For the longest time, developers have asked for application.rb to be renamed to application_controller.rb. This is finally fixed in RailsEdge, and there's even a Death of Application.rb blog posting about it.
That's great, but none of this affects me. Why? Because ApplicationController always annoyed me, so I killed it.
Life without ApplicationController
You might ask, "how do you survive without this loving, parental figure; the ApplicationController?" Because my parent is ActionController::Base, in the same way that most of your models inherit from ActiveRecord::Base. Can you tell me why your models don't inherit from an arbitrary ApplicationRecord class?
The primary reason why a developer puts code into ApplicationController is for code reuse and changing default behavior. The ultimate result is that this class becomes a dumping ground for any common methods required across two or more controllers. Ruby has a better pattern for reusing methods and changing behavior across classes: Modules.
I create my own controller modules in the lib folder, and include them into ActionController::Base. If I want only certain controllers to be affected, the module defines a class level method, similar to the before_filter and has_many macros. For example, some controllers require a login. Rather than adding a filter to ApplicationController, I would make a 'require_login' module. My controllers could optionally use it like this:
1 | class PostController < ActionController::Base |
Why do I go through all this trouble? Because it (1) cuts one layer out of the inheritance tree, and (2) forces me to think about packaging functionality into small, testable modules. I encourage you to look at the code in your ApplicationController, and question whether any or all of your controllers should be inheriting from it.
