Self.included like a constructor method that gets called when a module is included in a class?

Hey all,

Let’s say you have a controller class and you include a module:

class ApplicationController < ActionController::Base
include AuthenticationSystem

def default_page
case
when cu.group_is?(:a) then a_path
when cu.group_is?(:b) then b_path
when cu.group_is?(:c) then c_path
end
end
end

Notice how this method makes a call to method cu. Now in order for cu to
exist, that means the module methods must be copied into
ApplicationController before any of its methods are called by
subclasses:

class DashboardController < ApplicationController
def root
redirect_to default_page
end
end

If the module methods were not included prior to default_page being
called in ApplicationController, since default_page calls method cu
defined in the module AuthenticationSystem, it would throw error.

That part is clear. But what is unclear is what’s the whole purpose of
this:

module AuthenticationSystem
def self.included(base)
base.send :helper_method, :current_user
end
end

If, for example, current_user setter/getter are already declared in
module:

def current_user
@current_user = User.find_by_id(session[:user_id])
end

alias :cu :current_user

def current_user=(new_user)
session[:user_id] = new_user ? new_user.id : nil
@current_user = new_user
end

and thus will be copied into the ApplicationController class, then
what’s the point of sending it to the class using base.send when it will
already be copied into the class?

Or is base.send like a contructor method that gets executed before
anything else in the module and therefore when its included in a class,
it acts as consutrcotr of class and gets called prior to any methods of
the class being called?

Thanks for response.

On May 9, 8:03pm, John M. [email protected] wrote:

Hey all,

Let’s say you have a controller class and you include a module:

module AuthenticationSystem
def self.included(base)
base.send :helper_method, :current_user
end
end

The point of this is to call helper_method :current_user. You can look
up what helper_method does in the rails docs.

Fred

The point of this is to call helper_method :current_user. You can look
up what helper_method does in the rails docs.

Fred

ok so basically this allows you to use current_user in your views.

thanks for response