GWT

There's nothing particularly unusual about that, but as you'll see in a moment, GWT uses those identifiers as a place to put elements.

However, GWT is something of an all-or-nothing approach, targeted at a relatively small niche in Web application development market.

GWT: If I were hungry, I would not tell you, because the world and all that it contains are mine.

In the meantime, head over to the GWT download site and try it out for yourself.

When running tests, you must pass in at least one VM argument to help specify which GWT mode (hosted or Web) to run the test in.

As of this writing, advanced tool support for GWT is beginning to emerge in the major Java development environments.

GWT: But he moved on, and now there is no trace of him.

GWT requires an asynchronous version of any interface that's going to be invoked from the client.

Cypal Studio for GWT has a couple of handy features to make it even easier for you to create and manage a remote connection.

The entry point into a GWT application is a Java class whose compiled JavaScript is the script for a given page.

Didier: GWT is very easy to use, a Java developer can develop Web application without learning any new technologies.

The framework I'm talking about is, of course, the immensely popular Google Web Toolkit, also known as the GWT.

As you can see, you simply call your GWT method once the body of the page has loaded.

Although you can extend basic GWT controls with a set of custom properties, this path often requires significant development effort.

It was the reason that I started gwt-ext a while ago when Ext was LGPL.

GWT: Faith led Abraham to obey when God called him to go to a place that he would receive as an inheritance.

I'm going to sidetrack a little here to mention that the GWT Shell has JVM hooks that let you debug your client-side code in a Java IDE.

The two versions must be in the same package, and that package must be visible to your GWT client code.

I'm hoping to limit my use of the accessors because, as I've already mentioned, the GWT isn't meant to be used for interaction testing.

Let's take a look at how the GWT compiler can help with that.

One of the most important tools provided in GWT is the Remove URL tool, which allows you to remove invalid pages from Google search results.

This article examines a simple GWT application that solves both the getting and processing parts of the problem.

First, you need the Ext GWT JAR (gxt, jar, part of the Ext GWT download) to be on your classpath.

You've seen how GWT can be used for creating UI elements and using Ajax to retrieve and save data to back-end services.

It's very easy to customize the tree images for the GWT Tree widget.

So far, all of the optimizations that we have looked at were language-level optimizations made by the GWT compiler.

This option is made possible by a Slicr. launch file that GWT created and that you imported into Eclipse with the rest of the project.

Even if it did, regular expressions in GWT have syntactical differences when deployed as client and server code.

Everything has been straighforward and the GWT has been "vanilla" so far, and you might be wondering why you're bothering to show this here.

GWT provides a simple programming model at design time, but a highly optimized runtime implementation.

For each remote service, GWT requires two interfaces on the client side: a remote service interface and a remote service async interface.

The module is the basic unit of your GWT code and is referenced by the HTML pages that your client uses.

The Java class is in your client package, meaning that it's intended to be compiled by GWT into JavaScript code.

Note: The original distribution of GWT did not include this file.

You can also use Sitebricks to deliver XML and Json to GWT applications, just like you would to any other client service.

So far, GWT has helped me deliver more performance, but there is one area in which it could even make performance worse: caching.

Without getting too deeply into the details of the GWT widget set, this code creates a button and a label.

GWT: Jeremiah went into a prison cell , and he stayed there a long time.

At the time, I casually alluded to "a couple of shell scripts" created along with the GWT project files but didn't go into more detail.

If you do decide to use GWT into a J2EE application environment, GWT's design should make integration relatively straightforward.

As you use GWT, some other files are placed in the GWT home directory to manage your temporary files.

However, the potential exists for a whole class of attacks against GWT applications dealing in more sensitive data.

It's only a few steps: GWT Client generator, GWT model generator, and you'll have your GWT client ready.

You are going to use GWT to make an Ajax request to a remote service, so your trigger is calling JavaScript instead.

This will allow you to simplify your page, and you'll simplify it even more by using GWT JSNI to dynamically create your XForms controls.

Prior to GWT, client-server interactions were more complicated to program, and of course you couldn't use Java code for the client.

GWT's deferred binding architecture allows it to compile multiple versions of JavaScript for the various browsers.

An initial approach to the actual GWT module could look like what you see in Listing 1, but how would you test this code?

When testing via GWTTestCase, I'm best off not attempting to manually force a state change on a component, but rather letting GWT do it.

Even after four articles, you've only scratched the surface of what GWT has to offer.

RIA and GWT in particular is a revolution in terms of user experience and in terms of development experience too !

GWT is designed to be a multi-purpose framework for building Web applications.

Finally, you saw one of the lesser-known, but powerful, features of GWT: Java-style sorting.

Let's take a look at how you can do that programmatically through GWT as well.

Most examples that you'll see of GWT show "green field" applications, in other words, applications built from scratch using GWT.

A remote procedure mechanism allows for communication between client and server, with GWT handling all the pipe and data translation.

This article introduces several performance problems and provides GWT-appropriate solutions that you can use in your own Web sites.

Injection of JavaScript files and stylesheets is a convenient way to associate external files automatically with your GWT module.

gwt : just as drought and heat steal water from snow , so the grave steals people who sin.

GWT allows you to easily access server-side servlets by using Remote Procedure Calls (RPCs).

It also contains several other interfaces, classes, and image files that are used to create the GWT Web interface.

Obviously, this constrains the portability of a compiled GWT Web application.

GWT abstracts this communication process behind its own remote procedure call (RPC) mechanism.

The GWT is a comprehensive set of APIs and tools that lets you create dynamic Web applications in Java code.

InfoQ will continue reporting new development among the GWT open source development community.

When you trigger a GWT compile, it will bring up the dialog shown in Figure 1.

The demo application requires that you install the GWT SDK on your system.

In May you blogged about your decision to step down from the gwt-ext project due to the controversial licensing changes with ExtJS.

In the next sections, I'll walk you through the example GWT application.

Most importantly, JavaScript is the key into and out of the GWT world.

The key is remembering that some of the Java code you write in your GWT application is essentially untrustworthy at run time.

Because Ajax is inherently asynchronous, GWT defines an asynchronous interface for accessing remote services.

Because the remote service call is asynchronous and non-blocking, the GWT client does not wait for a response from the service.

Future articles will show you how to set up the Derby database and connect the GWT front end to the Derby-based back end.

GWT does this through code generation: The GWT compiler generates cross-browser compatible JavaScript from client-side Java code.

You've spent a lot of time on the albums' page of your application, combining the capabilities of GWT and XForms.

GWT: Also pray that we may be rescued from worthless and evil people, since not everyone shares our faith.

Using XML instead of a relational database will keep it simple so you can focus on the real stars of the application: GWT and XForms.

One of the ideas behind GWT is that you can write your code using software engineering best practices.

Some GWT proponents suggest that writing client-side code in the Java language is intrinsically preferable to writing JavaScript.

Let's take a look at how to do this GWT style, as shown in Listing 15.

The community has been very understanding and the other team leaders of gwt-ext have also stepped up and done a great job.

In the interest of focusing on Derby and GWT here, I present a quick converter that serves during the start of development.

You've defined some new controls for your data entry form, but you can once again make use of GWT and JSNI to create these new controls.

The example application is a GUI done in GWT that talks to a greeting service application.

You'll see one example in Resources, and the various Java IDEs are increasingly adding GWT support, including deployment.

GWT is well known for its ability to compile Java into JavaScript, enabling Java developers to develop dynamic Web applications.

So far you've been testing your GWT artists page using GWT's hosted dode.

Web mode is the full deployment mode; it's what you would use after you compile your GWT program to JavaScript code.

You have a nice GWT widget ready to use for displaying your list of artists.

You have a nice GWT widget ready to use for displaying your list of artists.

If you look through the list of plug-ins, you'll see support for such RIA clients as Flex, OpenLazlo, GWT, and ZK.

All implementing test classes must reside in the same package as the GWT module you're attempting to test.

GWT: Evildoers will be cut off from their inheritance, but those who wait with hope for the LORD will inherit the land.

Also, your parameters and return value must be of types that GWT can serialize.

GWT: Look at our shield, O God. Look with favor on the face of your anointed one.

GWT also creates a Slicr. launch file that Eclipse uses as well as a couple of shell scripts.

However, even if your Web server is using gzip, you will still get a significant boost from GWT obfuscation.

This makes them fully compatible with commercial controls and JavaScript libraries.

Callback examples in most GWT books and online tutorials are implemented as anonymous inner classes.

The module name is essentially the package structure where your GWT XML file resides minus the file extensions.

Now let's take a look at what the GWT compiler will emit for various browsers.

However, the first parameter of all GWT's Listener methods is the event's sender, usually the widget that the user just interacted with.

GWT can dramatically improve your productivity and enrich your users' experience.

For newer versions of Firefox, GWT compiles the Java code into JavaScript that uses the textContent property of the element.

Mixing GWT elements will not only simplify the server-side code, it will create smaller initial pages, with faster downloads and rendering.

Let's start by looking at the entry point to the GWT-powered application.

The three . gif files are, as you might expect from their names, used by GWT in rendering tree widgets.

There's an extra JAR for the GWT app that wasn't necessary for the servlet-based one, namely gwt-servlet. jar.

The default mode is obfuscated, in that the GWT compiler will emit obfuscated JavaScript.

GWT parses the contents of the comment block and outputs the JavaScript verbatim.

To your slicr directory, move both your GWT-compiled JavaScript pages and your normally compiled Java classes.

Probably the most contentious issue in GWT's architecture is the switch to the Java language for client-side code.

Now let's examine how you can use GWT to create a UI for a list of Artist objects.

This article discussed design patterns that provide ways to accelerate your GWT application by leveraging the use of Ajax in the background.

You'll use a GWT-style Ajax call to load your data dynamically and then use GWT's JSNI to dynamically create your XForms model.

That's actually your nice, neat Java code compiled to JavaScript code by the GWT compiler.

As of this writing, the exciting GWT news is the V1. 3 release of a fully open source GWT.

In Part 2, you'll create a small contact-management application using App Engine for Java's support for servlets and GWT, respectively.

You're putting everything in a GWT Grid, so you must set the size of the grid when you create it.

The demo application archive contains all required libraries except GWT.

The key to testing GWT applications well (as is true of most applications) is to design the application with testing in mind.

You can launch in hosted mode once again, but you'll need to switch over to GWT's Web Mode for testing your new page.

The gwt. js and nocache. html files both contain more or less boilerplate code designed to start and load your GWT application properly.

Widget support in GWT-WL includes calendars, calculators, image buttons, progress bars, pagination, and more.

GWT: We wanted to visit you. I, Paul, wanted to visit you twice already, but Satan made that impossible.

MyGWT is a plugin to GWT which wraps its native UI components with a ExtJS skin.

This file contains all the GWT user files that your application needs.

Here you'll learn how to set up GWT and create a simple client interface that responds to user actions.

Notice how GWT support is unselected for this first simple example.

You can use the designer to help you build interfaces using the GWT.

With GWT, you can create your form programmatically, as shown in Listing 8.

GWT: In this way you show that you are children of your Father in heaven.

When designing and building GWT applications, you must think about testing the code without relying on user interactions.

Separately we plan on progressing some of the Generation IV webapp requirements (technologies such as Flex and GWT).

With GWT, this is as easy as creating a simple Java bean, as shown in Listing 1.

In hosted mode, GWT automatically simulates your remote calls.

GWT's run-time JavaScript library uses this file to initialize the application.

With GWT, you can develop Ajax applications in the Java programming language.

Dojo, GWT and OpenLazlo do a great job with their widget toolkits, but do not have a broad application platform to offer.

GWT applications can acquire the polished ExtJS look and feel using this tool.

One of the nice things with GWT is that you can use hosted mode.

Also note that Google's internal open sourced widget toolset, GWT, allows them to replicate any desktop capability.

GWT's conflation of client-side and server-side code is inherently dangerous.

The GWT plug-in in Eclipse automatically creates a sample remote service.

This article is not an introduction to GWT, so prior experience with GWT is assumed.

In GWT, a Tree widget contains TreeItem widgets, which are usually used as tree nodes.

In Part 2 of this series, you used GWT to load a list of artists on a page.

GWT: The mouth of the righteous person reflects on wisdom. His tongue speaks what is fair.

In this final installment in the GWT and XForms series, you saw how to add interactive forms to your application.

You should compare the startup speed of the GWT mail sample to other sample Ajax applications.

In this article, I demonstrated how to use GWT tree widgets to display the organizational structure of a company.

WindowBuilder allows GUI-based development of SWT and Swing applications, and has recently been updated to support GWT 2. 0 as well.

Next, you need to make slight modifications to the base HTML page that GWT generates.

You use the familiar Listener pattern to perform event handling in GWT.

Thus, if your Web server is not using gzip, you will obviously get a big speed boost by using GWT obfuscation.

Now recall that GWT runs as JavaScript, and so any calls a GWT application makes to remote servers is limited by the same-origin policy.

You used GWT's Ajax mechanism to load data from the server asynchronously.

Luckily GWT also includes widgets for creating forms.

This method prints a log message to the shell window for GWT hosted mode.

You then used GWT's JSNI facilities to dynamically create the instance data in your XForm's model.

The second argument to the call, which is an instance of NumberCallback, GWT invokes automatically when the server completes its response.

This lets you use GWT independent of server technologies.

Once we release the GWT version, it will be interesting to observe what our viewers prefer.

GWT's most unique feature is that you can create your Ajax application and still write your code in the Java language.

GWT will decide when it can run the next step of the calculation.

In addition, GWT has modified the web. xml file to register the new remote server for use in deployed applications.

If the RESTful Web service server is running on the same domain and port, the obvious option is using the GWT RequestBuilder class.

Now, we will alter the following code from the GWT start project, shown in Listing 4.

The exact details of how to set up your GWT project differ depending on whether you plan to use an IDE.

Like MyGWT, GWT-Ext also supports a variety of back-end data sources for its components.

Each cell in the grid can contain either plain text or another GWT widget.

You can get early access to these features by building the GWT trunk source code.

See Resources for in-depth documentation, including how GWT works and how to create simple applications.

Ofcourse the gwt-ext project will continue to run the way it currently is.

This is a naming convention that lets GWT match up this interface to the one shown in Listing 4.

[@gwt. eventArgs was previously used as] javadoc-based metadata for RPC.

This window contains error and log messages from GWT.

Because you have no tree widgets in the Slicr application, you can assume that GWT always puts these images in your output.

Internationalization is also a major problem for GWT.

Client side GWT uses the Java language to generate JavaScript; The heavy server side platform never makes it into the picture.

You're also dependent on GWT's code-generation being bug-free.

In earlier releases, GWT provided a lot of event listener interfaces.

Another thing to be aware of is that GWT 1. 5 now fully supports the 'long' primitive data type.

This isn't possible with the black box of GWT (see the Licensing sidebar).

GWT provides the $wnd and $doc variables to refer to the window and document objects.

The directory above contains an important file called Slicr. gwt. xml.

In this article, you worked through the process of creating a single RPC using GWT.

The GWT compiler has three modes of operation.

Figure 1 shows a sample GWT interface that mimics a desktop e-mail application.

Make Tomcat aware of all the server-side actions you call from your GWT page.

As a result, you can test your GWT applications earlier and hopefully more often.

Next up, compile and move your GWT client files.

I think also that GWT is particularly suited for high traffic.

Because the GWT JSON library is used to parse out the JSON string, you need to include it in the GWT module configuration file (Listing 14).

SmartGWT also uses the standard GWT 1. 6 event API which is much cleaner and flexible compared to its predecessor.

The bulk of the work in your GWT procedure call happens in two classes.

GWT: Do I eat the meat of bulls or drink the blood of goats?

This class creates GWT GUI elements and associates them with HTML DOM elements on the SimpleGWTApp. html (see Listing 10).

Today SFEIR is developing five GWT based applications and we already have several in productions.

Logging - The logging API may make it into GWT 2. 1 if time permits.

We simply set the user. agent property to gecko1_8 and now GWT will only do one compile that produces JavaScript targeted for Firefox V3 .

Eventually, the server will eke out a response, and only at that point does your GWT code do the wonderful thing you have planned.

This is somewhat similar to the anonymous inner-class idiom used by GWT's event handlers.

Fortunately, GWT was built to play nice with other technologies.

The first article in this series focuses on GWT.

To figure out how to do this I actually copied a lot of ideas from Googles GWT project build process.

The basic idea here is that you carefully tell the GWT system which remote service you're calling.

However, it's probably best to use a simple naming convention, such as the GWT name of the actual service.

The library is not ready for GWT trunk, but this project is worth pursuing.

The basic unit of GWT code is the module.

We have a first GWT prototype of the Parleys. com client.

This is a pretty typical GWT application using its core components.

GWT client code must be compatible with Java 1. 4.

As you work in GWT, you'll be spending a lot of time in hosted mode.

This time, however, you will use the GWT.

I've tested it with all major GWT releases, including version 1. 3.

GWT provides a very easy way to implement it.

This is the first release with the support of GWT open source contributors.

To use this CSS file and it's images in your application you need to use the StyleInjector class from the GWT incubator project.

It's a great example because it's a change most people will encounter early on as they upgrade to GWT 1. 5.

RAP is very different to something like GWT.

It probably comes as no surprise that GWT uses a unique format that is highly optimized.

What is the primary difference between gwt-ext and SmartGWT?

This is a simple example of GWT's localization.

At base, GWT is a compiler.

For example, there's no straightforward way to submit the selected value from a GWT Tree widget as part of a regular form.

So this begs the question, how do you add GWT to an existing Web page?

There are other more browser-specific optimizations that can be done by GWT.

Form Validation - We will take a closer look at the form validation API in GWT 2. 2.

Ext includes a Grid widget that is much richer than the GWT table.

For GWT we want to add the header to each file that doesn't match *. nocache. *.

GWT's latest version is 2. 0. 3 and it was released in February this year.

This is mostly just the file that is generated by the GWT applicationCreator script, but you have added two lines to it.

This article uses GWT version 1. 4 and the Mozilla XForms plugin 0. 8 (see the Resources for download links).

So that is where we will begin our exploration of GWT's performance-related features.

Doing so invokes GWT hosted mode for your project. (After doing this once, clicking Run will work just like any other Eclipse run target. )

InfoQ: GWT is about two years old, you have been following and using this technology since its inception, where are we today?

Eclipse with GWT support is the environment used for developing the GWT application in this article. In Eclipse

You just have to implement the Serializable interface and force GWT deferred binding on client side (see the associated guide for details)

As an example, I use the following image bundle for the basic images in a couple applications I've helped build

Other open source or commercial projects developed in the GWT ecosystem are

There are four elements in this . html file that identify it as a file used by GWT. They are

Each line is a critical step in your GWT call. Here's the checklist

Number and Date Formatting in GWT

How to retrieve an XML document using the GWT