Rails - How to move calculation from view to controller

Question

Fairly new to RoR and wondering how I might move this one line of code out of my view and into my controller. I am also using devise and a current user is logged in. Thanks in advance

profile.html.erb

 <%= @profile.calorie / 4  %>

Ive set up a method called calculate within my profiles_controller.rb like so

 helper_method :calculate

 def calculate 
  ..... 
 end

Personally I wouldn't care for such a simple calculation in a view, unless you are using it in more than one place. Creating helper for this seems like an overkill. — BroiSatse
– BroiSatse, Commented Feb 10, 2014 at 20:11
So how might I translate that in a controller without a helper method? — Samuel
– Samuel, Commented Feb 10, 2014 at 20:15
@ssosina - Don't. It is fine to keep little calculations like that in a view. It is much better than creating new instance variable or method. — BroiSatse
– BroiSatse, Commented Feb 10, 2014 at 20:37

miahabdu · Accepted Answer · 2014-02-10 20:19:15Z

1

Just put the calculation in an instance variable in your controller and call it in your view:

<%= @new_calorie  %>

And in your controller action:

def show #or index
   @new_calorie = @profile.calorie / 4
end

answered Feb 10, 2014 at 20:19

miahabdu

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2 Comments

miahabdu Over a year ago

It's because you haven't chosen a record of the object yet. If you just call Profile you're only calling the class, and not any individual records. You'll have to do something like Profile.find(id: params[:id]).calorie / 4 in order to find the calorie of a particular Profile record.

Samuel Over a year ago

Did @calorie = current_user.profile.calorie as i'm using devise. This worked. Thanks for your help

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