Book Image

PrimeFaces Cookbook

Book Image

PrimeFaces Cookbook

Overview of this book

PrimeFaces is the de facto standard in the Java web development. PrimeFaces is a lightweight library with one jar, zero-configuration, and no required dependencies. You just need to download PrimeFaces, add the primefaces-{version}.jar to your classpath and import the namespace to get started. This cookbook provides a head start by covering all the knowledge needed for working with PrimeFaces components in the real world. "PrimeFaces Cookbook" covers over 100 effective recipes for PrimeFaces 3.x which is a leading component suite to boost JSF applications. The book's range is wide‚Äí from AJAX basics, theming, and input components to advanced usage of datatable, menus, drag & drop, and charts. It also includes creating custom components and PrimeFaces Extensions.You will start with the basic concepts such as installing PrimeFaces, configuring it, and writing a first simple page. You will learn PrimeFaces' theming concept and common inputs and selects components. After that more advanced components and use cases will be discussed. The topics covered are grouping content with panels, data iteration components, endless menu variations, working with files and images, using drag & drop, creating charts, and maps. The last chapters describe solutions for frequent, advanced scenarios and give answers on how to write custom components based on PrimeFaces and also show the community-driven open source project PrimeFaces Extension in action.
Table of Contents (17 chapters)
PrimeFaces Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Polling – sending periodical AJAX requests


Polling is a way to poll a server periodically in order to trigger some server-side changes or update parts of a web page. The polling technology in PrimeFaces is represented by the Poll component. It is an AJAX component that has an ability to send periodical AJAX requests.

In this recipe, we will update a feed reader periodically to show current sports news. A Growl component will be updated with the same interval too, in order to show the time of the last feed update.

How to do it...

The p:poll component in the following code snippet invokes the listener method showMessage() every 10 seconds and updates a feed reader and growl. The listener method generates the current time. Furthermore, we will define a widget variable in order to stop or start polling, using the client-side API. This occurs via command buttons.

<p:growl id="growl"/>

<p:poll id="poll" listener="#{pollingController.showMessage}"
  update="sportFeed growl" interval...