My helper methods in controller

Question

My app should render html, to answer when a user clicks ajax-link. My controller: ``` def create_user @user = User.new(params) if @user.save status = 'success' link = link_to_profile(@user) #it's my custom helper in Application_Helper.rb else status = 'error' link = nil end render :json => {:status => status, :link => link} end ``` My helper: ``` def link_to_profile(user) link = link_to(user.login, {:controller => "users", :action => "profile", :id => user.login}, :class => "profile-link") return(image_tag("/images/users/profile.png") + " " + link) end ``` I have tried such methods: ``` ApplicationController.helpers.link_to_profile(@user) # It raises: NoMethodError (undefined method `url_for' for nil:NilClass) ``` and: ``` class Helper include Singleton include ActionView::Helpers::TextHelper include ActionView::Helpers::UrlHelper include ApplicationHelper end def help Helper.instance end help.link_to_profile(@user) # It also raises: NoMethodError (undefined method `url_for' for nil:N…

Accepted Answer

Oki. Let's recap. You want access to certaint functions/methods, but you don't want those methods to be attached to current object.

So you want to make a proxy object, that will proxy/delegate to those methods.

```
class Helper
  class << self
   #include Singleton - no need to do this, class objects are singletons
   include ApplicationHelper
   include ActionView::Helpers::TextHelper
   include ActionView::Helpers::UrlHelper
   include ApplicationHelper
  end
end
```

And, in controller:

```
class UserController < ApplicationController
  def your_method
    Helper.link_to_profile
  end
end
```

The main disadvantage to this approach is that from the helper functions you won't have access to controller context (EG you won't have access to params, session, etc)

A compromise would be to declare those functions as private in the helper module, therefore, when you will include the module, they will also be private in the controller class.

```
module ApplicationHelper
  private
  def link_to_profile
  end
end

class UserController < ApplicationController
  include ApplicationHelper
end
```

, as Damien pointed out.

Update: The reason why you get the 'url_for' error is that you do not have access to controller's context, as stated above. You could force passing the controller as a parameter(Java-style ;) ) like:

```
Helper.link_to_profile(user, :controller => self)
```

and then, in your helper:

```
def link_to_profile(user, options)
  options[:controller].url_for(...)
end
```

or event a bigger hack, presented here. However, i would reccomend the solution with making methods private and including them in the controller.

My helper methods in controller

Solution

Problem