Rails: call another controller action from a controller

I need to call the create action in controller A, from controller B.

The reason is that I need to redirect differently when I'm calling from controller B.

Can it be done in Rails?

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 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.

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)

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.

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.

[Composition][1] 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][1]) 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. [1]: https://en.wikipedia.org/wiki/Object_composition

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

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