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I'm in the planning stage of a web application and I'm trying to choose between GWT and Cappuccino. I have an idea of which one I think is better, but my partner is sold on the other choice. I was hoping to get some feedback on pros and cons for each from people who have used one or the other or both. Thanks in advance for any insight you might have.
Toolkit v/s Framework
GWT is a toolkit. Its strength lies in the tools it provides to create an application. It doesn't provide a framework though. Developers usually build a small framework over GWT to suit their needs. There has been a lot of emphasis on MVP pattern to build apps, but it isn't the only way to use GWT.
Cappuccino is a Framework. It has a prescribed way of building applications. Additionally, it provides libraries to perform high level tasks like animation, drag-and-drop undo/redo etc. GWT doesn't provide any libraries for such tasks, though third party libraries are available.
This means that Cappuccino apps tend to be richer than corresponding GWT apps.
Offline Compilation v/s Runtime Translation
GWT believes in making decisions at compile time. Browser detection, I18N, image inlining, generation of sprites, uibinder template evaluation are all performed at compile time. Deferred Binding allows developers to leverage this concept in their own applications.
EDIT
Cappuccino, by default, does not need compilation. The browser downloads objective-j files, and then the framework translates/interprets them directly at runtime. However, it is possible to compile using jake. You can choose from several minifiers/compressors, including google's closure compiler.
As a result of this architectural decision, GWT apps tend to be faster at runtime than equivalent Cappuccino apps. However, because of the compile time cost, development tends to be slower than Cappuccino. GWT development plugin somewhat eases this pain, but the cost doesn't go away entirely.
Since GWT is a closed-world compiler, it can remove unused code, inline method calls, intern strings and optimize code in ways Cappuccino cannot. If Cappuccino were to introduce a compilation step, it could perform the same optimizations; but to the best of my knowledge there is no way to do the translation at compile time.
With the optional compilation step, this point becomes moot. However, cappuccino applications that do not perform such a compilation will have a poor performance as compared to a GWT app.
Type Safety
GWT is java - and is therefore type safe. Objective J is javascript, and therefore dynamically typed. This has its own advantages and disadvantages, and since it is a religious discussion, I will refrain from making a judgement.
Debugging
GWT provides a browser plugin that helps developers directly debug Java code. In development mode, developers get to see java stack traces. At runtime, however, the generated JS code is obfuscated, and very difficult to debug (though there is a way to tell GWT 'don't obfuscate my code').
Using the super-dev-mode it is now possible to debug the Java code directly from the web-browser.
Cappuccino doesn't have a development mode, which means you have to use existing tools like firebug to debug. Errors are reported by the browser, and to debug code you have to use JS debuggers.
Unit Testing
With GWT, you can write pure java unit test cases that do not require a browser to run. This has obvious advantages - speed and ability to reuse existing infrastructure are some of them. When you do need a browser to test, you can choose from GWTTestCase or HTMLUnit. Its also possible to test using Selenium.
Cappuccino apps can be tested using OJTest. Unfortunately, I couldn't find much documentation on the subject, so can't comment much. Of course, you can always use Selenium to test your webapp.
Interoperability with Javascript
GWT provides a way to talk to existing JS libraries - its called Javascript Native Interface. It is mature and works well, but isn't really intuitive. Objective J is javascript, so you don't have to do anything special to inter-operate with Javascript.
Vision
I can't back this argument, but GWT tends to focus on creating high-performance web applications without caring much about look and feel. They never compromise on performance. Cappuccino on the other hand tends to focus on higher level features and frameworks, and compromise on run time performance.
As a result, Cappuccino apps look richer, but take a while to load. GWT apps load and respond faster, but look boring. You can get around both the problems, I am sure - but that's the way it is out-of-the-box.
Community Support and Backing
GWT is backed by Google. Their commitment to GWT is pretty strong. Newer applications (Wave, Adwords, Orkut) from Google are built on GWT. Google IO has had several sessions on GWT. The user forum is pretty active and responsive, and the toolkit itself is actively developed and maintained by Google and the open source community. The Cappuccino user group isn't as active, and has far fewer members.
I am much more experienced with Cappuccino than GWT, but from the looks of it GWT looks blazingly fast and fairly robust. It is after all backed by a fairly large player in the internet field. The demonstration at Google IO was impressive. Although this might change, GWT apps totally leave Cappuccino in the dust when it comes to load times and deployment size today.
That said, I went with Cappuccino for two reasons: first, while GWT is a classical 'good enough' engineering solution, Cappuccino is squarely targeted at 'only the best is good enough' crowd. I believe that with Cappuccino you can achieve a standard rarely seen on the web before. Not only in pretty pixels, but in raw functionality and power where everything just works at a 'desktop quality' level. Drag and drop, undo stack, fluid scrolling and resizing, split panes, and on and on. GWT is catching up, as seen in Google Wave, but it has a long way to go and Google has not traditionally cared much about polish. This is visible, for instance, in Gmail which is still not only drab looking but clunky in the user interaction after this many years.
The second reason I went with Cappuccino is that Java drives me insane with its inflexible, ridiculously verbose and unreadable style. But that might only be me.
You might be interested in my new GWT UI Framework, CappuccinoGWT
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I am planning to write a web application. However, I want to write both the client and server side in Scala. Should I choose Scala.js? or should I go for GWT. What are the cases where I have to choose one over the other? Also, are there any other Scala frameworks that can be used for client web programming aside from the two?
None of those two should be used.
ScalaGWT has been abandonned for more than a year.
Scala.js is experimental and requires your users to download a 16Mo library (it will improve, but it is unacceptable except for some game apps).
[edit] the library has been downsized and this statement is no longer true at this time.
Other technologies are available, but choosing one depends of the kind of app you want to write. If you plan to develop a thin client, using a templating technology (like JSP or JSF), you could consider using Play templates, Lift, Scalatra, ...
To help you consider your needs, here is a few thoughts:
You'll need widgets and stuff to design your UI and those things are typically component-oriented and event-driven. In such a case FP doesn't offer much advantage over OOP.
In a standard enterprise application, scala.js would be useful to design a clean functional library for js code. This kind of library definitely has much to offer but it won't be the core of your client-side code. Instead widgets, MVC infrastructure, and a layer for integration with the back-end will be what you'll spend most of your time working on.
GWT has been around for a long time. I consider it a mature and proven technology. You'll have to learn a few tweaks and patterns to be able to fully exploit its potential, but in my opinion, much less than what is needed to write clean and maintainable js code.
GWT doesn't require you to know js at all (although we all agree it's always best to know a bit about what happens in the browser). You won't go far with scala.js if you don't know what you're compiling to.
If you already know javascript well, it's going to be easier to directly type your scala code as if it were some kind of scala-enabled js .
It's much easier for large teams to work with GWT than with js, as you can factor you code easily, favoring code testing and reuse at the same time.
GWT is definitely object(widget/model/view/controller)-oriented and event-driven. If you have plans to design an interface in a fully functional way (for games or very specific apps), I think it will get in the way of your design.
GWT
Mature
It's a full-fledged toolkit
GWT-specific patterns and good practices are well-documented
Easy integration with a java/scala back-end
Development scales well over big teams
Best if you don't know js yet
Object-oriented, GWT goodness is there (dependency injection, MVP, Async, i18n, JSR-303 validation ...)
Will optimize and compile your code to a small js file
Scala.js
Quite new, work-in-progress
Not a toolkit, but a compiler.
Hence you'll need to be aware about js good practices, design patterns and libraries, since your scala code will be interacting with js (quite) directly
Need to write/wire a layer for integration with the back-end yourself
Much harder to handle a big team
No need to know GWT :-)
Functional programming, Scala goodness is there (trait, patterns, case classes, ...)
[edit] At the time the question was asked, required a 16 Mo library
Final advice
Do you need widgets and complex interactions betweens UI components or is it enough for you to use a templating technology ?
Use ScalaGWT at your own risk.
You could use scala.js for js library design, experimental projects, games, ... You can call the js code compiled from scala.js from your GWT app (if you get past the 16 Mo library)
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I used play2 before with java. It felt a little bit like boilerplate especially if you used akka with java. But that is not the fault of the framework.
Yesterday I read "Scala for the impatient" and I really enjoy the language.
Now I looked at both frameworks Lift 2.5 and Play 2.0.3. I think lift has a higher learning curve and I could not just do something with lift. This is not a con for me. From what I saw, Lift has a very nice and clean design.
But for me it is hard to tell what the main differences are. I think both frameworks are great.
The Views First approach doesn't allow you to code in your templates, instead you have to code in snippets. I like this a lot because it looks more organized to me. It also lets you use a normal html editor.
(I have not much experience, this is just my first impression)
For the security I don't think that is the job of the framework.
Stateless/Stateful : It is hard to tell where the main differences are. I only know that play has also a state if you use web sockets.
Both frameworks are able to compile after you press F5. I like this feature a lot.
Both frameworks are using sbt
Lift comes with authorization but I think there is a play2 scala plugin that does the same thing
Lift has a ORM mapper for mongoDB. Because I want to use noSQL, this looks cleaner to me.(Again not much experience) Edit There is a ORM mapper for scala mongodb in play2 https://github.com/leon/play-salat
Async - Play 2 uses Akka. Don't know what lift uses but they also have something similar.
Lift ships with CSRF support. Play2 has a modul for CSRF but this adds a boilerplate to your code.
Stateless authentication seems to have some security vulnerabilities. Both frameworks have the stateful authentication. (play2 stateful/stateless , lift stateful)
What are the strengths of each framework?
Posting this after spending a week or two with Lift doesn't really
serve anybody's interests. However, I want to spend some time correcting
some mistakes and mis-perceptions.
For the security I don't think that is the job of the framework.
You're dead wrong. Security is the job of the framework. It's critical that security
is done by default rather than relying on each developer to understand every
security vulnerability and make sure every line of code takes that into account.
All we have to do is look at what happened to GitHub
to understand that even the best coders using well known technology
can make a critical mistake.
Lift gives a solid security layer on top, so by default, there's no XSS, CSRF, etc.
but the developer can dig down as deep as he wants to the HTTP request and deal
with the bytes on the wire.
Stateless/Stateful : It is hard to tell where the main differences are. I only know that play has also a state if you use web sockets.
Lift is very clear about where you need state and where you don't. Lift can support
stateless, partially stateful, and completely stateful apps. On a page-by-page and
request-by-request basis, a Lift app can be stateful or stateless (for example,
in Foursquare, the venue pages are stateless for
search engine crawls, but stateful for browsers that are logged in.) For
more on the design decisions around state, please see Lift, State, and Scaling.
Both frameworks are using sbt
Lift uses Maven, sbt, Buildr, and even Ant. Lift is agnostic about the build environment
and about the deploy environment (Java EE container, Netty, whatever). This is important
because it make Lift easier to integrate with the rest of your environment.
Lift comes with authorization but I think there is a play2 scala plugin that does the same thing
Lift has been around for 5+ years and has a lot of modules and stuff for it. The Lift web framework (as distinguished from the modules) is agnostic about persistence, authentication, etc., so you can use anything with Lift.
Async - Play 2 uses Akka. Don't know what lift uses but they also have something similar.
Lift has had Async support for more than 5 years. It's baked into the framework. Lift's Comet support is the best of any web framework because,
among other things, it multiplexes all the "push" requests on a page through a single request
to the server which avoids connection starvation. How Lift does async is a whole lot
less important because one of the core philosophies with Lift is that we remove the
plumbing from the developer so the developer can focus on business logic.
But for those who care, Lift has the best and lightest weight actors of any framework in
Scala-land. We were the first to break away from the Scala Actor's library and worked
to blaze the trail for different Actor libraries that allowed Akka and ScalaZ Actors
to flourish.
Lift ships with CSRF support. Play2 has a modul for CSRF but this adds a boilerplate to your code.
This is part of Lift's commitment to security. It's important.
Stateless authentication seems to have some security vulnerabilities. Both frameworks have the stateful authentication. (play2 stateful/stateless , lift stateful)
Lift apps can be as stateful or as stateless as you want. It's your choice and Lift
makes very clear how to make the decision.
Also, as I pointed out in the Lift, State, and Scaling post, making the developer figure out
how to serialize state in a secure, scalable, performant way
(because virtually every request on a web
app that recognizes specific users is stateful) should be done in a predictable,
secure way by the framework with reasonable overrides for the developers.
Parting note
Play is a lot like Rails: it's quick to get a site knocked together and it's
based on MVC, so a lot of developers understand it. But Play lacks the
depth and breadth of Rails (community, plugins, expertise, talent, etc.) If you
want quick, easy MVC, then go with Rails and JRuby and write your
back end in Scala (they work together extraordinarily well.)
Lift is a different beast. There's a significant unlearning curve (stop thinking
MVC and start thinking about user experience first that flows to business logic.)
But once you're up the unlearning curve, Lift sites are more secure, highly
scalable, super-interactive, and much easier to maintain over time.
To see what can be done with Play (it can be cool), have a look at the TypeSafe Console
To get going quick with Lift, use a template project.
For a sample of using Mongo with Play, look at Factile.
In summary, I don't think you will go wrong with either Lift or Play. Both are active projects, with good communities and good backing from the authors. It really depends on your business problem. If tool support are important to you, then you may want to look at using Play (it's well supported on IntelliJ Idea).
Take note that Play, being part of the TypeSafe technology stack, will have builds up to the latest versions of Scala, so if using Scala 2.10 features are important to you, then you may want to keep that in mind. Lift is currently using Scala 2.9.2, which is fine also.
For my current project I use lift-mapper for ORM (It's great and rock solid), with Spray for REST (which is simply amazing). This approach avoids frameworks altogether, but it depends on what you want to do. Frameworks are quite often the way to go.
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Closed 9 years ago.
My company is planning on developing a brand new web front-end application.
Some background:
It must "sizzle" i.e. a nice marketable look and feel.
Our development team has no Java experience, with limited experience in Silverlight, Javascript, JQuery or CSS.
Time to market is a factor.
We need to stream large amounts of data from an Oracle database.
It must support 500 - 1000 concurrent users
It will be hosted internally behind a firewall.
We need mapping (geo-spatial) capabilities.
Someone has recommended using GWT instead of Silverlight or Traditional technologies(Javascript, jquery, CSS etc.).
I am not sure if this is the right way to go? A lot of the GWT news is from 2007/2008. It makes me think that this technology is old and maybe dying.
If you had a choice would you choose GWT?
unfortunately two of your statements are mutually exclusive in this context:
Our development team has no Java experience
Time to market is a factor
I'm a Java programmer who has picked up GWT over the last year or so. It's immensely effective being able to write direct to the browser using a compiled language & mature development tools. I can fly through web-development faster than ever before (using ASP, JSP, ExtJS ...).
But, as the other commenters have said: if you've no Java experience you're going to find it a real challenge picking up both technologies (Java & GWT) in a short time. If you do manage to make it to market in a reasonable time I could only imagine the code base would be in very poor condition (since you'd be learning as you go) - which would be a very poor foundation for your organisation's shiny new venture.
There again, you don't have a 'lot' of skills in the other related skills you listed either.
I suspect there's a more effective solution. As some wise old goat project manager said:
I have three variables to delivering your project: time, cost and quality. Pick any two
In your situation, if the organisation wants a quality product in a short time, it's the cost factor that must compensate - your organisation should buy in some interim GWT expertise to give you a sound software architecture and to mentor your team for the next few months. After that you'll be ready to take the reigns, inheriting a quality codebase by 'standing on the shoulders of giants'.
As others have said, GWT definitely is not a dying project. Quite the contrary actually as there are now more than 20 regular contributors from within Google (versus a semi-dozen back in 2008). Wave (despite being discontinued as a Google service, it's still alive as an Apache Foundation project), Orkut, AdWords, Google Moderator and the new (still beta) Google Groups are made with GWT; and parts of Google Buzz and a few other projects at Google are built with it too.
Now as to your choice:
Silverlight is a dying technology. Microsoft made it clear that it now invests in "HTML5": http://www.zdnet.com/blog/microsoft/microsoft-our-strategy-with-silverlight-has-shifted/7834
GWT is mostly a client-side toolkit, but it comes with "high productivity" tools for client-server communications (GWT-RPC and RequestFactory for end-to-end protocols, AutoBeans for easy JSON serialization). With UiBinder, you can easily put to use your web designer skills.
if you're comfortable with JS, then go for it, but then you'd have to choose the "right toolkit" (jQuery? Google Closure?). Otherwise (which seems to be the case), it really depends how much "ajaxy" you need/want to be. I'm a strong believer in "one-page apps", but YMMV, or you can have specific constraints that rule it out. In any case, you'd have to choose a server-side technology.
So, depending on your needs/wants and skills, I'd choose GWT or "some JS toolkit". In any case, you'll have full control over the look and feel (unless you choose one of the bloated players: ExtJS/ExtGWT, SmartGWT or similar; you'll probably have a shorter time-to-market with these, but you'll pay it later, in terms of performance, integration with other toolkits, and look-and-feel).
In the light of what you're saying about your skills, I would definitely recommend GWT (despite your lack of experience with Java); because lack of experience with JavaScript is far worse than lack of experience with Java (you're talking about a "large application", so it's really important to start building things right and/or have tools to help refactoring, which you'll have with Java).
#ianmayo replied while I was writing the above, and I can only second what he said!
GWT is definitely not old or dying! A lot of Google's own applications are developed using GWT. You can download the GBST case study and learn how the global financial company uses GWT to improve productivity and create a rich user experience. You have to know that when you use GWT you automatically use javascript, html, etc. You create a your gwt application in java, but when you compile it gwt creates a folder with html files, javascript code, css, etc...
I definitely recommend it!
In order not to mislead readers with above seemingly unanimous answers, keep objective view in respected stackoverflow, following review expressed exact experiences I had with using GWT. Whether GWT is dying depends on how many new apps will adopt it,Google trend can tell (gwt trend).
Excerpt from https://softwareengineering.stackexchange.com/questions/38441/when-not-to-use-google-web-toolkit
>
I am both good and bad to answer this question - good, in that I've actually used it before, and bad, in that I was quite experienced with HTML/CSS/JavaScript prior to working with GWT. This left me maddened by using GWT in a way that other Java developers who don't really know DHTML may not have been.
GWT does what it says - it abstracts JavaScript and to some degree HTML into Java. To many developers, this sounds brilliant. However, we know, as Jeff Atwood puts it, all abstractions are failed abstractions (worth a read if considering GWT). With GWT, this specifically introduces the following problems:
Using HTML in GWT sucks.
As I said it, to some degree, even abstracts away HTML. It sounds good to a Java developer. But it's not. HTML is a document markup format. If you wanted to create Java objects to define a document, you would not use document markup elements. It is maddeningly verbose. It is also not controlled enough. In HTML there is essentially one way to write
<p>Hello how are <b>you</b>?</p>
In GWT, you have 3 child nodes (text, B, text) attached to a P node. You can either create the P first, or create the child nodes first. One of the child nodes might be the return result of a function. After a few months of development with many developers, trying to decipher what your HTML document looks like by tracing your GWT code is a headache-inducing process.
In the end, the team decided that maybe using HTMLPanel for all HTML was the right way to go. Now, you've lost many of GWT's advantages of having elements readily available to Java code to bind easily for data.
Using CSS in GWT sucks.
By attachment to HTML abstraction, this means that the way you have to use CSS is also different. It might have improved since I last used GWT (about 9 months ago), but at the time, CSS support was a mess. Because of the way GWT makes you create HTML, you often have levels of nodes that you didn't know were injected (any CSS dev knows how this can dramatically affect rendering). There were too many ways to embed or link CSS, resulting in a confusing mess of namespaces. On top of that you had the sprite support, which again sounds nice, but actually mutated your CSS and we had problems with it writing properties which we then had to explicitly overwrite later, or in some cases, thwarted our attempts to match our hand-coded CSS and having to just redesign it in ways that GWT didn't screw it up.
Union of problems, intersection of benefits
Any languages is going to have it's own set of problems and benefits. Whether you use it is a weighted formula based on those. When you have an abstraction, what you get is a union of all the problems, and an intersection of the benefits. JavaScript has it's problems, and is commonly derided among server-side engineers, but it also has quite a few features that are helpful for rapid web development. Think closures, syntax shorthand, ad-hoc objects, all of the stuff done by Jquery (like DOM querying by CSS selector). Now forget about using it in GWT!
Separation of concerns
We all know that as the size of a project grows, having good separation of concerns is critical. One of the most important is the separation between display and processing. GWT made this really hard. Probably not impossible, but the team I was on never came up with a good solution, and even when we thought we had, we always had one leaking into the other.
Desktop != Web
As #Berin Loritsch posted in the comments, the model or mindset GWT is built for is living applications, where a program has a living display tightly coupled with a processing engine. This sounds good because that's what so many feel the web is lacking. But there are two problems: A) The web is built on HTTP and this is inherently different. As I mentioned above, the technologies built on HTTP - HTML, CSS, even resource-loading and caching (images, etc.), have been built for that platform. B) Java developers who have been working on the web do not easily switch to this desktop-application mindset. Architecture in this world is an entirely different discipline. Flex developers would probably be more suited to GWT than Java web developers.
In conclusion...
GWT is capable of producing quick-and-dirty AJAX applications quite easily using just Java. If quick-and-dirty doesn't sound like what you want, don't use it. The company I was working for was a company that cared a lot about the end product, and it's sense of polish, both visual and interactive, to the user. For us front-end developers, this meant that we needed to control HTML, CSS, and JavaScript in ways that made using GWT like trying to play the piano with boxing gloves on
First of all , GWT is not dying technology, its usage increases, and its latest version is 2.2. I am using GWT for 2 years, since version 1.6. Its improvements since them is quite amazing.
Since GWT is client side technology, it does have only positive effects of your application scaliblity feature. Because server side web technologies such as jsf, struts, wicket are server resource consumers, but gwt does not need any server resource to render user interface..
But there is problem for your team. Because your team has no java experience, it would be quite difficult to adapt yourself two new technologies java and gwt.. If you have time to learn , I would strongly suggest GWT.
It takes approx 1 year to become proficient in GWT. Using GWT pays off if you develop an application as sophisticated as MicrosoftOffice or PhotoShop. It makes no sense to use GWT for small and relatively simple apps, IMHO. GWT is a time killing framework indeed, and you have to have very strong reasons to use it. I think that 99% of web apps don't need GWT.
GWT is not dying framework, but time killing framework. It has security issue. You can do easily CSRF(Cross site request forgery) request to the GWT applications. Also Java and Javascript are totally different languages, you can't translate easily. For your productivity avoid GWT.
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From the following list of frameworks, which one would you use to develop a rich web application and why would you choose it over the others?
Sproutcore
GWT
ExtJS
GXT
SmartGWT
Dojo / Dijit
Flex
Capuccino
Grails
I'm personally tired of browser inconsistencies. If someone else has solved the problem, I'd rather not do it again. That's why I'm getting more interested in front ends like cappuccino and qooxdoo. They are a zero-HTML zero-CSS solution.
These are based on my personal experiences using the frameworks you have mentioned. So yes, it is a bit biased. So as others have said over and over again, define your requirements and which one do you think fits your requirement based on what people have suggested here.
GWT is too verbose eventhough I found many Java developers love GWT because you can unit test it and it's all in Java. But I personally don't like it because it is far from being simple. There are times when I feel I can tweak a little bit with Javascript, but with GWT I am enforced to do it with several lines of Java code.
GXT is too far from GWT these days and you will find it difficult to do things as GXT has its own way of doing things which is way too different from GWT. When complex requirement come up, in the end you are going to go back doing plain GWT. And oh, their technical support is not that good either as I had several bad experiences when asking few questions to them.
Ext-JS is good for simple stuff and the look and feel is really slick. But when things gets more complex, you are going to fight you're way through. Eventhough I have dealt with the GXT tech support, I haven't dealt with the ExtJS tech support since they have different people eventhough it's in one company, so I can't say much.
Flex is nice, really nice. But again it is good for simple stuff. Once things gets more complicated you are going to write lots of actionscript, which is less enjoyable. There are many things that is available out of the box which may be to difficult if you have to code it in Javascript, like multimedia support. And oh, if you are writing for a public website you must consider that not too many user has flash plugin on their browser.
Grails, I'm not sure how you would implement RIA apps with Grails since Grails is just another MVC framework which you need to add your own RIA framework on top of it such as the ones that you have mentioned.
This is strictly a matter of opinion. You will not get any definitive answers from anyone, since anyone that answers will have one or another that they personally prefer.
Try each one for long enough to decide which one is best for your (or your team's) purposes.
That being said, I prefer GWT. Others will invariably disagree with me.
Reasons that I like GWT:
You can share (some) client- and server-side code (as long as your server is written in Java)
GWT makes a lot of advanced performance features really easy (e.g., deferred JS loading, image spriting, CSS obfuscation)
A focus on one-page apps, with third-party support for Places (using the gwt-presenter library)
It's just as easy to add GWT to an existing web page as it is to create a full one-page GWT app
UiBinder allows you to write your UI using a declarative HTML-like syntax; you're not stuck writing Swing-like UI if you don't want to
Browser incompatibilities are (mostly) taken care of by GWT -- you just write Java code, and GWT compiles it to work on every browser
Things that may make GWT not right for you:
If your server is already written in something besides Java, you will still be able to write your UI in GWT, but you'll lose out on some nice features
Compilation time using GWT is a non-trivial cost -- Development Mode mitigates this a lot, but it's still an issue sometimes
As others have mentioned, GWT can be considered "verbose" compared to simple JavaScript libraries like jQuery or ExtJS
Ext GWT has worked well for my project. The premium support has been good.
However the project is for internal use which has allowed deployment to be restricted to one browser on one OS, and no effort has been made to change the default appearance or behaviour of Ext GWT.
Developing entirely within Java is a key benefit as it helps to keep the project manageable as features are added.
I am currently working on a grail/flex hybrid app that is working a lot better than I expected. I have looked at GWT but there were not a lot of books about it at the time and it seemed to stress the leveraging of Swing-like programming techniques which I have never liked. I agree with the comment about trying them all out. Run hello app they all have and measure how hard or easy it is to modify. Also tool (IDEs, Maven, CI...etc) support can be a big factor as well in terms of being immediately productive.
We are using Grails+ExtJS here. Since we try to make an idiomatic ExtJS application, Grails is not fully utilized, though it still makes sense to use Grails instead of, say, JSP, for the server-side part.
Why ExtJS: Because it's a very rich toolkit for GUI-like web applications. Our job is to replace an old Motif GUI, so this is exactly what we need.
Why Grails: Because it gets the job done easily and quickly. For the communication with the ExtJS part, we need a lot of JSON, and in Grails it's like that:
import foo.bar.FooBar
class FooBarController {
def viewFooBars = {
def list = FooBar.getList(session.userId, params.foo, params.bar)
def result = [resultset: list] as JSON
response.setHeader('Content-disposition', 'filename="json"')
response.contentType = "text/json";
render result
}
}
And that's even two or three lines more than necessary...
Unfortunately the answer will be opinionated, GWT in it's purest form is not an eye-candy. That being said, ExtJs GXT is super hunky dory. One of the major issues I face with evolving frameworks is that they are not absolutely defect free, If I remember correctly, GWT 2.0 was shipped out with missing CSS styles for some of the new layouts. I am trying to trouble shoot an issue in ExtJs/GXT since last 5 days :(, frameworks obfuscate a lot of things. I will go with any framework that is absolutely robust and gives appropriate error messages. I haven't worked with others though.
I'd recommend Dojo.
In addition to the massive infrastructure it provides, Dojo 1.6 is also the first (and only) popular JavaScript Library that can be successfully used with the Closure Compiler's Advanced mode, with all the size, performance and obfuscation benefits attached to it -- other than Google's own Closure Library, that is.
http://dojo-toolkit.33424.n3.nabble.com/file/n2636749/Using_the_Dojo_Toolkit_with_the_Closure_Compiler.pdf?by-user=t
In other words, a program using Dojo can be 100% obfuscated -- even the library itself.
Compiled code has exactly the same behavior as plain-text code, except that it is much smaller (average 25% over minifiers), runs much faster (especially on mobile devices), and almost impossible to reverse-engineer, even after passing through a beautifier, because the entire code base (including the library) is obfuscated.
Code that is only "minified" (e.g. YUI compressor, Uglify) can be easily reverse-engineered after passing through a beautifier.
ExtJs is great for creating complex web applications. The API provides anything you can imagine in a webapp and its really easy to extend any component after some time.
You can plug it to any backend (we use django or php) and reuse or extend any component in several different applications.
You'll need severals months to feel comfortable with it. IMHO.
That said, the lib is sometimes a bit too slow for simples uis like a website (then you can use ExtCore). But when it comes to webapps this is not an issue.
Im not a java guy so GWT was not an option for me :/
hope this helps
By day, I am a front-end web developer but in my off time I dabble with other languages such as C, Objective-C, Python, etc. When I first got into web development the idea of web applications was just getting started.
Since then two amazing frameworks have appeared, SproutIt's SproutCore and 280 North's Cappuccino (+Objective-J). SproutCore is being used by Apple for it's MobileMe application and 280 North released 280 Slides. Both of these applications are amazing and they are a testament to what is possible on the web. So the momentum is shifting. Web applications starting to look and act like desktop applications.
So my question is this: should web based applications follow web standards, separation of markup (content), presentation (design), and behavior (functionality) or no?
I am not sure about SproutCore since I have not look at the source code, but I know that if you go to 280slides.com and turn off the JavaScript everything basically disappears. You are left with some meaningless words.
Let me clarify, I understand that web based applications such as 280 Slides is meant to have JavaScript on and not meant to be functional without it but in my day job my main focus is writing clean markup, separating content, presentation, and behavior so that our site and applications can be used by as many people as possible.
It seems like the other people who have answered so far have no idea what you're talking about.
Like me, you've had it pounded into your head to make your web applications as accessible as possible. That is, they should work without scripting and without stylesheets. JavaScript and CSS should only be used to enhance the experience. They should not be required.
SproutCore and Cappuccino are frameworks for front-end development that require the user to have both JavaScript and CSS enabled. Your question is around how we reconcile this with the dogma of the day.
Unfortunately, I don't have a clear-cut answer. I like the fact that SproutCore and Cappuccino (and probably others) are testing the limits of what's possible within a web browser. I also believe firmly that information and services provided on the web should be available to as many people as possible, given the limitations of the technology.
How you approach your solutions needs to be based on a deep knowledge of your user-base. If you're working on an iPhone app, you don't need to worry about traditional web accessibility because the experience is intensely visual. If you're building a web application for a general audience, these new frameworks are probably a poor choice (if you value the widest possible access to your information and services).
Over time, screen reader software is likely to get better at interpreting JavaScript-heavy interfaces, so perhaps this issue will fade. Thing is, something else is likely to "sprout" up in its place.
Javascript is a Web standard — certainly more so than, say, Flash, which was previously (and still often is) used for rich Web applications. In this regard, SproutCore and Cappuccino are giant improvements in my book.
The question here really seems to be how important accessibility is. And that is largely a personal decision based, as Andrew said, on knowing your users. For some apps, accessibility really doesn't make that much sense — 280 Slides is a good example of this. It's a graphic design app that's largely about visual behaviors. It doesn't make very much sense for it to degrade to plaintext. (At least, a text-based app meant to accomplish what 280 Slides does would be really be a completely different thing.)
Yes. It will be difficult at first, but once the codebase matures you will be thankful you followed those rigorous standards.
Edit: An added benefit will be portability to many web-based platform via CSS profiles and whatnot.
The MVC model can be applied just as easily to desktop applications as it can to web based applications. I don't see much reason to distinguish between the two, especially since the line is more blurred in the case of web applications.
I don't know about these particular frameworks, but a lot of web frameworks these days are structured around the MVC model, such as ASP MVC, CakePHP, Ruby on Rails, etc.
Separate as much as you can and it will pay out in the end. When things get complicated and hairy :)
I think they should. Following that type of MVC design allows for changes to be more easily implemented, provides good separation of concern, and is generally easier to understand for newcomers to a project.