before filter in applicatino_controller.

rubyonrails-talk
1

If I do something like this:

class ApplicationController < ActionController::Base   protect_from_forgery   before_filter RubyCAS::Filter   before_filter :fetch_operator   include SessionsHelper

  private

  def fetch_operator     @current_operator ||= session[:cas_user] && Operator.find_by_uid(session[:cas_user])     rescue ActiveRecord::RecordNotFound       redirect_to("/404.html")   end

end

The fetch_operator action is always executed, before every action in every controller? I'd want to fetch the operator only at start and not before every action but I need to have it available on every view and controller.

2

Hi,

The fetch_operator action is always executed, before every action in every controller?

Yes, all kind of filters implemented inside ApplicationController class are always executed in every controller (whose parent is ApplicationController) unless you change the behavior explicitly.

class ApplicationController < ActionController::Base   ...   before_filter :fetch_operator ... end

class anotherController < ApplicationController   before_filter :fetch_operator, :only => [:login] end

For further information, see: http://rails.rubyonrails.org/classes/ActionController/Filters/ClassMethods.html

Exequiel.

3

Are you then using the @current_operator variable in places in your controller? (like "if @current_operator.name == 'fred'..."?)

If so, instead use a helper method to return the operator (and populate it if necessary), rather than the filter method:

class ApplicationController < ActionController::Base   protect_from_forgery   before_filter RubyCAS::Filter   include SessionsHelper   helper_method :current_operator

  def current_operator     @current_operator ||= fetch_operator   end

  private   def fetch_operator     session[:cas_user] && Operator.find_by_uid(session[:cas_user])     rescue ActiveRecord::RecordNotFound       redirect_to("/404.html")   end

end

4

But if I want fetch the operator only once at application startup?

5

But if I want fetch the operator only once at application startup?

I guess you can set up a session variable to make sure to call only once.

if !session[:operator_called]   ...   session[:operator_called] = true end

6

In a method of application controller?

7

It’s just an example, you can add that piece of code in any method, for example:

class ApplicationController < ActionController::Base

…

before_filter :call_operator_once

…

def call_operator_once

if !session[:operator_called]

fetch_operator()

!session[:operator_called] = true

end

end

end

8

Yes but it executes the call_operator before each action of each controller in my application.

9

Typo error, it should be:

def call_operator_once     if !session[:operator_called]       fetch_operator()       session[:operator_called] = true     end end

Right, it will called before each action of each controller in your application, but only one time the fetch_operator method will be executed. I thought you want to make sure that fetch_operator method is executed at least one time independent of controller. Now, if you want to use a filter method and avoid to call it in other controllers you can use "skip_before_filter :my_method" in each controller. And if you definitely don't use this method in other controllers, I guess you don't need define a filter method, just call it as usually in each action that you need it, because any filter that you defined inside the ActionController class will be inherited by other controllers.