IanWhitney

Ruby OOD Reading List

Books

• Refactoring
• Refactoring Ruby Edition
• Refacoring in Ruby Workbook
• Eloquent Ruby
• Ruby Science
• Domain Driven Design
• Free DDD pdf

IanWhitney

#!/usr/bin/env ruby

puts "This is the house that Jack built."
puts ""
puts "This is the malt that lay in the house that Jack built."
puts ""
puts "This is the rat that ate the malt that lay in the house that Jack built."
puts ""
puts "This is the cat that killed the rat that ate the malt that lay in the house that Jack built."
puts ""

IanWhitney

x = Hash.new{|h,k| h[k] = []}

IanWhitney

@athlete = Athlete.find(4329615)
@active_progs = @athlete.future_complete_academic_program_memberships.all(:conditions => "prog_status in ('AC', 'CM')")
@old_progs = @athlete.future_complete_academic_program_memberships.all(:conditions => "prog_status not in ('AC', 'CM')", :order => "action_dt desc")
@academic_tree_paths = @athlete.future_academic_tree_paths

prog = @active_progs.first

@academic_tree_paths.detect { |tp| tp.ps_acad_prog_stdnt_car_nbr == prog.stdnt_car_nbr && tp.ps_acad_prog_acad_career == prog.acad_career}

IanWhitney

# Array of an openstruct works as you'd expect, but to_a does not.  
# OpenStruct descends from Object, Kernel, BasicObject. None of which implement to_a. So that explains that.
# I'm a little unclear on why Array(os) is working. Array(Object.new) works, and OpenStruct descends directly from Object.
# BUT, the Array docs say that it calls .to_ary or .to_a on the argument, and an OpenStruct instance responds to neither of those.
# So....?
require 'ostruct'
#=> true
os = OpenStruct.new
#=> #<OpenStruct>
os.prop1 = "test"

IanWhitney

GIT
  remote: git://github.com/rails/rails.git
  revision: 5d543c5996da986ba8d979cd83236e130a3bd953
  tag: v4.2.0.rc1
  specs:
    actionmailer (4.2.0.rc1)
      actionpack (= 4.2.0.rc1)
      actionview (= 4.2.0.rc1)
      activejob (= 4.2.0.rc1)
      mail (~> 2.5, >= 2.5.4)

IanWhitney

class Bob
  def reply_to(statement)
    statement.reply(self)
  rescue
    default_reply
  end

  def reply_to_silence
    "Fine. Be that way!"
  end

IanWhitney

# From the docs of Kernel.array
#   First tries to call to_ary on arg, then to_a.
#   http://ruby-doc.org/core-2.2.3/Kernel.html#method-i-Array

# Ok, so does a struct respond to to_ary?

Monkey = Struct.new(:name, :favorite_color)
m = Monkey.new("George", "Yellow")
m.respond_to?(:to_ary)
#=> false

IanWhitney

receipt_id = _your_receipt_id_
r = Etl::Receipt.find(receipt_id)
r.audits.each do |a|
  Etl::Audit::Facet.all_classes.each do |f|
    f.where(etl_audit_id: a.id).delete_all
  end
end

s = Etl::Service.new(r)
s.extract_facets

IanWhitney

[1,2,3][3]
#=> nil
# Ask for element outside of the array, get nil. cool.

[1,2,3][3,1]
#=> []
#=> Ask for a 1-element slice that starts outside of the array, get an empty array. Ok?

[1,2,3][4]
#=> nil