How to add a new file type that will be auto refreshed (run) in Meteor?

I want to define a new file type like .bar and put that kind of files in client folder of Meteor. When I editor and modify a .bar file, Meteor will call a program to scan and processing this .bar file then generates a .js file.

If you’re using webstorm, you can probably setup a custom watcher for this.
If you’re using sublime, there’s a built in build script that you can specify file types to monitor.
If you’re using atom, there’s likely a editor based solution for manually restarting meteor.

If you’re using any other editors, improve!

You should look into the new build process for Meteor 1.2

Edit: Also the wiki: https://github.com/meteor/meteor/wiki/Build-Plugins-API

I am using Atom. When I save a file it can launch a program to execute?

Thanks. That is what I need. Any complete samples such as .jade or .less that I can modify?