Anyone know of any tutorials implemented across multiple web application frameworks?
For example, I'm starting to implement GWT's Stock Watcher tutorial in Turbo Gears 2 to see how difficult it will be to do in Turbo Gears 2.
Likewise, I'll be looking for a Turbo Gears 2 tutorial to implement in GWT.
But I hate to re-create the wheel - so I was wondering if anyone was familiar with such projects and/or would be interested in helping me work on such a project.
Thanks,
--Spencer
While it is possible to combine the two frameworks, I hope to convince you not to do so.
Most web-frameworks, including Turbogears, have server-side page flow management. A page is served to the user by generating html, user interacts by clicking on links or by posting a form, the browser sends a fresh request to the server, and finally server responds with new html altogether. You AJAX'ify the page by using a js library, or the framework has some support. But, in general, transition from one view to another is done on the server side.
GWT is totally different. There is only a single HTML page in the system. Once this page is downloaded, everything happens on the browser through javascript. When the user clicks on a link, its essentially just a javascript function call. History management is done through fragment urls (the portion after the #).
These two philosophies are poles apart. So apart that I daresay GWT doesn't work well with any server-side web technology. See this discussion on GWT vis-a-vis JBPM/Struts/Spring Webflow. And see this discussion on GWT v/s JQuery.
Related
in standard "page-based" webapps, it´s quite easy to implemet direct links to several pages, f.e, an url abc.com/app/customer/4711 which directs the user directly to the page diplaying customer 4711.
Is there a way to reproduce a similar behaviour in an GWT-App?
Tnk Mica
You can use Activities and Places design pattern. It provides easy access to any "place" within the app:
https://developers.google.com/web-toolkit/doc/latest/DevGuideMvpActivitiesAndPlaces
Every once in a while this question is being asked in one form or another and I think misconception exists about what GWT is best suited for.
GWT is an amazing set of tools for creating web applications: JavaScript multi-screen user interfaces which run in modern web browsers, load as a single web page and generally don't need full page reloads or page switching for their operation.
Navigation between screens happens in response to triggered events (for example, a user pressing a button, a timer firing or server-side state changing). The data needed to be presented is acquired asynchronously via XHRs (again without web page reloading).
GWT provides an elaborate framework for all of the above - Activities & Places for navigation, as Andrei mentioned, GWT-RPC and RequestFactory for data acquisition and exchange, and much much more to make advanced and highly-structured web apps which leverage the processing power of modern machines and capabilities of modern browsers.
First off, I've never used GWT before. I have good experience in HTML/CSS/JS/JSP.
I'm looking for people's opinions on the suitability of Google Web Toolkit for a brand new web app I'm developing.
A big requirement is that the UI is attractive and well designed (Does not look like a clunky Java/Swing App).
It should look like any typical HTML/CSS/JS based modern website.
It is an internal company application so no SEO is required.
JSF is not an option.
The web app frameworks used will be Spring Webflow and Spring MVC. It will use lightweight controllers to communicate with a service layer.
Would Spring Tiles combined with JSP be an easier or more flexible option than GWT for what I am trying to achieve?
Advantages/Disadvantages of GWT and other options welcome.
Thanks
Advantages of GWT
You don't really need to know any JavaScript, since all your client side code will be in Java
This is usually the main reason people go for GWT. They're backend developers who know Java but don't know Javascript, and they don't really want to learn it. Still, you should be careful about this. GWT is a very complete and complex framework with many concepts that are specific to GWT. Even though you'll be coding in Java you will still have to go through many tutorials and documentation before you can build a clean GWT app
Ready to use widgets, like date pickers, dynamic tables, layout panels, popups
It's not really specific to GWT. Other front end framework, like jQuery or Dojo or whatever also give you these. You can have a look at the GWT Showcase to see what GWT has to offer.
GWT takes care of a lot of complex and potentially dangerous stuff for you.
Stuff like Cross-Browser Support, Internationalization, Image and static resources bundling, Front end security, Ajax communication with a server, Events and MVP (just like MVC) framework support. Have a look at the documentation, it is very well done and very thorough.
Debugging is easy
GWT has two different 'modes'. When you're building your app for production, gwt will compile all the java code for the front-end that you wrote into javascript. This javascript will be executed in your clients' browsers. But when you're developping, you can run your app without compiling your java code to javascript. This lets you use a debugger to debug your interface. It's a very good tool.
Disadvantages of GWT
As I said before, GWT is a full framework, with concepts specific to it. Don't think that just because it's in java and you know java that you won't have to learn new stuff.
Interfacing GWT with back end frameworks is not easy
The most common way for your GWT client code to communicate with a server is by using GWT RPC mechanism. It means that you will need to have servlets that implement specific interfaces. You should definetly read the docs on client-server communication to see if that fits well with Spring. A search on SO or Google should give you pointers to setup your application.
I want to develop a Web Application by combining Spring Framework, GWT, Servlets, JSP........
I plan to develop Server side using Spring,Servlet ,JSP....
And for Client side, GWT....
The Output page(Response page) of my Application, will given by JSP only....
Then what is the use of GWT at client side....
please clear my doubt....
Read the following
1) AJAX - http://en.wikipedia.org/wiki/Ajax_(programming)
2) RIA - http://en.wikipedia.org/wiki/Rich_Internet_application
3) GWT - http://en.wikipedia.org/wiki/Google_Web_Toolkit
The problem with using purely jsp to create a web application is that each user interaction typically requires the entire page to be reloaded. Depending on what you're doing this approach is considered outdated. GWT is built on top of javascript and xhttp requests, allowing user interactions to affect only relevant portions of the page. This generally results in a faster and smoother user experience.
If you have already decided that you want to use JSP, then you don't need GWT. Although you could use it to create custom dynamic components and embed them on your page. Or to create a part of your application where you find JSP not sufficient (which would be probably a part that should be more 'dynamic' and would require a lot of javascript).
http://code.google.com/webtoolkit/overview.html#how
We're planning on creating a feedreader as a windows desktop- and iPad application. As we want to be able to show Websites AND to run (our own) JavaScript in this application, we thought about delivering the application as HTML/CSS/JavaScript, just wrapped by some .NET control or a Cocoa Touch webbrowser component. So the task at hand is to find out which framework to use to create the HTML/CSS/JS files to embed in the application.
For the development of the HTML/CSS/JavaScript we would be happy to use Vaadin, GWT, or some other framework, as we're a lot better with Java than with JS. We favor Vaadin after a short brainstorming, as the UI components are very nice, but I fear that most of the heavy lifting will be on the server and not in the client (and that wouldn't be too nice). We would also like GWT, but the Java-to-JS compiling takes a lot of time and an extra step, and slowed down development time in the past when using it.
The question is: which development framework would you choose (given you wanted to implement this project and you mostly did Java so far) and why? If there are better framework options (List of Rich Client Frameworks), please let me know.
Edit: The application will need to talk to our server from time to time (sync what has been read for example), but mainly should get the xml feeds itself. Therefore I hope that most of the generated code can be embedded in the application and there doesn't need to be heavy activity with our server.
Edit2: We (realistically even if you doubt) expect at least 10000 users.
Based on my experience with Vaadin, I'd go for that, but your requirements are somewhat favoring pure-GWT instead.
Vaadin needs the server and server connection. If building mostly offline desktop application, this can be solved with an embedded Jetty for example. (synchronize with an online service only when needed), but for iPad you would need to connect online right away to start the Vaadin application.
GWT runs completely at the client-side and you can build a JavaScript browser application that only connects when needed.
Because Vaadin is much quicker to develop, you could build a small Vaadin version first and see if that is actually problem on the iPad.
On the other hand, if you can assume going online right away, you can skip the local server installation altogether. Just run the application online and implement the desktop version using operating systems default browser control (i.e. the .NET control you suggested). Then Vaadin is easier.
Vaadin is just framework base on GWT but have two very important features:
don't need to run GWT compiler. It is pure java. Of course if not add addons because then gwt compiler must run.
you don't need to write communication code. So you don't need to solve DTO problems, non-serializable object mappings and dont need to write servlets.
I use Vaadin in my work for one year and we haven't performance problems yet (desktop like application with ~500 users). IMO very good solution is to use Vaadin just for UI, logic move to independent beans and connect this two elements using Spring or Guice.
In this case you should use MVP pattern and Domain Driven Development.
Bussines beans is domain objects and logic that use view interfaces to send responses.
Custom Vaadin components (could extends standard components) implements view interfaces.
That way is good when you decide to change UI engine if Vaadin is not for you. Just rewrite guice/spring mappings and write new implementations of view interfaces.
My 3 cents:
If you decide to use vaadin, You will benefit from already GOOD LOOKING components. Since you dont want to write (alot of) CSS , vaadin is already good looking out of the box. How ever, Vaadin is a SERVERSIDE framework. User interface interactions will hit the back end even if they dont involve getting any data (e.g moving from one tab to the other) .
If you decide to use GWT, you will have to atleast style the application (this is not hard) . There is also the problem of long compilation time (but you can test and debug on hosted mode which allows you to run the application without compiling , then you compile only when deploying). The main advantage of gwt is that you control what gets sent to the wire, For UI interactions that dont require getting data from the backend, it will work purely on the client side. You the developer will determine when to send a request to the back end. (Doing RPC requests in GWT is very easy)
Hope this will help you make the decision.
My friend and I want to develop a big web2.0 project. We decided to write it in Java because we love it and we are good at it and the other libraries which we will use are written in Java (Apache Lucene, Apache Cassandra ...). and we choose GWT as a framework. We love google, google technologies, google apis.
and I want to ask do you think that GWT is suitable to launch the big projects like youtube, twitter, wikipedia and other... ? Is gwt-rpc mechanism reliable in big projects?
Well GWT is suitable for web applications and not web sites or web pages, GWT is suitable for applications like Gmail which is a BIG application yet contains a single page which has complex actions.
GWT fails in some projects with many pages, We used GWT in an ERP system which contained about 100 page each page represents CRUD operations + some business operations, GWT wasn't the perfect choice.
Other thing GWT may fail in is that web crawlers can't extract information from javascript files generated by GWT. Search engines prefer static HTML generated from server side, and not generated on client side by javascript as GWT does. So, Google search engine will not give results from your site.
In summary, GWT is suitable for web applications with fewer number of pages and more complex actions.
Your examples (youtube, twitter, wikipedia) are not good candidates for GWT, so if you're building that type of application you'll probably want to stick to traditional server based frameworks like SpringMVC or Spring Roo.
GWT is better suited for applications that would traditionally be desktop based and need to do a lot of processing on the client side such as email clients, games, reporting apps, word processors, etc...
I want to point out that "in big projects if generated javascript codes is larger and larger, User is obligated to wait to download js file before to use web site."