From my understanding Vaadin consumes GWT and adds an engine on the browser end to interact with server side UI. In looking for a 'Confluence' Vaadin add on I came up with nothing. I would like to use Javascript instead of Vaadin pure Java to talk with Confluence 'rest'. However I believe that I found find some GWT Confluence plugins. Since Vaadin uses GWT already do you think a GWT confluence plugin is the way to go? Also there is a angularjs/vaadin addon and then I could us angularjs with Confluence. Your thoughts please...
The traditional Vaadin Framework consists of a java backend on the server and components which are rendered on client side. Most of those are client side rendering are written with Java/GWT.
In addition to this, there exist the Vaadin Elements, which are "pure" JS components for the frontend.
Is Vaadin Elements meant to be used with the Vaadin Framework?
If you wish to write a app with all logic client side (And perhaps calling some REST api), then you will need to write this in JS (perhaps with Angular/Polymer etc.).
In that case you could use the vaadin elements for some of the tasks, but you will remain in the JS world.
To answer your question:
Using a GWT thing and combining it with JS isn't the most up-to-date way to handle things.
GWT makes sense when you wish to write frontend code with Java but certainly not for JS.
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.
Good day. I'm still learning GWT so please help me. I'm working on a project - Web Application with GWT on the Client Side. This app has lots of CRUD operations so I'd like to make a model for this. Can anyone suggest a prototype for my CRUD class?
CRUD on this app goes something like this:
When I clicked the Details button in a module, a popup will be shown that allows the user to do CRUD operations. This popup do have the module title, info on the selected item, and the buttons - Edit, New, Delete.
I have already finished building the base GUI for this project but I'm just starting to work on each module. I choose to begin on those module with CRUD operations. So, please help me and give your ideas on this project. Thanks in advance :)
Your question is a little bit general.
You probably have to deal with two questions which can be handled separately:
Communication with the backend.
GUI for CRUD operations
Communication with the backend:
It depends on which kind of backend you are using.
Java-backend:
For Java backends the recommended client-server communication protocol is RequestFactory.
Non-Java-backend: In case you are using a non-java backend (python, PHP, etc) you have to use RequestBuilder using JSON or XML (I would recommend JSON).
For mapping JSON/XML to DTO's and vice verca you can use different methods:
Third party tools like piriti which are based on GWT generators
Javascript Overlay Types (JSO)
GWT Autobean framework (which is used by RequestFactory btw).
GUI for CRUD operations
For mapping your DTOs to your UI and doing the CRUD operations you can do it either:
manually
with the Editor framework
I would recommend to use the Editor framework as it reduces the amount of boilerplate code
to move an object from your object graph to the UI and back.
The Editor framework works well with RequestFactory (RequestFactoryEditorDriver), Autobean (SimpleBeanEditorDriver) and Javascript Overlay Types.
Can anyone suggest whether "GWT" or "Vaadin" are a better choice to design an application? Also: what are the differences in coding style?
In GWT application logic is normally run on client side. It only calls server when it needs to read/save some data.
In Vaadin application logic is on server side. Client side must normally call server after every user interaction.
GWT advantage:
App logic (replies to user interaction) is faster as it is run locally in the browser. It's also relatively insensitive to bad network conditions. Network is used only when needed (to read/save new data), which saves net traffic (important for high traffic sites).
In this regard Vaadin is slower and introduces a lag in UI interaction which is annoying to user. If network is bad this will show in UI responsiveness.
Vaadin advantage:
App logic is run on the server so it can not be inspected by the user. Arguably (Vaadin claims) that makes it more secure.
A few more points:
A fundamental difference is that in GWT you have to separate your application into Client and Server code, no such distinction in Vaadin. This will affect the architecture of your application.
In GWT client code, you must code in Java, and have a limited subset of language features available (that the GWT compiler can translate into Javascript). In Vaadin, you can code in any JVM language, since everything runs in the server (I'm using Vaadin with Scala). This may or may not be relevant to you.
GWT compilation is VERY slow, although in development mode you have the emulator. This makes production environment updates painful (a GWT application I developed has grown pretty big, and currently takes around 15 minutes to compile).
It's very simple to extend GWT with 3rd party widgets, or roll your own. Creating new Vaadin widgets is more complex.
Another Vaadin advantage: you don't have to design or implement the client-server communication, that's built-in.
With Vaadin you can also use built-in GWT when you want to do something on the client-side. This gives you both simplicity of server-side programming model (no communications, no browser programming needed) with being full control of what happens in the browser.
Differences between Vaadin and GWT:
A) Vaadin includes a server-side development model that:
Cuts number of code lines to half by reducing layers one has to
implement for user interface.
Allows you to use any JVM based language for user interface - Scala,
Groovy
Increases security by keeping user interface logic in the server
Allows synchronous calls to any backend API from the web server
Allows use of any standard Java libraries and tools for UI layer- in
server side architecture applications
Does not need Java to JavaScript compilation step that often takes
time or makes tooling complicated in GWT projects - instead you have
the Vaadin client engine
Provides server push out of the box with no extra code needed
B) Vaadin provides a large set of high level user interface components. For GWT one would need to use commercial Sencha GXT for comparable component set.
C) Vaadin includes SASS based Valo theme engine that makes it easy to build good looking custom themes from your application. Valo is the latest theming for Vaadin.
D) Data binding: Vaadin has incorporated the ability to associate any widget directly to a data source such as database, file or anything else in the server-side. This enables to define default behavior of the widgets to act on data sources.
Vaadin vs GWT
tl;dr
whether "GWT" or "Vaadin" are a better choice to design an application
It is not an “either-or” question.
With Vaadin, you get GWT (or its counterpart, Web Components) plus much more.
Vaadin is a framework for building desktop-style web apps by writing pure Java code on the server-side including declaring a user-interface. That user-interface is rendered in a web browser by Vaadin automatically generating on-the-fly the necessary browser code: HTML, CSS, JavaScript, etc. Business logic executes only on the server-side. User events (buttons clicked, data typed into fields, etc.) on the web client trigger Java code to run on the server side.
How that browser code is generated and executed, and how the client and server communicate, depends on 3rd party technology:
In Vaadin 8 and earlier, GWT
In Vaadin 10 and later, Web Components
Vaadin 8 and earlier uses GWT
Vaadin 8 and earlier was built on top of Google Web Toolkit (GWT). GWT has been spun-out of Google, as a fully open-sourced project: http://www.GWTProject.org/
GWT cross-compiles Java code into standalone JavaScript files. GWT provides other important features such as support of UI components and client-server communications.
The Vaadin Ltd company is a major supporter of GWT, including having hosted GWT developer conferences, and providing consulting expertise services.
Vaadin is only one of many products built on GWT.
Vaadin 10 and later uses Web Components
Vaadin 10 and later, known as Vaadin Flow, is a major rewrite of the framework. Instead of using GWT underneath, Vaadin Flow is built on top of Web Components technology.
Web Components is actually a suite of technologies including Custom Elements, Shadow DOM, and HTML Templates. These technologies are now built into most every modern web browser, and supported on many older browsers via polyfills.
Writing a new widget component for Vaadin is much easier with Web Components than with GWT. And most any existing Web Components based component can be wrapped to provide access via Java from the Vaadin server-side framework.
I don't have a source at hand to cite, but as I recall, Web Components based widgets may run faster and use less memory than their GWT-based equivalents.
By the way, both generations of Vaadin depend on some other technology, such as the Atmosphere library for help with WebSocket and HTTP.
I haven't tried Vaadin. I'm a GWT fan, but I CAN say that I've been a bit disappointed by the default widget set provided with GWT. You really need something like SmartGWT to fill the framework out.
I belive Vaadin is a much more advanced framework than GWT
BUT
When it comes to optimise performance on the client side there is nothing much you can do unless you build your own components (and that's where the beauty of Vaadin stops)
In a project i'm working right now 90% of the staff I've done worked as a charm
And then I had to use an event timeline next to a couple of tables. When I loaded more than 400events on the timeline my web page was almost unusable not to mention terrible slow on initialisation. I've been trying to optimise the code the last two months. At the end I used a GWT component.
As any application has to show display information coming from the server, a major requirement for simple coding is automated data binding to your forms and tables.
With Vaadin, this is as simple as a few lines of code.
In GWT, first you have no table mapping.
As for forms, you can map an object to a form, but to do so you have to implement a so called GWT Editor for your object (and one for every object inside of it). An Editor is nothing else than the definition of the form to use to show/modify the object. So all in all, there is no automation here.
GWT enables you to write web-clients with Java. The GWT cross-compiler creates JavaScript code for the client-side. You have to care for the server for your own as well as client-server communication. The generated client-code is already optimized for many browsers. My personal opinion is, GWT was very popular until Google focused on Angular. Today it is not much popular anymore.
Vaadin provides two different solutions:
1) a UI widget-set based implementing the web-component standard, and
2) the Vaadin serverside Java framework. It allows you to write web-clients with Java. However, Vaadin generates the web-client through runtime on the server dynamically. Vaadin cares for the entire client-server communication. For rendering the UI, Vaadin until version 8 used a pre-compiled UI widget-set. Vaadin from version 10 uses the Vaadin web-components.
Further benefits of Vaadin:
You do not get in contact with HTML and JavaScript and you need not bother for DOM manipulation, browser history and other low-level problems
The serverside architecture provides better security
Modern themes
Individual styling with CSS
RapidClipse provides a powerful UI builder for Vaadin based on Eclipse containing a Vaadin <> JPA databinding, internationalization, UI persistence, extended Hibernate tools, JPA-SQL query language and MicroStream integration for creating Java in-memory database apps and microservices
Is there a mechanism to dynamically load a GWT Module?
The idea is to create a pluggable GWT-based system: a core GWT module that dynamically loads another GWT module and a bus communication system to permit the communication through loaded modules.
Any help?
Possible duplicate of Web Application using OSGi and GWT
Also, see the information in this GWT User forum thread - http://groups.google.com/group/google-web-toolkit/msg/4a3f912cb89a7256
To summarize, its possible, but not recommended. Your requirement is orthogonal to GWT's philosophy and architecture. If you must, the GWT Exporter project is a useful starting point to enable communication between modules.
Code splitting does successfully handle the separated-loading issue -- but it does not address the separated-compilation issue.
Modular-interoperability with separated-compilation will never be the recommended default but GWT team should look into this in future.
If we are talking about a plug-in based architecture, different plug-in developer should develop their own UI and compile and give to the framework. Framework should dynamically load them.
I am still looking for and way to do it (do it better way).
You can use code splitting to dynamically loading the code when ever you want.
Have a look
http://code.google.com/webtoolkit/doc/latest/DevGuideCodeSplitting.html
See also comments at http://code.google.com/p/google-web-toolkit/wiki/CodeSplitting, starting at 6th comment.