Rails: call another controller action from a controller

You can use a redirect to that action :

redirect_to your_controller_action_url

More on : Rails Guide

To just render the new action :

redirect_to your_controller_action_url and return

The logic you present is not MVC, then not Rails, compatible.

• A controller renders a view or redirect

• A method executes code

From these considerations, I advise you to create methods in your controller and call them from your action.

Example:

 def index
get_variable
end


private


def get_variable
@var = Var.all
end

That said you can do exactly the same through different controllers and summon a method from controller A while you are in controller B.

Vocabulary is extremely important that's why I insist much.

Perhaps the logic could be extracted into a helper? helpers are available to all classes and don't transfer control. You could check within it, perhaps for controller name, to see how it was called.

This is bad practice to call another controller action.

You should

1. duplicate this action in your controller B, or
2. wrap it as a model method, that will be shared to all controllers, or
3. you can extend this action in controller A.

My opinion:

1. First approach is not DRY but it is still better than calling for another action.
2. Second approach is good and flexible.

3. Third approach is what I used to do often. So I'll show little example.

   def create
   @my_obj = MyModel.new(params[:my_model])
   if @my_obj.save
   redirect_to params[:redirect_to] || some_default_path
   end
   end
   

So you can send to this action redirect_to param, which can be any path you want.

Separate these functions from controllers and put them into model file. Then include the model file in your controller.

You can use url_for to get the URL for a controller and action and then use redirect_to to go to that URL.

redirect_to url_for(:controller => :controller_name, :action => :action_name)

To use one controller from another, do this:

def action_that_calls_one_from_another_controller
controller_you_want = ControllerYouWant.new
controller_you_want.request = request
controller_you_want.response = response
controller_you_want.action_you_want
end

You can call another action inside a action as follows:

redirect_to action: 'action_name'

class MyController < ApplicationController
def action1
redirect_to action: 'action2'
end


def action2
end
end

Composition to the rescue!

Given the reason, rather than invoking actions across controllers one should design controllers to seperate shared and custom parts of the code. This will help to avoid both - code duplication and breaking MVC pattern.

Although that can be done in a number of ways, using concerns (composition) is a good practice.

# controllers/a_controller.rb
class AController < ApplicationController
include Createable


private def redirect_url
'one/url'
end
end


# controllers/b_controller.rb
class BController < ApplicationController
include Createable


private def redirect_url
'another/url'
end
end


# controllers/concerns/createable.rb
module Createable
def create
do_usefull_things
redirect_to redirect_url
end
end

Hope that helps.