Armando Fox armandofox

I teach software engineering and CS pedagogy at UC Berkeley.

armandofox / association1.rb

Created July 8, 2021 23:31

association1.rb

	# it would be nice if we could do this:
	inception = Movie.where(:title => 'Inception')
	alice,bob = Moviegoer.find(alice_id, bob_id)
	# alice likes Inception, bob less so
	alice_review = Review.new(:potatoes => 4)
	bob_review = Review.new(:potatoes => 3)
	# a movie has many reviews:
	inception.reviews = [alice_review, bob_review]
	# a moviegoer has many reviews:
	alice.reviews << alice_review

armandofox / application.html.erb

Created July 8, 2021 23:31

application.html.erb

	<!DOCTYPE html>
	<html>
	<head>
	<title> RottenPotatoes! </title>
	<link rel="stylesheet" href="https://getbootstrap.com/docs/4.0/dist/css/bootstrap.min.css">
	<%= javascript_include_tag :application %>
	<%= csrf_meta_tags %>
	</head>
	<body>
	<div class="container">

armandofox / association1.rb

Created July 8, 2021 23:31

association1.rb

	# it would be nice if we could do this:
	inception = Movie.where(:title => 'Inception')
	alice,bob = Moviegoer.find(alice_id, bob_id)
	# alice likes Inception, bob less so
	alice_review = Review.new(:potatoes => 4)
	bob_review = Review.new(:potatoes => 3)
	# a movie has many reviews:
	inception.reviews = [alice_review, bob_review]
	# a moviegoer has many reviews:
	alice.reviews << alice_review

armandofox / topmovies.rb

Created May 11, 2021 16:39

topmovies.rb

	class MoviesController < ApplicationController
	def index
	@movies = Movie.all
	@top_5 = Movie.joins(:reviews).group('movie_id').
	order("AVG(potatoes) DESC").limit(5)
	end
	end

armandofox / topmovies.html.erb

Created May 11, 2021 16:39

topmovies.html.erb

	<!-- a cacheable partial for top movies -->
	<%- cache('top_moviegoers') do %>
	<ul id="topmovies">
	<%- @top_5.each do \|movie\| %>
	<li> <%= movie.name %> </li>
	<% end %>
	</ul>
	<% end %>

armandofox / srp_example.rb

Created May 11, 2021 16:39

srp_example.rb

	class Moviegoer
	attr_accessor :name, :street, :phone_number, :zipcode
	validates :phone_number, # ...
	validates :zipcode, # ...
	def format_phone_number ; ... ; end
	def check_zipcode ; ... ; end
	def format_address(street, phone_number, zipcode) # data clump
	# do formatting, calling format_phone_number and check_zipcode
	end
	end

armandofox / null_object_fix.rb

Created May 11, 2021 16:39

null_object_fix.rb

	class Config
	def self.emailer
	if email_disabled? then NullMailer else
	if has_amiko? then Amiko else MailerMonkey end
	end
	end
	end
	class NullMailer
	def initialize ; end
	def send_email_to(*args) ; true ; end

armandofox / lsp_square_rect_fix.rb

Created May 11, 2021 16:39

lsp_square_rect_fix.rb

	# LSP-compliant solution: replace inheritance with delegation
	# Ruby's duck typing still lets you use a square in most places where
	# rectangle would be used - but no longer a subclass in LSP sense.
	class Square
	attr_accessor :rect
	def initialize(side, top_left)
	@rect = Rectangle.new(side, side, top_left)
	end
	def area ; rect.area ; end
	def perimeter ; rect.perimeter ; end

armandofox / lsp_square_rect.rb

Created May 11, 2021 16:39

lsp_square_rect.rb

	class Rectangle
	attr_accessor :width, :height, :top_left
	def initialize(width,height,top_left) ... ; end
	def area ... ; end
	def perimeter ... ; end
	end
	# A square is just a special case of rectangle...right?
	class Square < Rectangle
	# ooops...a square has to have width and height equal
	attr_reader :width, :height, :side

armandofox / dip_example_3.rb

Created May 11, 2021 16:39

dip_example_3.rb

	class AmikoAdapter
	def initialize ; @mailer = Amiko.new(...) ; end
	def send_email
	@mailer.authenticate(...)
	@mailer.send_message(...)
	end
	end
	# Change the controller method to use the adapter:
	def advertise_discount_for_movie
	moviegoers = Moviegoer.interested_in params[:movie_id]