I am trying to create an application which will have different views for mobile, desktop and tablet. It is on the lines of MobileWebApp sample from GWT. I am looking at GWT MVP tutorial and have a basic app working.
I was thinking if I should use GWTP and if there would be any advantages of using GWTP instead of GWT MVP(activities and places)
Also, any ideas how different views would bind to the same presenter. There might be differences in what features are available on mobile view and desktop view.
I have done something like this, although at a time before Activities and Places. So back then I've written the MVP framework myself. I placed all the common code, such as Presenters, TransferObjects and Utilities in a separate GWT module. Then each UI became a separate project as well, holding it's View classes and UiBinder stuff, inheriting from the common module. So actually each UI project is a complete GWT application. The GWT applications have to be deployed under different context, thus have different URLs. You then need some smart JavaScript on your welcome page to redirect a visitor depending on there device.
I don't think you can solve this in one GWT app. Or you'd have to come up with a really really clever solution using Deferred Binding (probably it's replacement functionality) and the Linker subsystem.
You can create different views in for a presenter in gwtp. GWTP makes it easier to handle such a scenario. There is an open-source Customer Experience framework which has a sample to create a mobilewebapp using GWTP. You can check it out here- http://code.google.com/p/gwt-cx/
Related
I have a GWTP application which has no entry point because I don't ever need to run this application on its own. Rather I want to use it within a standard GWT application which has an entry point, implements its own history management mechanism, uses its own implementation of MVP framework, has its own dependency injection and so on.
The question is: Is it even possible to nicely integrate a GWTP application within a standard GWT application?
Consider this use-case for example: I want to show a popup dialog when a button is clicked in a view that is implemented in the GWT application. The popup dialog is a GWTP PresenterWidget implemented in the GWTP application. How is it possible for a non GWTP presenter to show a popup and make sure all life cycle events are properly called.
I know it's a broad question but I'm looking to see if any body has ever tried to integrate two such applications together. If not is there any advice on how to approach this problem at all.
Thanks in advance
In that kind of context, I would suggest to build your home made mvp framework. It would be easier and cleaner than using a subset of the capabilities of GWTP.
That being said, it's not imposible, but you will have to use a complete hierarchy of presenter / presenter widgets. But that won't mean that the lifecycle will work... The lifecycle of GWTP is strongly tied to internal Navigation Events and if your application doesn't use this feature of GWTP, you're likely to lose all its advantages.
Here's how you can embed a GWTP application in your own already existing application:
https://github.com/ArcBees/GWTP/wiki/Website-Embedding
We've already worked on migrating an existing application to GWTP by embedding the existing application IN GWTP while gradually migrating the existing code base, but not the other way around.
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 am looking for a framework/library that generates most/all of the generic MVP code itself, so that I can then extend that code. In default GWT-Eclipse IDE setup, I have to write every bit of code by hand.
I have seen a few frameworks like Tessell which aim at generating a large part of the boiler plate code...Which framework do you recommend for this purpose, so that I can create new MVP-GWT apps with minimal effort/fuss?
Take a look at Tessell:
Tessell is a GWT application framework
Follows a Model View Presenter architecture
Less boilerplate (10x less LOC than hand-coded MVP)
Features
View generation of the MVP/UiBinder interfaces/implementations that allow for fast, DOM-decoupled unit tests but that suck to code by hand
Rich models to make your application's presenter/business logic more declarative and have less spaghetti/inner class code
Dispatch-style server/client AJAX communication
Stubs for awesome, out-of-the-box tests
Conventions for forms, row tables, and cell tables
I know people who have used mvp4g on some large projects effectively.
I used gwtp in two projects and it worked really well.
It has the concept of nested presenters/views which might come handy if you want to create reusable MVP components.
The GPE (Google Plugin for Eclipse) and Google Window Builder together will generate most of what you need for MVP code using the GWT libraries. You go to New ->Window Builder->GWT UIBindder->MVP->MVP View. The Wizard will generate the uibinder code, a UI interface, a UI implementation, a place, and an activity. It will also use a client factory if you are using one. If you have a client.place and/or a client.activity package(s) it will also put the places and activities in those packages for you.
I've been looking into GWT and MVP recently and to be honest I'm very confused. My project will include around 40 different places or views all together. While reading multiple tutorials, some follow Model-View-Presenter and others use Activities and Places, all under the subject of MVP, GWT.
I'm not sure what to follow for a new MVP, GWT 2.2 project.
Many thanks,
Alex
Alex,
Activities and Places are Google's implementation of the MVP framework. There are many well established additional MVP frameworks for GWT which encompass many additional features not yet incorporated into GWT. The two I would recommend are:
GWT Platform: http://code.google.com/p/gwt-platform/
MVP4G: http://code.google.com/p/mvp4g/
They have many additional features to reduce the amount of boilerplate code you have to write to implement solutions. They are worth a peak before choosing Google's A&P.
Cheers
Gene
Activities and Places is the MVP solution that was implemented in GWT 2.2. Before that, MVP was only a recommended approach without an official framework provided by Google. That's why you're getting confused.
I would recommend you to stick with Activities and Places, since it's the official Google solution for MVP.
I hope it helps.
It turns out that an Activity takes the role of a Presenter in the MVP design pattern. Not all of your presenters need to be Activities, but if you have an Activity you can think of it as being a special kind of Presenter with a well-defined lifecycle used for transitions from one "place" to another.
So it's not a choice between MVP and "activities & places". Rather, they're all of the same idea. The new activities & places framework is just a refinement.
Alex,
Activities and Places (as well as ActivityMapper and more) are classes which the GWT team provided to formalize their earlier MVP pattern recommendations. Some time ago I've tried the "raw" MVP recommendations and am currently using the higher-level approach the aforementioned classes provide. It certainly feels easier to use the new classes. In addition to a nice MVP abstraction, you get the important aspect of handling browser history navigation in your application practically for free.
The MVP API is here to stay, it seems, so if you're using GWT 2.2.x I'd also recommend utilizing the new MVP classes from the inception of your project.
Activities and Places are not a MVP framework! Google removes this "disturbance" in later docs. it is just a browser history framework (to easily (de)serialize state of the app). but on implementing MVP and using A&P it turns out that in many cases it is a good idea to merge activity and presenter.
in a more general case one activity could start n presenters.
We used activities and places along with presenters in our design. We also used MVP.
The setup was a view, viewImpl, and inside the view interface, if needed, was a presenter interface that was also declared. The view interface was a pass through to the viewImpl implementation class. The activity went to the viewImpl based on it's business logic and in our case, the viewImpl went to a stand-alone composite widget.
If it was needed, the composite widget used a presenter to get back (another pass through) to the activity. No business logic was in the view or the viewImpl by the way, that was only in the activity. It worked well!
I am working on a GWT app that needs to serve a different layout to mobile device users. I can easily determine if a user is using a mobile browser; however, I'm not sure about the best pattern for handling them.
I am currently using the MVP pattern - would it be best to simply pass a browser-specific view to the Presenter or is there a more appropriate method?
You could set up GWT to detect the web browser used, as described in this question. Then, via Deferred Binding, let the compiler "slip" the correct view into place for the, say, mobilesafari user agent. That way, you won't have to litter your Java code with browser detection, etc.
The way I've done it is to have different GWT modules (with their own entrypoint, Gin modules, even different CssResources) and then on the myapp.html page you just have to check out what browser is requesting the content and based on it (javascript checks) the appropriate module
<script src="myapp/myapp.nocache.js"/>
or
<script src="mymobileapp/mymobileapp.nocache.js"/>
is loaded.
If you are working with GIN and an MVP framework (gwt-platform is my platform of choice) you can then reuse the code that was already written for the presenters and only implement different views.