I have a django-based web application that is a mixture of jQuery and several other JavaScript libraries. It has been suggested that consolidating everything under Google Web Toolkit would make moving things forward a little easier. So I have a few questions regarding this:
Could we keep our HTML/CSS or would we have to rewrite?
Would GWT integrate easily with JavaScript libraries that we already use? (datejs, jQuery.scrollTo, etc)
Would you recommend rewriting everything due to GWT's different workflow?
First, a caveat: there are different degrees to which you can "consolidate everything under Google Web Toolkit." You could just write a client-side JavaScript library in GWT, or write the entire client-side implementation in GWT, or write the client and the server in Java using GWT. I'll try to answer each of your questions for each of the use cases.
Could we keep our HTML/CSS or would we have to rewrite?
If you're just writing a client-side library in GWT, you could keep the HTML/CSS mostly intact. If you're writing the entire front-end or if you're writing the client and the server in GWT, you could probably port most of the HTML and CSS, but you would have to make a lot of little changes.
Would GWT integrate easily with JavaScript libraries that we already use? (datejs, jQuery.scrollTo, etc)
For the most part, yes.
If you're just writing a client-side library, then absolutely yes (because the GWT code would be just another library). If you're writing the entire front-end or the client and server in GWT, life will be harder because you'll probably have to write JSNI wrappers, which will take a little work but not be terrible.
Would you recommend rewriting everything due to GWT's different workflow?
No, I wouldn't. This isn't so much because of opinions on GWT versus JavaScript, but more because a total rewrite is usually a bad idea. A bunch of refactoring over time is a good idea, but throwing away code wholesale is usually a bad idea, because that code has been tested. If you throw away a bunch of code rather than refactoring over time, you lose bugfixes that you have made over time, and you make the same mistakes, test for them, find them, and fix them all over again.
Related
I have an enterprise Java web application deployed in tomcat.
I am looking for ways to integrate a HTML & JS UI with the mid tier java code. So far, from looking around I have read that there are two ways to do this which fit my requirements :
1) DWR - Direct web remoting
2) Use REST web services.
I am not sure which approach to use.
Edit: What is the advantage of using DWR over a rest WS design?
Is there a better approach available? Some people asked me to have a look at GWT, but I am not sure if these are scalable.
Edit 2: I will most likely be using dojo for the UI development(Works well with REST/DWR??), and I want to keep the java code chages minimal. I understand that by using web services, I would have to write an additional WS client layer on top of the existing java code.
Also, the usual enterprise needs, performance, scalability, etc.
Ok so you're building a web client frontend to your java backend, there are a few ways to go about this:
You want to use java standards as much as possible, preferably living in the java EE world: JSF. You will need some knowledge of HTML, XML and perhaps even javascript (though limited). Personally I have had a pretty buggy experience with JSF+richfaces to the extent that I don't use it anymore.
You are very well acquainted with java desktop application development but don't know much about javascript: vaadin: it allows you to write plain java using desktop application terminology which will be compiled to javascript. Currently I am working on a big vaadin project and it is very nice to be working with pure java in eclipse, the downside is however that you are far removed from the actual frontend, so tweaking can be tricky. Additionally everything is stored in sessions (afaik) and scales poorly.
You are primarily a frontend person with unrivaled javascript skills: use a REST interface in java and a pure js/html/css frontend. Personally I think this is the cleanest design and I have designed a few of my own applications like this. The downside is that managing large javascript projects tends to be hard because...well...javascript sucks. The upside is that this will always be the fastest most lightweight option available to you.
Ideologically I would definitely suggest the last approach but this can be hard for large projects. If you have the hardware to throw at it, vaadin is a nice option. My JSF 2 experience was a bit disappointing due to the bugs in (necessary) third party libraries like richfaces.
PS: I have never heard of DWR but the last stable release seems 2 years old and all it seems to do is expose java code as javascript methods which can be better handled with a REST interface.
Open interface standards like REST and SOAP make it easy to build code to consume these services if you are using frameworks to build a REST Client and a SOAP client code respectively. But the point is that you need to have this client code to make calls to these services.
DWR on the other hand, generates this client code. Your java classes are ready to be called (like you would do in Java).
Introduction
I am basically coming from two sides of the development teams. I started building web applications using PHP. This way, I had to implement everything by hand. Forms, graphical elements, how everything is tied together (i.e. what happens when you click a button).
On the other hand, some time ago I entered the Java Web world, namely JSF. Which is in my opinion a nice way to build a "serious" applications. (why I think so, read below)
Problem
I would like to build a web app that is made of a nice and useable frontend that is designed after my specifications (basically doing the HTML and graphical layout as a horizontal prototype first - as far as possible -, then make a complete webapp out of it). But on the other hand I would like to do all the business logic in Java because of its many nice frameworks out there - Hibernate, Morphia, Lombok, Dozer, just to name a few I met and fell in love with.
I could build the frontend with JSF myself but I still think, that I'm too limited because I have to use the built-in components that can only be customized to a certain amount. What if I want to use my own design patterns and UI elements and behavior but still want them to work together with a Java "backend"?
What would be the "best" choice of tools to achieve my goal? Choose a different web framework like Wicket or similar?
My idea: Build a web application in Java that understands the good old GET commands and translates it to the Java methods. Sort of a RESTful service - although I'm not a great fan of making everything RESTful in the frontend - unless you tell me, that's fine and reliable.
Have you considered / looked at Google Web Toolkit for what you're trying to craft?
GWT is Java behind the scenes yet still can get you where you want to go, if I understand what you're asking.
Just an update:
If GWT isn't your thing, take a look at the Groovy / Grails route.
Just some elaboration here based on a comment...
With Groovy/Grails you don't actually have to merge your front and back end. I have seen that done, but its not necessarily always 100% required.
For example, you could create a web app in Grails where your AJAX functions could be formed and stored with the UI code being delivered out to the client for Great-UI-Justice. For added fun, you can even instruct Grails to include a JS framework such as jQuery to help you out with the UI.
Now on the back end, you should be able to take your Java back end and apply it directly with little to no change. However, I would recommend looking into adjusting anything you've done so far to take advantage of the Grails methodology.
There are many JSF libraries like ICEfaces,
RICHfaces etc, that make use of things like AJAX, etc.
In my personal opinion it's always a good idea to have a RESTful API and treat your web page just like any other client ;)
I'm working on a client-side Java application for which I want to create a web-based user interface (which will be served up to a browser from the local app). At the risk of oversimplifying, its a microblogging tool that will support functionality similar to Twitter and Facebook. Its open source, and you can read more on our wiki.
Its important that this app is extremely easy to use, and I also want it to look good relative to contemporary web applications (such as the examples available on the Chrome web store). Since I am not a web designer, I'm hoping to use tools that give me an attractive UI "out of the box". Oh, and I need to keep the distributable file reasonably small (un him so whatever I use needs to be reasonably lightweight.
So far, I've looked at Sproutcore and GWT.
Sproutcore apps definite have the appearance I'm hoping for, but I'm not that familiar with JavaScript, and after some experimentation is not entirely clear to me how I will achieve some of the more sophisticated functionality that I think I'm going to need.
Being Java, GWT is more within my comfort zone, however I had a hell of a time just getting my development environment set up properly. It seems that GWT wants to dictate the structure of my application, but since the user interface is only a small part of it I'm not willing to build the entire app around GWT.
Something else I've been thinking about is using CoffeeScript (which seems more palatable him and him him him him him than JavaScript, and there are Maven builders for it), perhaps together with JQuery-UI.
What other options should I consider?
To recommend two big javascript frameworks Sencha and Cappuccino.
These have an extensive UI toolkit out of the box. The latter has an MVC framework build in, the former has a general JavaScript library build in. Both come highly recommended.
Also as recommended jQuery UI is a reasonable toolkit. I would personally couple Sencha for its rich UI toolkit and a lightweight MVC framework like Backbone. I'm afraid this does require learning JavaScript well.
You can also instead drive your JavaScript UI toolkit mainly from the server and skip the clientside MVC. For that sencha should surfice as a UI toolkit, but if you want meaningful functionality you will need some more structure. I would also recommend RequireJS for modular file management.
Take a look on Vaadin its based on GWT but simpler to use. I use it since 2 years and i'am not a designer too.
Take a look at jQuery & jQuery UI (jQuery Modile if you are looking to deploy to hand held devices)
Also, since you mentioned that you are not a designer, you might want to implement the front end in an MVVM pattern to separate the UI from the business logic of your applications. Knockout is a nice way to do with with decelerative data binding
I don't like writing plain JavaScript, so I'll tell you little bit about Java based frameworks. Recently, I've picked Google Web Toolkit.
Pros:
plenty of materials
Eclipse + Google plugin
Very intuitive API
3rd party libraries
Fancy widgets + optimized JavaScript
lot of generics
very active community
awesome async callbacks
Cons:
very slow debugging, that will drive you mad sooner or later
lot of deprecated code for so young framework
Mixed feelings:
You don't have to write declarative UI (you can do Swing-like development), but your code grows bigger and less maintainable, so it is quite probable that you'll eventually learn some declarative UI like UI Binder
Visual designer for GWT is somehow nice, but very unstable (eclipse) :(
Some considerations:
Do some prototyping with Vaadin. Try some debugging. Then try GWT and debugging on similar sized project. Consider debugging as the VERY important decision factor, because GWT debugging was the most frustrating thing for me.
Consider JSF + some nice rich component framework for JSF like RichFaces, IceFaces, PrimeFaces etc (but you app won't be "light" and "small" anymore if you really care). Be sure to be perfectly comfortable with environment (IDE + plugins), nothing beats JSF there (I'd pick RichFaces + Seam today, if full Java EE is option).
If you don't want to learn javascript I recommend you GWT with Sencha-GWT (GXT), you can develop all your app in java language, and also debug your code in java.
It is very easy to create a web app with this technology, and provides almost all funcionality available in javascript version.
Also you can mix it with hibernate and giled to persist your data, and giled helps you to serialize hibernate objects.
I have been writing an application in SproutCore for the front-end and a Java backend. In my mind this works perfectly.
The backend can stop worrying about HTML and JavaScript contents on the client side, if the request is XHR or plain request/response. I can implement the backends using plain old Java Servlets, and only worry about the data that is passed between the client and the server (JSON for the most part).
The client becomed fast and responsive, and SproutCore has a rich amount of components that you can mix and match.
So in other words with SproutCore (and Cappuccino and other full-blows MVC JavaScript frameworks) you can let your client do what it does best : Render and display HTML, CSS and JavaScript, while leaving your server to worry about what it does best: retrieve, store and update data. If you are interested, the source code for this project is available with the GPLv3 licence: https://github.com/joachimhs/EurekaJ
I have written an article about the differnt approaches between server-side MVC and client-side MVC here: http://haagen.name/2011/05/24/The_RIA_MVC_Model.html.
Also SproutCore comes with the MIT licence, so its avaiable for use without (m)any restrictions.
I read through a few threads (simple web framework, java web development, etc). Very informative. However I have not seen a focus on the AJAX side of things. For the app I am trying to create, most of the client side will be written in Google GWT, and JSON will be used to communicate with the server side. In that case, all templating is pretty much useless.
For my purposes, which framework would be the simplest to setup and easiest to learn?
Thanks.
To clarify, I want a server side framework. GWT is great for client side, but I need something to generate json responses on the server side.
None at all, most likely: GWT is framework enough, given that's what you're using. The only reason I can think of to add anything else might be if there was some special effect you absolutely craved (but if you've chosen to go GWT, my recommendation would be to give up on such special effects),
Ajax/JS by nature functions mostly on client side and you want to use it but want to run it on server side? Are you sure you're not trying to hammer a square block into a round hole?
Reading through your question it seems to me what you're really asking is for a way to abstract a layer which provides JSON for your client side UI. Most web frameworks such as GWT deliberately abstract this part away but still include it in their inner workings: it would indeed be rather stupid for an Ajax web framework not to support data transfer between the view layer and the rest of the system!
However, if you really want to create your own custom component for serving JSON, then I suggest you take a good look at Servlets and mix that with any of the gazillion available JSON libraries listed at JSON.org.
And if you still really, really want to run your client side view logic on server, Vaadin could do the trick for you. In practice Vaadin really runs GWT on the server side and just serves static stuff generated by the server side GWT but from what I've understood the difference has been abstracted away.
A huge word of warning though, for me it sounds like you really want to reinvent the wheel here while you shouldn't. You really should reconsider your architecture and/or deepen your knowledge of GWT and web frameworks in general, the "framework" part usually hints that it's not just the V from MVC Model 2 but at least V and with M bindings.
I've had pretty good luck with the Dojo Toolkit. Make sure to download the full toolkit (Dojo, Dijit and Dojox) which you'll find at the downloads page.
Their 'Hello World' tutorial is pretty useful for getting started.
You could could give IceFaces a try. It's a Ajax framework based on faces technology. Works really great and magically, also comes with a good documentation and tutorial.
You should look at one of the REST based frameworks, like Jersey, Restlets, or RESTEasy.
The main reason is that these frameworks make binding and working with JSON easy. Most of the other systems are designed for HTTP POST encoded data, which is not JSON.
There are zillions of Java web application frameworks.
95% were designed before the modern era of AJAX/DHTML-based development, and that means these new methods are grafted on rather than designed in.
Has any framework been built from the ground up with e.g. GWT + Extjs in mind?
If not, which framework has adapted best to the world of forms with dynamic numbers of fields and pages that morph client-side?
Echo2 / Echo3 by Nextapp (www.nextapp.com) is totally awesome.
Advantages over GWT:
1) It is not limited to a sub-set of java like GWT
2) It is easier (in my estimation) to learn
3) Has extremely robust design studio for almost drag and drop designing.
4) It is very fast, and works very well on all platforms browsers
5) You can write your application using either java script or java
6) It has great and straight forward methods for handling events and actions.
Personally I think that for any web-application in which you are trying to integrate java and speedy delivery I wouldn't hesitate to pick Echo3 or Echo2.
If you're starting from scratch. I'd have to say Google Web Toolkit. I have to say it is incredibly powerful. You get keep using most of your Java tools. Plus, you don't have to duplicate code that exists on both the server and the client, it just gets compiled differently for each area.
I'd consider REST-style frameworks as well as the other recommendations here- Restlet or Jersey may be good choices for the backend, while you use something like JQuery or GWT on the front end. Both frameworks can easily produce JSON, and the REST style provides a nice clean line of demarcation between your client application and your server source; I find that JSF can make that demarcation pretty muddy.
I use JSF and IceFaces. Although JSF has a few limitations, IceFaces seems to work pretty well and has ironed out a few of the problems with JSF.
I haven't used a really good AJAX Java framework as yet, although Echo2 looks interesting.
I like the stripes framework. It lets you use whatever javascript toolkit you want.
Here is their documentation on AJAX
GWT is quite powerful and easy to use (all Java, no Javascript/HTML/CSS coding). If Google has their way it will be a dominant framework/tool in web applications development, and for good reason. It already works with Google Gears (which allows offline access to web apps) - and more than likely will be optimized to work within Google Chrome.
DWR
I use this to dynamically populate drop downs, and even filter them on the fly based on user input in other places on the form.
I like the combination of JBoss Seam and Richfaces, especially with the JBoss tools that are extentions to Eclipse - makes building these sort of RIA's incredibly easy.
Wikipedia contains some useful comparisons:
Comparison of JavaScript frameworks
List of AJAX Frameworks
Your choice depends on several different factors including whether you want the "work" done client-side (most javascript frameworks) or server-side (echo2 etc.). Other things worth looking at are tools like OpenLaszlo that provide Flash (I think) out of the box, but drop back to DHTML if there is no Flash player present.
Unfortunately I think the decision comes down to balancing several competing cocerns. Check out the comparisons and try them out - most come with online demo's for you to try.
Aptana has a server side frame work called Jaxer. This is from their site:
Jaxer's core engine is based on the same Mozilla engine that you'll find in the popular Mozilla Firefox browser. This means that the execution environment you use on both the client and the server are the same. It's Ajax all the way through and through. That means you only need one set of languages -- the languages that are native to the browser -- to create entire applications.
This framework is open source and has a very nice IDE based on Eclipse. Aptana is also working on a Javascript implementation for ActiveRecord called ActiveRecordJS. Potentially you could use this both client and server side with their framework.
GWT is one of the best AJAX framework that I used ever. Most important thing about this framework is that its maintained by Google. And Everyone know "Who is Google ?"
GWT is used by many products at Google, including Google AdWords and Google
Wallet. It's open source, completely free, and used by thousands of
enthusiastic developers around the world.
GWT provide rich widgets that can be used to built any application. Almost all the widgets they have.
Another important point is GWT is continuously developing and its also have stable release which is very good thing. Another thing Google has also released GWT-Material which is again a very good thing because everyone is moving toward material.
I hope this will help you!!!