Building Standalone Applications in JavaScript

Question

With the increased power of JavaScript frameworks like YUI, JQuery, and Prototype, and debugging tools like Firebug, doing an application entirely in browser-side JavaScript looks like a great way to make simple applications like puzzle games and specialized calculators.

Is there any downside to this other than exposing your source code? How should you handle data storage for this kind of program?

Edit: yes, Gears and cookies can be used for local storage, but you can't easily get access to files and other objects the user already has around. You also can't save data to a file for a user without having them invoke some browser feature like printing to PDF or saving page as a file.

Answer 1

I've written several application in JS including a spreadsheet.

Upside:

• great language
• short code-run-review cycle
• DOM manipulation is great for UI design
• clients on every computer (and phone)

Downside:

• differences between browsers (especially IE)
• code base scalability (with no intrinsic support for namespaces and classes)
• no good debuggers (especially, again, for IE)
• performance (even though great progress has been made with FireFox and Safari)
• You need to write some server code as well.

Bottom line: Go for it. I did.

Answer 2

Another option for developing simple desktop like applications or games in JavaScript is Adobe AIR. You can build your app code in either HTML + JavaScript or using Flash/Flex or a combination of both. It has the advantage of being cross-platform (actually cross-platform, Linux, OS X, and Windows. Not just Windows and OS X).

Heck, it may be the only time in your career as a developer that you can write a web page and ONLY target ONE browser.