Rails: How to access the current controller in Observer?

Question

I need to access the current controller or send a notification from the observer method.

class SomeObserver < ActiveRecord::Observer
    observe :some_model
    cattr_accessor :current_controller

    def after_create(record)
        ...
        current_controller.flash[:notice] = "Some message!"
    end
end

class ApplicationController < ActionController::Base
    before_filter do
        SomeObserver.current_controller = self
    end
    ...
end

Answer 1

As others have stated, access to the controller from an observer somewhat violates the MVC principle. Also, these answers correspond to your specific use case.

But , if you need a more general solution, you can try to customize the way the Rails Blenders are .

Sweepers are ordinary observers, but they provide access to the controller if the observer is called from the controller.

- , , , (.. Singleton)

, :

• , .

• singleton around_filter :

  class ApplicationController < ActionController::Base
    around_filter MyObserver.instance #, only: [...]
  end
  

• :

  attr_accessor :controller
  
  def before(controller)
    self.controller = controller
    true #Don't forget this!
  end
  
  def after(controller)
    self.controller = nil
  end
  

. controller nil, .

Answer 2

Observer MVC. , MVC, - flash[:notice] SomeModel.create().

Answer 3

? , , .

application_helper, - diplays.

def show_flash
[:notice, :error, :warning].collect do |key|
  content_tag(:div, flash[key], :id => key, :class => "flash flash_#{key}") unless   flash[key].blank?
end.join
end

<% show_flash %>

, , - , , , .

flash[:notice] = "Some message!"

Answer 4

There is no connection between observers and controllers in Rails, and I'm afraid that you will not achieve your goal in the standard way. However, I suggest using threads to achieve this.