simple attribute copy

You definitely shouldn't be changing models in the view.

Depending on what you're trying to do, you might be better off putting your attribute copying code in your model, along the lines of:

class ModelA < ActiveRecord::Base
end

class ModelB < ActiveRecord::Base

  def self.create_from_a(model_a)
    # Set this model's attributes from other model's attributes
    save
  end
end

Then in your controller you can call:

class MyController < Application
  def my_action
    @my_a = ModelA.find(params[:id])
    @my_b = ModelB.create_from_a(@my_a)
  end
end

James.