<p:calendar showButtonPanel="true" navigator="true" mode="inline" id="enCal"/> <p:calendar locale="tr" showButtonPanel="true" navigator="true" mode="inline" id="trCal"/> <p:calendar locale="de" showButtonPanel="true" navigator="true" mode="inline" id="deCal"/>

They will be rendered as follows:

How it works…

For Internationalization of the Faces message, the addInfoMessage method retrieves the message bundle via the defined variable msg. It then gets the string from the bundle with the given key by invoking the bundle.getString(str) method. Finally, the message is added by creating a new Faces message with severity level FacesMessage.SEVERITY_INFO.

There’s more…

For some components, Localization could be accomplished by providing labels to the components via attributes, such as with p:selectBooleanButton.

<p:selectBooleanButton value="#{localizationController.selectedValue}" onLabel="#{msg['booleanButton.onLabel']}" offLabel="#{msg['booleanButton.offLabel']}" />

The msg variable is the resource bundle variable that is defined in the resource bundle definition in Faces configuration file. The English version of the bundle key definitions in the messages_en.properties file that resides under classpath would be as follows:

booleanButton.onLabel=Yes booleanButton.offLabel=No

PrimeFaces Cookbook Showcase application

This recipe is available in the PrimeFaces Cookbook Showcase application on GitHub at https://github.com/ova2/primefaces-cookbook. You can find the details there for running the project. For the demos of the showcase, refer to the following:

  • Internationalization is available at http://localhost:8080/primefacescookbook/ views/chapter1/internationalization.jsf

  • Localization of the calendar component is available at http://localhost:8080/ primefaces-cookbook/views/chapter1/localization.jsf

  • Localization with resources is available at http://localhost:8080/ primefaces-cookbook/views/chapter1/localizationWithResources. jsf

For already translated locales of the calendar, see https://code.google.com/archive/p/primefaces/wikis/PrimeFacesLocales.wiki

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