frameworks choosing strategy for multi platform webapp

Question

Issue

What is your strategy for building a desktop-like webapp that needs to be deployed to desktop web browsers and on mobile devices(Android, IPhone, etc)?

A course of action could be to firstly select the best framework for building the part that runs on computers(i.e. not mobile devices). Being a desktop-like app, a good candidate framework is GWT+ExtGWT since it provides:

• Java-based development which is much scalable/solid than developing in Javascript via ExtJS for example
• Good debugging
• Good testability

Next, you'd want to deploy this app on mobile devices too. So how do you go from here? Write a separate implementation(separate from GWT) for Android, another one for iOS(in objective-c), another one for Windows Mobile, and so on?

Related

Related to above, I saw the presentation of PhoneGap which claims you develop in Javascript+HTML and it generates code for all mobile platforms: Android, iOS, etc.

However, PhoneGap is not an option since I don't think it integrates well with GWT and more important, it doesn't generate a native app which can take advantage of features like backgrounding, services, etc(see http://www.youtube.com/watch?v=xHXn3Kg2IQE for why native Android apps are much better than browser-based ones). There may be other frameworks like PhoneGap out there that I'm not aware of though but at this point I only see:

• one implementation with GWT
• one implementation for Android
• one implementation for IPhone
• and so on ...

Answer 1

If you are already planning on developing for multiple platforms, it is a good idea to at least consider cross platform frameworks like PhoneGap or Appcelerator. Beyond the fact that you are developing for multiple platforms there are a couple of other important questions to consider.

1. Do you want a web version as well?
2. Do you need intensive graphics support?
3. Do you have loads of money to target multiple platforms?
4. Do you have loads of time to target multiple platforms?

You also point out two more great questions to consider in debugging and testability. In terms of unit testing, any native platform is very difficult to unit test. Debugging is pretty easy for most native platforms.

Regarding PhoneGap, it is important to know a few things about it.

You can write PhoneGap plugins. A plugin is essentially native code for any given platform that can do pretty much anything you would want to do in native code -- background services, opengl, etc -- and make it accessible to JavaScript in the web view.

There are several open source projects that you might be very interested in such as GWT-PhoneGap, QUnit for JavaScript unit testing, and Weinre for Firebug like debugging.

Hope that helps!