# in your Gemfile gem "filter_object" # in your controller class YourController < ApplicationController before_filter YourFilterClass.new end # inside app/filters/your_filter_class.rb class YourFilterClass include FilterObject::Filter def filter(controller) super # your filter logic starts here... end end
What's a Filter Object?
A filter object is a nice way to remove logic from your controller. Usually you start implementing simple filter methods, like these
class YourController < ApplicationController before_filter :your_filter_method # your actions... private def your_filter_method # some simple logic here... end end
and everything is fine. As the time passes you start to add more code to the
your_filter_method filter method. It will look like shit after some time...
Sometimes the problem already starts too complicated for a single method.
Rails already provides a way to fix this kind of problem. You can do something like this:
class YourController < ApplicationController before_filter FilterClass # your actions... end class FilterClass def self.filter(controller) # your complex filter logic goes here... end end
and it will work. Only that now you are creating a lot of class methods, which are hard to test. Also, it's hard to keep state inside your filter. The nice thing is that you can easily pass anything that responds to
filter to the before_filter and after_filter calls. So why not pass an instance?
class YourController < ApplicationController before_filter FilterClass.new # your actions... end class FilterClass def filter(controller) # your complex filter logic goes here... end end
Ok, now this is real OO! It will much easier to write your tests, too. But you'll need to handle methods delegation to the controller, things like calling
render, and so on.
This is where filter_object comes in.
class FilterClass include FilterObject::Filter def filter(controller) super # so filter_object can set the delegations if params[:programming_is] != "cool" # the call to params will be automatically redirected to the controller redirect_to program_more_path end end end
Now you can call controller methods directly inside your filter objects and they will be properly delegated to the controller.
Methods that will be automatically delegated to the controller
If you are using a controller method that is not listed here, please send a pull request!
Why a gem for such a simple and stupid code?
Because I was repeating this thing all over my projects, so I got tired.
This project is released under The MIT License
Copyright © 2012, Cássio Marques
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