Rails 4 / Sprockets：特定于控制器的JavaScript随处可用？

Question

I'm running a Rails 4.2.4, and when creating a controller auth , app/assets/javascripts/auth.js is automatically created. It tells me that:

// Place all the behaviors and hooks related to the matching controller here. // All this logic will automatically be available in application.js.

That's fine, but since application.js manifest includes a //require_tree . , any file I add in the app/assets/javascripts folder will be available to any controller.

I was under the impression that those files were specific to one controller and wouldn't show up anywhere else but on pages of, say, AuthController .

Am I missing something here or is this by design and simply exists to help organize workflow, but nothing more?

Answer 1

You are right in that for the situation you described, any javascript you put in app/assets/javascripts/auth.js will be available to to any views that use your application.js manifest, not just ones rendered by your AuthController .

This is by design and is perhaps misleading. How to organize javascript within the Rails framework is a bit of a hot-topic regularly debated and without consistent conventions.

The idea of splitting your javascript into a file/directory structure matching the rest of your application code is just a convenience measure to help you know where to look for or place "sprinkles" of javascript. Before Rails 4, view helper modules were in a similar state - their filenames matched respective views and controllers but the methods themselves were available across the entire app (by default).

That said, just because Rails doesn't impose limitations on javascript scopes, doesn't mean you shouldn't follow a convention and manually enforce it. Breaking your application manifest up into multiple controller manifests or putting erb logic inside of your layout can help achieve this.

Like I said, it's a hot-topic so if you do a little Googling on how to organize javascript in Rails you'll find tons of blogs with articulated suggestions. Here's a decent example:

http://brandonhilkert.com/blog/organizing-javascript-in-rails-application-with-turbolinks/