Generally I believe the idea of writing code in one language to be converted into another is wrong. Languages are tools to do a job - pick the right one for the job or it will end in tears.
It takes a lot of discipline to work on large JS code bases, and writing Java instead of JS could be a good choice for some projects if developer skill set is leaning towards Java.
Also, it seems that there is a fraction in Google which likes Java, hates JavaScript and has enough resources to go with projects that bring Java to browser like GWT or Darts.
Personally, if they already like Java so hard, why they don't "just" create nice JRE/browser/DOM integration package so we could use any JVM language instead of JavaScript.
Or if you do, you will have to concede that it is wrong to write anything but assembler code.
Thus, the likelihood is that converting Java into Javascript or Pl/SQL into LISP or ActionScript into Python will provide no benefit but will almost certainly complicate the development process.
As for the JavaScript side, if you find it daunting, you may try Coffeescript or even Closure (which provides some Java-developer-friendly limits to JavaScript).
Java has its strengths, but writing web applications isn't among them.
So...was GWT developed for Java web developers that didn't want to learn Javascript? Javascript is just one of the things you have to know how to use to build a modern web site or web application.
The comparison with Ruby and Python isn't really fair. A better comparison is C#, which is like Java in spirit but has a large number of incremental improvements over Java.
Underlying it all, Java has an attitude that concision doesn't matter. One reason why people don't do anything interesting with generics because you always have to write
GenericContainer<AnotherGenericContainer<ArbitaryTypeA>,AbitraryTypeB> = new GenericContainer<AnotherGenericContainer<ArbitaryTypeA>,AbitraryTypeB>();
C# has var, extension methods, function pointers, generics without type erasure and many other little things that show respect for the programmer. You realize then that the "problem with Java" isn't an all or nothing thing (static types suck), but an obstinate cultural attitude that's gone on for 15 years.
C# might not be as concise as some languages, but it shows you can have something a lot like Java that isn't as bad... and that makes it clear how outrageous Java is!
It's fair because there is nothing stopping you from picking up any of them, a decent framework and be orders of magnitude more productive than either a Java or a C# developer. C# is a better language than Java, but it still comes short when it comes to developing web applications.
There are hugely successful apps written in C# and Java, I agree, but their existence is owed more to the brilliance of their developers than a brilliant choice of tools.
Strikingly though one of the criticisms that seemed most poignant to me is:
"GWT completely ignores the fact you are creating a website, NOT an application"... I think this shows a serious lack of forethought on the author's part to not see that many websites were turning into web applications, and many enterprise applications with desktop clients had also started to go down this route.
Lately I've been reading a lot of blog posts assailing a technology as though proponents of that technology think all other tools are useless in all situations.
Replace "GWT" and "JS" in this article with "C++" and "Assembly," and all of the points still hold. But C++ is still incredibly useful for many developers, and so is GWT.
GWT largely exists because it has a reason to exist. One of its main reasons to exist is that browsers are not standards compliant, and sometimes the standards are ill-defined. A well-defined abstraction layer on top of that is very useful... right up until it's not. Sometimes you need to dig in to Assembly, and sometimes you need to dig in to JS. But quite often, higher-level abstractions get you all the way from start to finish.
... yeah, like when C gets compiled to machine code, you lose all the benefits of machine code.
On some level that's true. You can certainly write machine code that's faster than C, and often you can take advantage of hardware features that the C compiler can't use (in some cases, SIMD.) On the other hand, C code can be portable across platforms and developers can be more productive.
GWT keeps one important attribute of Javascript: the ability to run cross-platform on web-browsers. It trades the benefits of programming in Javascript for the benefits of programming in Java. Static types have some advantages, and you get to work with Eclipse and have automated refactoring and a good debugger.
His fundamental criticism against single-page webapps is valid, but this is true about Java applets, Flash, Silverlight as well as some Javascript frameworks.
A fundamental criticism I'd have of GWT is that it's very to build very complex applications in GWT, complex enough that the problem of managing asynchronous communication becomes a real bear.
You know that's an apples to oranges comparison. JavaScript and C are much more expressive than assembly language. This complain is that you are writing code in a less expressive language (Java) that's being compiled into a subset of a more expressive one (JavaScript).
Most of the features people like in Javascript can be faked in some manner in Java. Anonymous objects can be used to insert anonymous functions into Java code... At great cost in verbosity. Variables never really escape Java "closures" but the resulting immutability leads to a functional programming style that has real benefits.
Javascript's real advantage is a clearer syntax that's easier to learn and easier to read. If statically typed languages value concision, we can get the benefits of static types with little cost.
Sure, GWT does not create the cleanest mark-up and javascript in the world but maybe that is not always your goal. You may just want to get a web app up and running quickly but are lacking the javascript expertise - cue GWT, which allows you to harness your java expertise to create a web app.
If you don't like to create web apps this way (I for one would much prefer to hand code javascript), then don't but also don't go around name-calling the technology "disgraceful" just because it does not serve your own specific purposes.
I am not saying that GWT is perfect for everything, but it pains me to think of writing (and debugging, and refactoring) a large application in javascript, or any weakly typed language. I've tried it, and found it difficult to maintain.
