The strategy about how to use the GWT and PlayFramework together - gwt

Does it make sense to use Play just for making the main layout, and use GWT-compoments (like # {some_gwt_component}) if it's needed (for example to implelemnt this component with jquery/javascript/html is quite complicated)?
Why I'm asking, because, it seems, some thinks easy to implement just with html some with gwt.

I can't think that it's a good idea to mix this techniques. Has you seen the post on google-groups? It refers to information about play and gwt.

I wouldn't recomend it, GWT relies in the Servlet model (as far as I remember, I may be wrong) and that doesn't mix well with Play.
Also, on a more personal level, I know GWT is not really recommended by Thoughtworks as a technology (they list several issues with it) and given the technological knowledge of those guys, I usually trust their recommendations. Stay away from GWT :)

Related

Best suite for GWT widgets

I am looking to build a GWT based web application. Being new to GWT, am looking for suites that provide the best GWT widgets (in terms of user experience, variety, styles, etc.), to help build a web app.
I have come across SmartGWT, but looking for other options/suggestions.
Thanks in advance!
I've done apps in both GWT and SmartGWT. My observations, for what it's worth:
SmartGWT has all sorts of cool features, out of the box. It's easy to be seduced by the SmartGWT showcase.
GWT is converging on SmartGWT, and quickly. For instance, the new DataGrid
can stand up against the SmartGWT ListGrid and come away looking good.
In order for GWT to look good though, there has to be real skill in the
developer. SmartGWT can make anyone look good, it seems, but to make
GWT shine takes skill.
Once you have that level of skill, though, there's no looking back.
GWT seems to me to be much more flexible, a consequence of the building-block approach. SmartGWT is more monolithic.
SmartGWT's design has some portability issues. I successfully took a pure GWT app I made and re-worked it (minimal effort) to run nicely in a BlackBerry PlayBook browser. I took a
SmartGWT app I had made at about the same time, and half the widgets
didn't work.
For an enterprise level solution I'm working on, I'm using pure GWT and I don't regret having made that choice.
I would suggest using standard gwt widgets. Simply because,
1)they are best documented,
2)they are highly customizable via css
3)from what I observe they provide the best performance
4)you dont need to learn a whole new framework built on top of another framework
but if you insist on using a framework then I suggest you take a look at this question
My advice to you is to consider your needs. Plain GWT and SmartGWT both are the best supported, so you need not look for more (unless of course both fail in what you want).
Go to their respective showcases and see what they offer and how it fits your requirements.
If gwt satisfies all your UI requirements, my advice is to choose it over SmartGWT. gwt beats SmartGWT in learning curve and documentation anytime. Also its faster(my opinion). If gwt doesn't satisfy your needs and SmartGWT does, then you should consider making the switch.
I have a year experience in smartGWT, when we started our first gwt lessons, they said use the basic gwt features and build own framework otherwise we can encounter errors which may lead to dead-ends. We considered the idea, but for the project (since we already had deadline) decided to look after some extension of gwt. We found smartGWT. The showcase was really convincing. Remember these are widgets, the basic logic of your system is still up to you.
In case if you start using smartGWT: If you don't use JSON but some normal list of java structures prepare to get hard hours/days to get use to datasources, grids, and few other components. Seriously, it had ridiculous problems (for example switching two configuration code line without reason makes work the listgrid), BUT before you drop the entire idea to use it, after a while it starts to work, and it becomes really impressive and comfortable. This is a kind of work "make it once, will work hundreds of times".
In my opinion:
don't start use smartGWT if you want to make a system which is not too complicated.
start use it if you need complicated system with lot of different features, if you don't have the time to develop everything for yourself: many components are ready in smartGWT.

What do I need to learn before I can start using Lift?

I know Scala. I've used mongoDB, redis, sbt, ... backend stuff.
I know basic HTML, CSS and JavaScript but have never done real web development.
I don't know what AJAX is. I don't really know any frontend stuff.
What should I learn before I start trying to tackle Lift?
If you know Scala, you are pretty much set on the programming side.
On the other hand, Lift requires HTML/CSS templates. In fact, it is completely separate from programming, so that a professional web designer can work on them, while the programmer works on the code. If you can revise your HTML/CSS stuff, it will help.
You don't need to know AJAX -- that part Lift takes care of for you.
So, it seems you are mostly set. I strongly recommend Timothy Perret's Lift in Action, from Manning. Though the book hasn't been released yet, you can get the Manning Early Access Program (MEAP) for it and, as it happens, the whole book has been written already.
If you already know Scala, learn some basics of web development and how Java handles it:
HTTP protocol
Servlets (also know what JSP is)
AJAX

Realizing the design from a design professional in code

I typically work on web apps that will only be used by a small group of well-controlled people, but now find that I'm writing something that has the potential to be used by a very large population. This means that the design and "look" will be very important to the success.
While I can certainly code up something functional, it ain't gonna look pretty, so I know that I'll need to get an outside designer to make things look good. Never having worked that way before I had a few questions about the mechanics of how this happens and how to try to make things easier.
We do Java, so when building a rich interface, we use GWT. I know that when working with designers, they typically provide images of what the interface should look like without any type of "useable" output. My question is how best to bridge that gap between a simple drawing of an interface to a fully functional realized one.
Any thoughts are appreciated.
Well, "it depends", as always.
Nowadays, I don't think you can work wit someone who simply provides PhotoShop mockups. At least not at your level. Mockups are simply too static, and translating those mockups to actual pages that actually work with different browsers properly is a skill set all its own.
So, you need someone beyond simply a designer, especially if you are planning any javascript wizardry, animations, or other dynamic elements that don't capture at all well on a static image.
What you really want is an "operational" mockup. Static HTML files that look and behave as best as can be done to what the UI designer wants to do, including transitions, work flow, etc. This artifact can be run through all of the stake holders as a live mockup, letting folks "Feel" the site.
Once you have these HTML files, you can then do your part of backfilling these pages with actual server side content. Obviously you can start early working on models and working with the designers so as to have services ready to support the site functionality, but you shouldn't be committing any real time in to actual pages for the site.
As for interacting with the designers, I talk more about that over here: How can I make my JSP project easier for a designer to work with
I worked on a project very much like this. We had "comps" which were pictures of what the interface would look like. We identified common objects and build modules. Then built pages (this was for a web app) from modules plus any elements that were unique to that "comp".
A couple things to keep in mind that will make life much easier: use the comps/drawings as more of a recommendation rather than set in stone design. Try to identify common pieces early on and reuse code.
Also, designers aren't user experience gods. They often have a good idea of how things should work, but if you are close to your product and have a lot of product knowledge, don't be afraid to tweak the design as you and your group see fit. One thing that designers typically lack is product knowledge. They know a lot about general user experience and how a site should work, but they often won't know the in's and out's of your use cases and products.
If you are working with GWT, you should look for designers who are expert in CSS. Apart from, may be, the main layout of the website, all the application components like form fields, dialogs, tabs and grids etc. will need to be styled using CSS.
If the designers are not experienced in working with GWT, share the GWT's documentation about styling with them. It's a good idea to read these yourself as well. Specifically explore the GWT's theme-ing system.
Also try to make use of UiBinder as much as possible. This would allow you to stay as close to traditional HTML based design while still enjoying the GWT high level object oriented interfaces (both widgets and DOM).
Optionally you might want to tell the designers that GWT image bundles will automatically do "CSS Sprites" so they don't need to worry about page load performance issues related to images.

Scala RIA with Lift and

I'm curious what's the "best" way to program RIAs with Scala.
I'm new to Scala and would simply like to know where to start learning. It seems obvious that for web-apps Lift is the perfect choice to be combined with Scala. However from what I've seen so far Lift is not really providing the key to great visuals. Certainly there are hundreds of possible frameworks due to the compability with Java but that's not very helpful.
What would you recommend ?
What is a common set-up ?
Among others I found cappuccino, a very impressive framework.
http://www.scala-lang.org/node/7281
It just seems like Cappuccino is designed for a language named Objective-J. That doesn't sound like great compability to me. Yet somehow they can work together.
http://frothy.liftweb.net/
Well, if you are new to Scala you should probably try Play, because learning a web framework and a new programming language is hard.
Play has a big community and seems to be quite user-friendly (pressing F5 in your browser reloads your code and displays any errors which have occured).
Normally any Java web framework can also be used in Scala, but Play seems to be pretty Scala-friendly.
There are quite a few Scala-specific web frameworks too, but I don't know enough to tell you more about them.
Lift is an powerful and impressive framework, but certainly nothing for beginners.
(I assume "new to Scala" doesn't mean "I programmed in Haskell, ML and Scheme for decades").
Of course it all depends. Personally, I have had no problem starting with Lift even though I’d only used Scala in the REPL before and just for some toying around to get to know the syntax.
It certainly helps a lot if you already know how to use collections in a functional way without explicit loops, so you can read and understand other people’s code more easily. But basically, I’d say it is doable learning both Lift and Scala at the same time even without a background in functional languages. It’s just the collections thing you’ll have to get used to and if you happen to know Ruby (or a language with list comprehensions) you’ll easily understand it.
The Frothy integration has not yet been updated to the newest version of Lift and I don’t know of any site which actually uses it but maybe this is a thing to ask on the Lift mailing list. In any case, I think Frothy only helps you connecting a Lift setup with some Cappuccino frontend but does not provide many wrappers to the Objective-J code, so you’ll still have to write code in Objective-J.
At that point you can ask yourself: Why not write the whole thing with Cappuccino and decide afterwards if Lift integration is actually needed.
Considering Lift alone: You certainly can use Lift with some UI Kit like JQuery UI for the visuals. Lift has many advanced possibilities which make it possible to build complicated web applications but you’ll have to care about the wiring for the visuals yourself.
(And arguably, a stateful, non-MVC (‘view first’) framework like Lift might be better suited for a rich internet application than a pure MVC framework…)

Which web application framework? [closed]

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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