Question

I have a user registration where a user sets his username, first_class and some other attribs. Now, there are also some other attributes that i have to set, like :str or :acc.

These attributes would probably be set in a mass assignment command like create. I would not want to do something like update_attribute on each one separately of course. Therefore, i have to make them attr_accessible.

However, i don’t want the user to set them. For instance, if the user decides to have a first_class = ‘Ranger’, i would set his :str and and not him.

My idea is that i would just save params[:first_class] or params[:username] and just explicitly set everything else in my create method for the user. Is that how you would do it ?

Answer 1

I’m guessing that the other attributes are pre-determined based on what the user selects as part of the registration process?

In that case, I’d add a before_create hook to your model that calculates and assigns those attributes accordingly:

class PlayerCharacter < ActiveRecord::Base
  before_create :assign_attributes

  # ...

  # This is called after you call "update_attributes" but before 
  # the record is persisted in the database
  def assign_attributes

    # Stats are determined by the 'first_class' attribute
    stats = case first_class
      when "Ranger"  then { :str => 20, :dex => 19, :wis => 8 }
      when "Wizard"  then { :str => 10, :dex => 14, :wis => 18 }
    end

    self.attributes.merge!(stats)
  end
end