Question

I’m using Rails 3.2.9. When I add CoffeeScript code to a .js.coffee file in the /app/assets/javascripts directory, I get the resulting JavaScript in all of my webpages. The problem is all the JavaScript is wrapped in:

(function() {
  // my code
}).call(this);

So any methods I define are not visible in any other CoffeeScript code I write in other files. What’s the proper way to write a set of reusable CoffeeScript classes and methods with Rails?

Answer 1

The simplest thing to do is to namespace all your classes. If your application is called “app” then in your initialization code before anything else happens:

// Set up the namespace.
window.app = { }

and then in all your .coffee files:

class app.Pancakes
    #...

Then you’d have a global namespace and you’d reference everything through that namespace:

pancakes = new app.Pancakes

Similarly for simple functions:

app.where_is = (pancakes, house) -> ...

# And elsewhere...
x = app.where_is(...)

There are various ways of setting up and partially hiding the namespace but they’re all variations on the above and simple namespacing plays nicely with the Rails asset pipeline.