Moving logic from controller to model in rails 3?

Question

I've been building a contest application, and I can easily tell I've been putting wayyyy too much logic in the controller. How can I go about switch this type of logic to the model? (whats important here isn't the logic itself - its far from finished - I'm just trying to understand how to move it out of the controller).

Controller:

def create
    @person = Person.new(params[:person])
    @yournum = rand(100)
    @day = Day.find_by_id(1)
    @prereg = Prereg.find_by_email(@person.email)

    if @preg != nil
      @person.last_name = @prereg.name
    end 

    if @day.number == 1


      if @yournum <= 25
      @person.prize_id = 2
      elsif @yournum > 25 && @yournum <=50
      @person.prize_id = 1
      elsif @yournum > 51 && @yournum <=75
      @person.prize_id = 3
      elsif @yournum > 76 && @yournum <=100
      @person.prize_id = 4
      end

    elsif @day.number == 2

      if @yournum <= 25
      @person.prize_id = 2
      elsif @yournum > 25 && @yournum <=50
      @person.prize_id = 1
      elsif @yournum > 51 && @yournum <=75
      @person.prize_id = 3
      elsif @yournum > 76 && @yournum <=100
      @person.prize_id = 4
      end

    elsif @day.number == 3      

      if @yournum <= 50
      @person.prize_id = 2
      elsif @yournum > 51 && @yournum <=90
      @person.prize_id = 1
      elsif @yournum > 91 && @yournum <= 95
      @person.prize_id = 3
      elsif @yournum > 96 && @yournum <=100
      @person.prize_id = 4
      end

    end

    @person.save
    redirect_to @person

  end

Model:

class Person < ActiveRecord::Base
  belongs_to :prize

end

Thanks!

Elliot

Answer 1

Indeed, that's a pretty ugly controller. As you say, the solution is easy: move all the logic to the model:

def create
  @person = Person.new(params[:person])
  @person.set_price

  if @person.save
    redirect_to @person
  else
    flash[:error] = ...
    render :action => 'new'
  end
end

class Person
  def set_price
    # your logic here
  end
end    

Note that:

1. Controller: you need to check if @person was actually saved (maybe some validation failed).
2. Model: If a person has always to be assigned a price on creation, then use a callback (before_validation, for example). Otherwise, call it from the controller as shown the code above.

Answer 2

class PersonsController < ApplicationController
  respond_to :html
  def create
    @person = Person.new(params[:person])

    if @person.save
      respond_with @person
    else
      flash[:error] = 'Render error'
      render :action => :new
    end
  end
end

class Person
  before_create :method_name

  def method_name
    #Put whatever you want to happen before creation here
  end
end