Question

I’m using Rails 3 and mongoid.

I want to save, or update, a value in one record based off of a value in another record.

For example:

class User
  include Mongoid::Document
  field :account_level, :type => Integer
end


class Profile
  include Mongoid::Document
  field :position, :type => Integer
end

If the account_level in User is 1 then position in Profile should be updated to 1 also. If account_level is 2, thenposition` should be 2.

This should be done programmatically without input from the user or using an invisible input field on the client (there must be a better way to do it than that).

Extra question…what is I had the following logic (for position), how would I do this?

account_level 1 = position 1
account_level 2 = position 1
account_level 3 = position 5

Answer 1

Not sure if I understood your question.

Try with callbacks ( http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html ):

For example, in User class:

before_save :set_equals_account_level_and_position
def set_equals_account_level_and_position
  profile.position = account_level
  profile.save!
end