Guidelines for calling controller methods in helper modules?

Question

Few questions:

1. Is it possible to call a controller method in a helper module (e.g., application helper)?

2. If so, how does the helper handle the rendering of views? Ignore it?

3. In what instances would you want to call a controller method from a helper? Is it bad practice?

4. Do you have any sample code where you're calling controller methods in helper?

Answer 1

You generally don't call controller-methods from helpers. That is: if you mean a method that collects data and then renders a view (any other method that needs to be called should probably not be in a controller). It is definitely bad practice and breaks MVC.

It is, however, perfectly possible to make controller-methods available in the views, a great example is for instance the current_user method.

To make a controller method available in the views, as a helper method, just do

private

def current_user
  # do something sensible here
  @current_user ||= session[:user] 
end
helper_method :current_user

Such a method is best defined in the private section, or it could be available as an action (if you a wildcard in your routing).

Answer 2

Declare your methods on the corresponding controller

private
def method_name1
...
end

def method_name2
...
end

In the head of the controller declare

helper_method :method_name1, :method_name2

You may want to declare those methods under private state

And that's it, now you can use your method on a helper