From: Pat Eyler <pate@...>
Date: 2001-09-05T04:15:50+09:00
Subject: [ruby-talk:20885] Re: newbie question

On 05 Sep 2001 03:48:48 +0900, Ned Konz wrote:
> On Tuesday 04 September 2001 11:18 am, Pat Eyler wrote:
> > I never did translate:
> >
> > public class Movie {
> >     public static final int CHILDREN = 2;
> >     public static final int REGULAR = 0;
> >     public static final int NEW_RELEASE = 1;
> > }
> >
> > into ruby, instead I just used the magic numbers 0, 1, and 2 as needed
> > in methods of other classes and ignored it figuring I would have a
> > blinding flash of the obvious and go back and fix things.  As can be
> > expected, the blinding flash never came.
> >
> > Would someone mind enlightening me?
> 
> class Movie
>    CHILDREN = 2
>    REGULAR = 0
>    NEW_RELEASE = 1
>    # ...
> end

I'd tried this, but it fails when I try to use the values outside a
Movie (see the class Price hierarchy) in the code below.  This probably
means that I'm doing something else wrong...

-----------------------------------------------------------------------

class Movie
  CHILDRENS = 2
  NEW_RELEASE = 1
  REGULAR = 0

  attr_accessor :title, :pricecode

  def initialize(title,pricecode)
    @title = title
    setPriceCode(pricecode)
    @pricecode = getPriceCode
  end

  def getPriceCode
    @price.getPriceCode
  end

  def setPriceCode(pricecode)
    case pricecode
      when REGULAR
        @price = RegularPrice.new

      when NEW_RELEASE
        @price = NewReleasePrice.new

      when CHILDRENS
        @price = ChildrensPrice.new

    end
  end

  def getCharge(daysRented)
    @price.getCharge(daysRented)
  end

  def getFrequentRenterPoints(daysRented)
    @price.getFrequentRenterPoints(daysRented)
  end


end

class Rental
  attr_accessor :aMovie, :daysRented
  
  def initialize(aMovie, daysRented)
    @aMovie, @daysRented = aMovie, daysRented
  end

  def getCharge
    aMovie.getCharge(daysRented)
  end

  def getFrequentRenterPoints
    aMovie.getFrequentRenterPoints(daysRented)
  end

end

class Customer
  attr_accessor :name

  def initialize(name)
    @name = name
    @rentals = Array.new
  end

  def addRental(aRental)
    @rentals.push(aRental)
  end

  def statement
    result = "\nRental Record for #{@name}\n"
    @rentals.each do
      |each| 
      # show figures for this rental
      result +="\t#{each.aMovie.title}\t#{each.getCharge}\n"
    end
    result += "Amount owed is #{getTotalCharge}\n"
    result += "You earned #{getFrequentRenterPoints} frequent renter points"
  end

  def htmlStatement
    result = "\n<H1>Rentals for <EM>#{name}</EM></H1><P>\n"
    @rentals.each do
      |each|
      result += "#{each.aMovie.title}: #{each.getCharge}<BR>\n"
    end
    result += "You owe <EM>#{getTotalCharge}</EM><P>\n"
    result += "On this rental you earned <EM>#{getFrequentRenterPoints}" +
      "</EM> frequent renter points<P>"
  end

  def getTotalCharge
    result = 0.0
    @rentals.each do
      |each|
      result += each.getCharge()
    end
    result
  end

  def getFrequentRenterPoints
    result = 0
    @rentals.each do
      |each|
      result += each.getFrequentRenterPoints
    end
    result
  end

end

class Price
  def getPrice
  end

  def getCharge(daysRented)
  end

  def getFrequentRenterPoints(daysRented)
    1
  end
end

class ChildrensPrice < Price
  def getPriceCode
    Movie.CHILDRENS
  end

  def getCharge(daysRented)
    result = 1.5
    if daysRented > 3
      result += (daysRented - 3) * 1.5
    end
  end
end

class NewReleasePrice < Price
  def getPriceCode
    Movie.NEW_RELEASE
  end

  def getCharge(daysRented)
    daysRented * 3.0
  end

  def getFrequentRenterPoints(daysRented)
    frequentRenterPoints = 1
    # add bonus for a two day new release rental
    if ( daysRented > 1) 
      frequentRenterPoints += 1
    end
    frequentRenterPoints

  end 
end

class RegularPrice < Price
  def getPriceCode
    Movie.REGULAR
  end

  def getCharge(daysRented)
    result = 2.0
    if (daysRented > 2)
      result += (daysRented -2) * 1.5
    end
    return result
  end
end   

-------------------------------------------------------------------------


thanks,
-pate

> 
> -- 
> Ned Konz
> currently: Stanwood, WA
> email:     ned@bike-nomad.com
> homepage:  http://bike-nomad.com