Groovy and GWT: Combining both paradigms - gwt

Is it possible to develop an application in groovy using GWT components?
Luis

If you want to use Groovy on the server-side and GWT for the UI, that is certainly possible. You can use Grails (a Groovy web framework on the server), and the Grails GWT plugin to help you integrate GWT with this framework.

I don't think so, because the GWT compiler is basically a Java to JavaScript source compiler (it would be possible if the GWT compiler needed Java bytecode). You can use Groovy on the server side though.

Right now you cant use Groovy on the client side. One big reason is that Groovy relies a lot on introspection, and this is not available on GWT.

I have also wondered this, as it would be very nice. Vaadin essentially does this and you can use their plugin: http://grails.org/plugin/vaadin
Doing it this model, though, it is compiling components into Javascript and delivering from the server. But unlike GWT components, these are calling back to the server every time you touch the API (though of course with Vaadin you can use GWT components as well).

Related

writing netbeans RCP apps on scala

Have anyone tried to write a Netbeans RCP application in scala (Instead of Java). The reason for my question there is an API in Scala which wraps JavaFX. Likewise is there any API to make to develop Netbeans RCP based apps written in scala.
For wrapping JavaFX there is ScalaFX. Netbeans Rich Client Platform is not small, and a Scala wrapper seems impractical to me (I am not aware of any); just call the Java code from Scala. Java/Scala interoperability is generally decent, so while you might occasionally have to write a little bit of Java as an interface, you can pretty much just use Scala for any Java project.
(Getting the build process to work might be a little tricky, though; expect to invest a little time there.)
I personally dont see any useful use case to use JVM language to develop NB RCP/Plugin. NB It self provides a IDE where you can use the drag-drop feature, codegen, annotation based IDE to created it. If you want to have a syntax sugar in writing NB RCP then i feel its waste of time where we already have a good IDE. JVM is not going to do any much difference that the existing environment.
If you see that you need a NB like modular, GUI based framework in Scala ecosystem that, I personally feel writing binding wont solve that problem. Scala need some framework like Griffon.

widget based web framework for scala

I am trying to move from java to scala . I am basically a web developer where i use zkoss, vaadin as my framework. Do scala has widget based framework.Fully ajax based? I haven't tried lift and play need some advice is that fully ajax based?
The Vaadin framework can be used with Scala. There is even a project called Scaladin to help you with that. Since you already know it, I suggest you try learning scala with that framework. After you have a good understand of scala you should have a better base for what framework to choose in case you want to leave Vaadin.
Here are some resources:
Scala and Vaadin HOWTO
Scaladin wiki
Develop Vaadin apps with Scala
Try Scala+GWT with one of web frameworks (Lift, Play and etc.)

GWT Special Features compared to other Frameworks

I am on searching special features of GWT which are present only in GWT and not in other web framework. I am a student and I am not well acquainted to the many web frameworks on the market, so if u can help me increasing my list of special GWT features, it would be a great help. Some which i know are:
1. GWT allows using java to program
web. (only, it also allows merging
javascript through JSNI of course)
2. The developer does not have to be a guru in browser incompatibilities
to develop web sites which works on
a variety of browsers because
incompatibilities are handled by GWT
through differed bindind
3. GWT allows easy integration of popular Java Tools such as ,
hibernate through gilead
4. GWT enables server implementation not only in java but also other
languages such as php
5. GWT enables code splitting which improves application interactivity
by allowing javaScript file to
download only when required
6. In essence GWT is toolkit, it does not force a way to program,
other layers can be placed on top of
it to program such as placing MVP or
MVC framework on top of GWT and then
develop app
7. GWT MVP is great because first it allows collaborative working, faster
testing with JUnit and the event bus
allows many updates in client side
application by placing event on the
event bus
8. GWT compiled java files to obfuscated mode which is first small
and make the application safer
because bots fails on the javascript
generated during the obfuscated mode
In case in the 8 points, i've mention something which not special to GWT, then let me know.
There's also 'perfect caching', which is the term used to describe the way that GWT optimises JavaScript for each browser.
Instead of building a large JavaScript file, with code that can handle all of the various browsers, GWT builds multiple JavaScript files at compile time, and downloads only the one that is relevant to the browser type that is being used.
EDIT: Every time you make a change to your Java code, GWT changes the name of the corresponding JavaScript file. Web servers can turn on caching for the JavaScript files (so that browsers won't re-download the same file), assured that the name will change when the Java code changes, and the browser will then download the latest version.
EDIT: I also really like the CssResource feature. By creating obfuscated CSS style names, GWT effectively gives each widget its own namespace for CSS styles; for example, I could define a 'pretty' style name on two different widgets, and have those styles using different CSS rules. Of course, it is possible to share CSS styles between widgets too.
Image resources are cool too. They optimise the way that images are downloaded and accessed.
Don't forget internationalization.
I think you pulled together a pretty decent list of differentiators there already. I think that one point worth adding is the RequestFactory feature in the most recent release, which, if you will, is simplistically speaking and RPC for data and makes it quite easy to develop Create, Read, Update and Delete - type (CRUD) of applications.
There are other, more important/wider accepted GUI-Frameworks that are based on Java.
There are for example Struts and JSF. That's why some of your points don't fit only for GWT, but for all GUI java frameworks in general, e.g. bullet point 1, 2 & 3.
But to add another one:
I think GWT is an easy way to code an AJAX-application, because it hides the AJAX stuff quite well. Wouldn't you agree?
Furthermore, GWT is a proprietary framework (which is somehow a unique property). JSF is standardized and Struts is lead by Apache.

GWT: UiBinder or GWT Designer?

I have my first GWT project that I created using UiBinder (GWT 2.0 way) which I found to be easier than write my UI creation Java source code (GWT 1.0 way).
But I saw this thing called GWT Designer that Google are releasing for free. It has nice features and wizards which were missing with the standard Google Eclipse Plugin. I like it, but I still think that using UiBinder is better. I think GWT Designer will be really useful when it can help you write UiBinder XML files (GWT 2.0 way), and not just source code (GWT 1.0 way).
What do you think about it?
Do I need to migrate to GWT Designer project?
Will it be better if I migrate but still keep UiBinder UI creation?
The latest GWT Designer now has support for UiBinder, and it works great.
http://download.instantiations.com/D2GWTDoc/continuous/latest/docs/html/wizards/gwt/uibinder_composite.html
UiBinder can give you better performance and a better optimized download than traditional widget construction; to me that's enough of a reason to stick with UiBinder. If your app is light and fast enough as it is then the choice probably comes down to what style of development suits you best.
I wouldn't go as far as to port your existing UiBinder templates into the designer. Google will be adding support for them to GWT designer soon enough.
I haven't used the newly-freed GWT Designer yet myself, but I wouldn't expect that it would warrant migrating your entire project over to it if it's already written using UIBinder.
Remember that the two methods of constructing a UI are not mutually exclusive -- you can use the GWT Designer to create a new widget and use it in an existing UIBinder project, and if you decide it's that much better, you can consider migrating at that point. Or not, since they can still happily coexist.
If you are doing professional development in an organization that utilizes experts in CSS and html, then GWt is going to be a tough sell if you don't use something like UIBinder for layouting as well as individual pages. I also think that a CSS designer can do a better job at responding to UI requirement changes than a java developer using GWT layouting techniques.
However if your java staff has control of the requirements and don't have to answer to UI designers, then I suppose choosing between delcarative templates and something like GWT Designer is just a matter preference.
As said in the relaunch announcement:
Now that these products are available again, we hope you’ll start using them within your GWT projects. Meanwhile, our next step is to more deeply unify them into the GWT family of tools by blending the fantastic Instantiations technology into the Google Plugin for Eclipse (GPE). So, there’s much more to come, including things we’re pretty sure you’ll like, such as UiBinder support in GWT Designer.
It wouldn't make sense to get ride of your UiBinder code since GWT Designer will support it soon.
DON'T use the designer plugin. The most recent update (8.1.1 at the time of this post) contains buttons that allow the user to add elements that are incompatible with IE, for instance CellTable, DeckPanel, HorizontalPanel and VerticalPanel.
This means whoever uses the plugin, uses it entirely at their peril. If IE7 tries to pull in these elements, it will load a partial page but fail to load components that use these elements. IE8 may not be able to load the application at all.

Developing Eclipse plugins without Java

Is it possible to create Eclipse plugins/program Eclipse RCP apps without Java? (preferably in Jython)
This will be possible in the next Eclipse major release e4:
One of the goals of e4 is to provide support for writing plugins in other languages.
The quote is from http://wiki.eclipse.org/E4/JavaScript which summarizes the current state of using javascript to implement eclipse plug-ins in e4.
This issue in eclipse's bugzilla issue #227058 also has some discussion on that, but I believe it is outdated.
I am currently not aware of activity regarding other languages.
No. An Eclipse plugin is an OSGi bundle, and that requires interacting with a variety of things that can't implemented in Jython as far as I can see.
If you want to avoid Java, you can look at other things that target the JVM, but you will have to figure if you can produce and consume the specific items needed to call the necessary things and be called in the necessary ways.
OSGi bundles may be written in other JVM languages like Scala. Eclipse plug-ins, as of now, does not support any language other than Java. The Eclipse Plug-in Development Environment heavily makes use of JDT which ties it to Java. However there are some plans I heard that plug-ins might be supported in other languages. But I don't see that coming in near future.
You can write your main code in Jython and use Java interfaces to call then from Java. Take a look at this for details. Also, I am writing a utility library (github.com/abhin4v/jywrapper) to do the same. It has very little documentation right now, but you can look at the examples provided.