RubyOffRails - January 2014 Office Hours

class-beginner.rb

class Automobile

  @@autos = []

  def self.count
    @@autos.count
  end

  def self.autos_for_model(model_name)
    @@autos.select{|auto| auto.model == model_name}
  end

  def self.search(args)

    # model: honda
    # color: red

    results = args.map do |key, value|
      @@autoss.select!{|auto| auto.send(key) == value.to_sym}
    end

    ## We have an array of arrays, which will keep a red toyota since red matches
    ## only keep autos if they are in every result
    results.flatten.uniq.select do |auto| 
      results.all?{|result| result.include? auto}
    end
  end

  def self.register(automobile)
    @@autos << automobile
  end
  
  attr_accessor :model, :color

  def initialize(args)
    @model = args.fetch(:model)
    @color = args.fetch(:color)
    Automobile.register(self)
  end

  def self.search(args)
    Automobile.search(args)
  end
end


Automobile.new model: :mazda, color: :red
Automobile.new model: :toyota, color: :red
Automobile.new model: :honda, color: :red
Automobile.new model: :mazda, color: :blue

puts Automobile.search("color"=> "red").inspect

class-final.rb

### We ended up with a global singleton object, AutomobileRecords
### I like to think of this as a database, really.

require 'singleton'

class AutomobileRecords
  include Singleton

  attr_reader :autos

  def initialize
    @autos = []
  end

  def count
    autos.count
  end

  def autos_for_model(model_name)
    autos.select{|auto| auto.model == model_name}
  end

  def search(args)

    results = autos
    args.each do |key, value|
      results.select!{|auto| auto.send(key) == value.to_sym}
    end
    results

  end

  def register(automobile)
    autos << automobile
  end

end

class Automobile
  attr_accessor :model, :color

  def initialize(args)
    @model = args.fetch(:model)
    @color = args.fetch(:color)
    AutomobileRecords.instance.register(self)
  end

  def self.search(args)
    AutomobileRecords.instance.search(args)
  end
end


Automobile.new model: :mazda, color: :red
Automobile.new model: :toyota, color: :red
Automobile.new model: :honda, color: :red
Automobile.new model: :mazda, color: :blue

puts Automobile.search("color"=> "red").inspect

puts AutomobileRecords.instance == AutomobileRecords.instance

class-middle.rb

class Automobile

  @@autos = []

  def self.count
    @@autos.count
  end

  def self.autos_for_model(model_name)
    @@autos.select{|auto| auto.model == model_name}
  end

  def self.search(args)

    # model: honda
    # color: red

    results = @@autos
    args.each do |key, value|
      results.select!{|auto| auto.send(key) == value.to_sym}
    end
    results
  end

  def self.register(automobile)
    @@autos << automobile
  end
  
  attr_accessor :model, :color

  def initialize(args)
    @model = args.fetch(:model)
    @color = args.fetch(:color)
    Automobile.register(self)
  end

  def self.search(args)
    Automobile.search(args)
  end
end


Automobile.new model: :mazda, color: :red
Automobile.new model: :toyota, color: :red
Automobile.new model: :honda, color: :red
Automobile.new model: :mazda, color: :blue

puts Automobile.search("color"=> "red", model: :toyota).inspect