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JSF- Java Server Faces |
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Using Ajax in Apache MyFaces
Ajax, or AJAX, is a web development technique used
for creating interactive web applications. The intent is to
make web pages feel more responsive by exchanging
small amounts of data with the server behind the scenes,
so that the entire web page does not have to be reloaded
each time the user requests a change. This is
intended to increase the web page’s interactivity, speed,
functionality, and usability.
Ajax is a cross-platform technology compatible with different
operating systems, computer architectures, and web browsers
as it is based on open standards such as JavaScript and
XML, together with open source implementations of other
required technologies.
Ajax has a big name in the field of web development. One of
the biggest advantages of Ajax is that it really improves web
application user experience. Ajax is highly compatible with
various technologies like HTML, JSP, JSF (Java Server Faces)
etc. Traditionally, when the user requests for the page, the
entire web page is rendered while in the case of Ajax only a
portion of page is rendered.
What is Ajax?
Ajax is a new approach for creating interactive web applications.
It is an acronym for “Asynchronous JavaScript and
XML”. Ajax is a bundle of commonly used technologies:
1 HTML (or XHTML) and CSS
2 Document Object Model (DOM)
3 XML
4 JavaScript, XMLHttpRequest Object
Hence, Ajax is not a new technology. An Ajax application
looks as if it resideson the user’s machine. Data is asynchronously
fetched and browser is updated with the gathered
information rather than refreshing the entire page i.e. partial
refreshing of a page.
Two technologies that will enhance Rich Internet Applications:
AJAX is a perfect match for the JSF presentation tier
because of its rich component model. Simply use JSF
AJAX components to add AJAX functionality to a JSF
application.
JavaServer(tm) Faces (JSF) is an established web application
framework standard (JSR127) that accomplishes the MVC
paradigm. JSF is comparable to the well-known Struts
framework but has features and concepts that are beyond
those of Struts. MyFaces Core is a 100% compliant implementation
of this standard - it is compliant to the standard yet |
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offers additional value by providing separate extended component
sets and many special features which make JSF development
easier.
MyFaces has several subprojects, where MyFaces API and
MyFaces Impl together comprise the core implementation.
Tomahawk (MyFacesComponents), Tobago (Tobago) and
Trinidad (Trinidad) are sets of extended components. These
components offers you more functionality and flexibility than
using the standard components of the core implementation.
Integrating AJAX in Java Server Faces (MyFaces) :
Apache MyFaces has a sub-project named “Sandbox” which
provides a set of components. Sandbox is a new addition to
the Tomahawk project. This helps us to easily integrate Ajax
enabled components in MyFaces. To let the sandbox components
work, we have to add “tomahawk-sandbox-1.1.6-
SNAPSHOT .jar” file in lib folder of your application along with
complete set of jar files for JSF (MyFaces) environment to run
application.
Download “tomahawk-sandbox-1.1.6-SNAPSHOT.jar” file:
“tomahawk-sandbox-1.1.6-SNAPSHOT.jar” file can be downloaded
from http://people.apache.org/builds/myfaces/nightly/
tomahawk-sandbox-1.1.6-SNAPSHOT-bin.zip address. Just
unzip the file, pick the jar file from the lib folder and copy it to
the lib folder of your application. Restart the server and start
using sandbox components in your application.
Example of using Ajax in MyFaces through Sandbox component
Auto Complete example:
In this example, user can only enter the name of a
state (from U.S.). As soon as the user enters any string
matching the states name, a drop down list comes in the
picture. That helps to select the state from there.
Sandbox provides a very nice component InputSuggestAjax
that is a very good example of using Ajax in MyFaces. We
have nothing to do just simply use the tag for the component
in the view page and create backing bean to provide functionality
for selecting the list of appropriate states matching the
string entered by the user in the page. Just follow these steps:
1 Create View page (JSP file)
2 Create JSF managed bean
Creating JSP file:
<%@ taglib uri=”http://java.sun.com/jsf/html” prefix=”h”%>
<%@ taglib uri=”http://java.sun.com/jsf/core” prefix=”f”%>
<%@ taglib uri=”http://myfaces.apache.org/tomahawk”
prefix=”t”%>
<%@ taglib uri=”http://myfaces.apache.org/sandbox”
prefix=”s”%>
<f:view> |
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August 2007 | Java Jazz Up |15 |
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| Pages: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, |
| 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Download PDF |
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