Google Developers Blog: Google Gadgets going cross-platform

Google Gadgets going cross-platform

Thursday, November 29, 2007

By Mike Pinkerton, Software EngineerCheck it out for yourself

Use JavaScript, not JScript

WebKit is case-sensitive, JScript is not, which can lead to problems if you assume can you do things like interchange SetTimeOut() and setTimeout().
Avoid JScript-only features like collections and ActiveX.

Avoid IE-specific DOM extensions, just as if you were writing a multi-browser web application.

Avoid Windows-specific APIs

You shouldn't assume ActiveX or certain DLLs are available. Neither WebKit nor Mac OS X supports ActiveX, so these gadgets must be rewritten.
Avoid Windows-only APIs such as Google Talk. These APIs are not (yet) available on Mac OS X.

Understand how Dashboard is different

The Dashboard environment is very different from a web page or the Desktop sidebar on Windows in that it comes and goes as the user activates it. Don't rely on your gadget always being visible. Your gadget won't run or update when Dashboard isn't in the foreground.
Don't rely on access to the file system. The security model for Dashboard doesn't allow arbitrary file access to the hard disk, although your gadget does have access to files in its own archive. Things like file pickers won't work. Note that while restricted file system access is a departure from how gadgets work on Windows, it's consistent with Dashboard's security model and the behavior of other widgets developed for Mac OS X.