Skip to main content

Real Ajax for Real Java Developers: GWT & jQUERY

In this days every Ajax application uses jQuery or Dojo or something like this. If you ask me jQuery is the most often framework because it is small, it helps a lot, it has cool features and it is promoted by Microsoft (we live in strange days). jQuery can be used for many things one of them is effects. We all know how Flash, Silverilght and JavaFX “Rich UI” look and often with CSS and JavaScript it’s very hard to make things that can be done in easy in flash. The jQuery helps a lot with it fade effects slideUp/slideDown and etc. I as a Java Developer I like GWT but often I use JSF too. When I use JSF I’ve always add JQuery because at certain point I’ve always  need to type some javascript and with jquery its easier. When I use GWT I’ve wanted to be able to use JQuery the same way like I’ve use it in JSF app or even better. The solution is GWTQuery or GQuery: http://code.google.com/p/gwtquery/ . From the website we can see That Gwt Query is a jQuery-like API written in GWT, which allows GWT to be used in progressive enhancement scenarios where perhaps GWT widgets are too heavyweight.

When I saw this I said: “awesome”. You can read how to get started from here http://code.google.com/p/gwtquery/wiki/GettingStarted I will not explain how to setup and use gwt query because in the wiki you will get up2date information about possible changes but the result is awesome.

Lets assume that we have a table and we want to hide it when the user clicks a button or link but with some transition effect like fade. To do this I use gwt plugin for eclipse from google  and created a simple project. My welcome-file GwtJQuery.html looks like this:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<!-- The HTML 4.01 Transitional DOCTYPE declaration-->
<!-- above set at the top of the file will set -->
<!-- the browser's rendering engine into -->
<!-- "Quirks Mode". Replacing this declaration -->
<!-- with a "Standards Mode" doctype is supported, -->
<!-- but may lead to some differences in layout. -->

<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">

<!-- -->
<!-- Consider inlining CSS to reduce the number of requested files -->
<!-- -->
<link type="text/css" rel="stylesheet" href="GwtJQuery.css">

<!-- -->
<!-- Any title is fine -->
<!-- -->
<title>Web Application Starter Project</title>

<!-- -->
<!-- This script loads your compiled module. -->
<!-- If you add any GWT meta tags, they must -->
<!-- be added before this line. -->
<!-- -->
<script type="text/javascript" language="javascript" src="gwtjquery/gwtjquery.nocache.js"></script>
</head>

<!-- -->
<!-- The body can have arbitrary html, or -->
<!-- you can leave the body empty if you want -->
<!-- to create a completely dynamic UI. -->
<!-- -->
<body>

<!-- OPTIONAL: include this if you want history support -->
<iframe src="javascript:''" id="__gwt_historyFrame" tabIndex='-1' style="position:absolute;width:0;height:0;border:0"></iframe>

<h1>Web Application Starter Project</h1>

<table align="center" bgcolor="yellow" id="table">
<tr>
<td colspan="2" style="font-weight:bold;">Please enter your name:</td>
</tr>
<tr>
<td id="nameFieldContainer"></td>
<td id="sendButtonContainer"></td>
<td id="hideButtonContainer"></td>
</tr>
</table>
</body>
</html>



The only changes from the base project are the script tag for gwtquery,  the id for the table with value “table” and one new column with id hideButtonContainer. The new code is only this:




...
final Button hideButton=new Button("Hide");
...
RootPanel.get("hideButtonContainer").add(hideButton);
...
hideButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
hideContainer();
}
});
...
protected void hideContainer() {
$("table").css("background-color", "grey");
$("table").click(new Function() {
@Override
public boolean f(Event e) {
$(e).as(Effects).fadeOut();
return true;
}
});
}
...



We have hideButton, we add it to the RootPanel and we have clickHandler that invokes method called hideContainer. The methods uses GWTQuery which looks like jquery and what we do: we are make instant changing of the background-color to grey and fade effect on the table. You can read the getting started guide of gwt query for more info but the result looks like this:











Comments

Popular Posts

Hibernate Generic DAO.

When you use Hibernate and DAO pattern it is a good idea to use a Generic Base Dao. The fallowing code snippet contains GenericDAO that is a base class for all my DAO classes. This GenericDAO uses HibernateDaoSupport from Spring for its implementation if you want you can use JpaDaoSupport or JdbcDaoSupport in your projects. My Generic DAO interface looks like this : package org.joke.myproject.dao.base; import java.io.Serializable; import java.util.List; /** * @author Naiden Gochev * @param <E> * @param <PK> */ public interface GenericDao<E,PK  extends Serializable> {     PK save(E newInstance);     void update(E transientObject);     void saveOrUpdate(E transientObject);     void delete(E persistentObject);     E findById(PK id);     List<E> findAll();     List<E> f...

JavaEE 5 (JSF + JPA + EJB3) using Eclipse

Today I will show you how to create Enterprise Application using Java EE 5 and GlassFish. I will use - Eclipse 3.5 + WTP - GlassFish v. 2.1 - JSF Mojarra implementation. - EJB 3.0. - JPA Toplink essentials implementation. - MySQL No NetBeans or JDeveloper magic involved :) The prerequirement is: Add datasource in glassfish. Read this how you can make this here: http://gochev.blogspot.com/2009/10/creating-datasource-in-glassfish-v-21.html 1) First you need to add glassfish in your eclipse. - Go to Servers View - Right Click, New - Choose GlassFish v 2.1 if you dont have glassfish click on Download additional adapters link choose glassfish wait and restart eclipse. Than try again. 2) Create the database CREATE TABLE ` lesson ` . ` USERS ` ( ` id ` INTEGER UNSIGNED NOT NULL AUTO_INCREMENT, ` username ` VARCHAR ( 45 ) NOT NULL , ` password ` VARCHAR ( 45 ) NOT NULL , ` name ` VARCHAR ( 45 ) NOT NULL , PRIMARY KEY ( ` id ` ) ) ENGINE = InnoDB...

Generate JavaDoc with UML diagrams

In my life many times has happened when I am assigned to a totally new project that I have no idea what it is about, that has to go live in 2 weeks and that I have to fix some issues in this ultra strange code sometimes even code written in different language. On my question is there any documentation the answer is: Yes but it is very old or no. So in short they want me to start working on a project with no documentation at all. My second question is is there a javadoc and the anwer is : yeah … kind of … so I am in a project with 30% javadoc with methods in French language for example ( I don’t know even a single word in French) so in short I am loosing 2 weeks to understand what is using what what is the model what is PersonnePhysique  and what is this crazy domain model. I believe this has happened with everyone of you at least once so what can you do ? You can start digging into the java code like crazy ( like everyone of us have tried many times) You can install ...