A Bemedianced™ Introduction to Ruby

An introduction for beginner/intermediate/advanced Ruby developers

Transcript

1. A Bemedianced™ Introduction to Ruby Andrea Rossi | @lucidstack
2. Beginner Bemedianced™ (trademark pending)
3. Beginner / Intermediate Bemedianced™ (trademark pending)
4. Bemedianced™ (trademark pending) Beginner / Intermediate/ Advanced
5. WHAT IS RUBY? (trademark pending) Ruby is a dynamic, reflective, object-oriented, general- purpose programming language. It was designed and developed in the mid-1990s by Yukihiro "Matz" Matsumoto in Japan. Bemedianced
6. AN INTERPRETED LANGUAGE Bemedianced
7. AN INTERPRETED LANGUAGE (trademark pending) Bemedianced • Ruby MRI (Matz's Ruby Interpreter)
8. AN INTERPRETED LANGUAGE (trademark pending) • Ruby MRI (Matz's Ruby Interpreter) Bemedianced • JRuby • Rubinius
9. AN INTERPRETED LANGUAGE (trademark pending) Bemedianced JRUBY › rbenv install jruby-9.1.12.0 … › rbenv local jruby-9.1.12.0
10. AN INTERPRETED LANGUAGE (trademark pending) Bemedianced JRUBY require 'java' frame = javax.swing.JFrame.new("Window") # Creating a Java JFrame label = javax.swing.JLabel.new("Hello") # We can transparently call Java methods on Java objects, # just as if they were defined in Ruby. frame.add(label) # Invoking the Java method 'add'. frame.setDefaultCloseOperation(javax.swing.JFrame!::EXIT_ON_CLOSE) frame.pack frame.setVisible(true)
11. AN INTERPRETED LANGUAGE (trademark pending) Bemedianced JRUBY require '!../my-jars/spatial4j.jar' wkt = 'POLYGON((0 0, 10 0, 10 20, 5 -5, 0 20, 0 0))' factory = JtsSpatialContextFactory.new factory.validationRule = ValidationRule.repair_buffer0 ctx = factory.new_spatial_context buffer0 = ctx.readShapeFromWkt(wkt) !!...
12. AN INTERPRETED LANGUAGE (trademark pending) RUBINIUS Bemedianced › rbenv install rbx-3.82 … › rbenv local rbx-3.82
13. AN INTERPRETED LANGUAGE (trademark pending) RUBINIUS Bemedianced Compiled!
14. AN INTERPRETED LANGUAGE (trademark pending) RUBINIUS Bemedianced Real Threads! Compiled!
15. AN INTERPRETED LANGUAGE (trademark pending) RUBINIUS Bemedianced Real Threads! Compiled! C libraries!
16. AN INTERPRETED LANGUAGE (trademark pending) RUBINIUS Bemedianced Real Threads! Compiled! C libraries! Battle-tested?
17. DATA TYPES Bemedianced
18. DATA TYPES (trademark pending) String Boolean Number Array Bemedianced Hash Symbol
19. (trademark pending) BOOLEAN irb(main):0> true !=> true irb(main):0> false !=> false irb(main):0> true !|| false !=> true irb(main):0> true !&& false !=> false irb(main):0> (true !|| true) !|| 1 !== 1 !=> true DATA TYPES Bemedianced
20. (trademark pending) BOOLEAN irb(main):0> (something.present? !&& something.this) !|| "that" !=> "this" DATA TYPES Bemedianced
21. (trademark pending) BOOLEAN irb(main):0> (something.present? !&& something.this) !|| "that" !=> "this" irb(main):0> (something.present? and something.this) or "that" !=> "this" DATA TYPES Bemedianced
22. (trademark pending) STRING irb(main):0> 'this is a string' !=> 'this is a string' irb(main):0> "and so is this" !=> "and so is this" irb(main):0> a_var = 'interpolated' irb(main):0> "this string can be !#{a_var}" !=> "this string can be interpolated" irb(main):0> "a word".upcase !=> "A WORD" irb(main):0> "two" !<< " strings" # this is different !=> "two strings" irb(main):0> "two" + " strings" # from this !=> "two strings" DATA TYPES Bemedianced
23. (trademark pending) DATA TYPES Bemedianced irb(main):0> A_CONSTANT = 'this should stay the same' !=> "this should stay the same" irb(main):0> A_CONSTANT !<< " but it doesn't!" !=> "this should stay the same but it doesn't!" irb(main):0> A_CONSTANT !=> "this should stay the same but it doesn't!" STRING
24. (trademark pending) DATA TYPES Bemedianced irb(main):0> TRY_AGAIN = 'this should stay the same'.freeze !=> "this should stay the same" irb(main):0> TRY_AGAIN !<< " but it doesn't!".freeze RuntimeError: can't modify frozen String from (irb):84 irb(main):0> TRY_AGAIN !=> "this should stay the same" STRING
25. (trademark pending) Benchmark.bm do |x| CONSTANT = "string".freeze var = 'another_string' x.report('freeze') { 10_000_000.times { var !== CONSTANT } } x.report('no_freeze') { 10_000_000.times { var !== 'string' } } x.report('to_sym') { 10_000_000.times { var.to_sym !== :string } } end freeze 0.490000 0.000000 0.490000 ( 0.490177) no_freeze 1.130000 0.000000 1.130000 ( 1.151812) to_sym 1.220000 0.010000 1.230000 ( 1.229188) DATA TYPES Bemedianced STRING
26. (trademark pending) SYMBOL DATA TYPES Bemedianced irb(main):0> :a_symbol !=> :a_symbol irb(main):0> :a_symbol.object_id # never changes !=> 773468 irb(main):0> :a_symbol !== :another_symbol # super fast !=> false
27. (trademark pending) SYMBOL DATA TYPES Bemedianced Do not turn generated strings into symbols ⛔
28. (trademark pending) NUMBER DATA TYPES irb(main):0> 1 + 1 !=> 2 irb(main):0> 0.1 + 0.2 !=> 0.30000000000000004 irb(main):0> _.round(1) !=> 0.3 irb(main):0> "I can interpolate !#{3 + 5}!" !=> "I can interpolate 8!" Bemedianced
29. (trademark pending) ARRAY DATA TYPES irb(main):0> an_array = [1, 2, 3, 4] !=> [1, 2, 3, 4] irb(main):0> an_array !<< 5 !=> [1, 2, 3, 4, 5] irb(main):0> an_array += [6, 7] !=> [1, 2, 3, 4, 5, 6, 7] irb(main):0> an_array.max !=> 7 Bemedianced
30. (trademark pending) ARRAY DATA TYPES irb(main):0> an_array.class !=> Array irb(main):0> an_array.class.ancestors !=> [Array, Enumerable, Object, Kernel, BasicObject] irb(main):0> an_array.each { |num| # do something with num } !=> [1, 2, 3, 4, 5, 6, 7] irb(main):0> an_array.map { |num| num + 1 } !=> [2, 3, 4, 5, 6, 7, 8] irb(main):0> an_array.select { |num| num.odd? } !=> [1, 3, 5, 7] Bemedianced
31. (trademark pending) ARRAY DATA TYPES irb(main):0> final = an_array.each_with_object("The numbers are") do |num, string| irb(main):1> string !<< " !#{num}" irb(main):2> end !=> "The numbers are 1 2 3 4 5 7 8" irb(main):0> final !=> "The numbers are 1 2 3 4 5 7 8" Bemedianced
32. (trademark pending) ARRAY DATA TYPES irb(main):0> duplicates = [] !=> true irb(main):0> duplicates !<< 1 !=> [1] irb(main):0> duplicates !<< 1 !=> [1, 1] irb(main):0> duplicates !<< 2 !=> [1, 1, 2] irb(main):0> duplicates.uniq !=> [1, 2] Bemedianced
33. (trademark pending) ARRAY DATA TYPES irb(main):0> require 'set' !=> true irb(main):0> set = Set.new !=> #<Set: {}> irb(main):0> set !<< 1 !=> #<Set: {1}> irb(main):0> set !<< 1 !=> #<Set: {1}> irb(main):0> set !<< 2 !=> #<Set: {1, 2}> irb(main):0> set.to_a !=> [1, 2] Bemedianced
34. ARRAY DATA TYPES Bemedianced Sets do not care about position ✌ /
35. (trademark pending) HASH DATA TYPES Bemedianced irb(main):0> {"a string" !=> 2} !=> {"a string" !=> 2} irb(main):0> {a_symbol: "a string"} !=> {:a_symbol !=> "a string"} irb(main):0> {a: 2, "b" !=> 2.4} !=> {:a !=> 2, "b" !=> 2.4} irb(main):0> {rand() !=> 24} # anything can be a hash key !=> {0.33565217456135554!=>24}
36. (trademark pending) HASH DATA TYPES Bemedianced irb(main):0> a_hash = {a: 2, b: 4} !=> {a: 2, b: 4} irb(main):0> a_hash[:a] !=> 2 irb(main):0> a_hash.merge({b: 6}) !=> {:a !=> 2, :b !=> 6} irb(main):0> a_hash !=> {:a !=> 2, :b !=> 4}
37. (trademark pending) HASH DATA TYPES irb(main):0> a_hash[:a] = {inner: {super_inner: 4}} !=> {:inner !=> {:super_inner !=> 4}} irb(main):0> a_hash[:a][:inner][:super_inner] !=> 4 irb(main):0> a_hash.dig(:a, :inner, :super_inner) !=> 4 irb(main):0> a_hash[:a] = nil !=> nil irb(main):0> a_hash.dig(:a, :inner, :super_inner) !=> nil Bemedianced Ruby 2.3
38. (trademark pending) HASH DATA TYPES MODIFIERS = { String !=> lambda { |value| value + " (modified)" }, Integer !=> lambda { |value| value + 1 }, Float !=> lambda { |value| value + 0.1 } } ["this", 13, "that", 1.4].map do |value| MODIFIERS[value.class][value] end # ["this (modified)", 14, "that (modified)", 1.5] Bemedianced
39. (trademark pending) HASH DATA TYPES MODIFIERS = { String !=> lambda { |value| value + " (modified)" }, Integer !=> lambda { |value| value + 1 }, Float !=> lambda { |value| value + 0.1 } } ["this", 13, "that", 1.4].map do |value| MODIFIERS[value.class][value] end # ["this (modified)", 14, "that (modified)", 1.5] Bemedianced
40. OOP IN RUBY Bemedianced
41. OOP IN RUBY (trademark pending) Modules Classes Bemedianced
42. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal end my_animal = Animal.new
43. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal def initialize(species) @species = species end end
44. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal def initialize(species) @species = species end end a_doggo = Animal.new("doggo")
45. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal def initialize(species) @species = species end end a_doggo = Animal.new("doggo") a_doggo.species NoMethodError: undefined method `species' for #<Animal:0x007fc9580117f0 @species="doggo">
46. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal def initialize(species) @species = species end def species # a method! @species end end a_doggo = Animal.new("doggo") a_doggo.species !=> "doggo"
47. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal attr_reader :species def initialize(species) @species = species end end a_doggo = Animal.new("doggo") my_class_obj.species !=> "doggo"
48. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal def initialize(species) @species = species end def species=(species) @species = species end end catdog = Animal.new("cat") catdog = "dog" !=> "dog"
49. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal attr_writer :species def initialize(species) @species = species end end catdog = Animal.new("cat") catdog.species = "dog" !=> "dog"
50. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Animal attr_accessor :species def initialize(species) @species = species end end catdog = Animal.new("cat") catdog.species !=> "cat" catdog.species = "dog" !=> "dog"
51. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Doggo < Animal def initialize @species = "doggo" end end a_doggo = Doggo.new a_doggo.species !=> "doggo"
52. OOP IN RUBY (trademark pending) Bemedianced CLASSES class Doggo < Animal def initialize @species = "doggo" end def walk "I'm walking here!" end end a_doggo = Doggo.new a_doggo.walk !=> "I'm walking here!"
53. OOP IN RUBY (trademark pending) Bemedianced MODULES module CanWalk def walk "I'm walking here!" end end
54. OOP IN RUBY (trademark pending) Bemedianced MODULES class Doggo < Animal include CanWalk end a_doggo = Doggo.new a_doggo.walk !=> "I'm walking here!"
55. OOP IN RUBY (trademark pending) CLASSES Bemedianced Ruby supports the Singleton pattern out of the box
56. OOP IN RUBY (trademark pending) CLASSES Bemedianced class Configurator include Singleton attr_accessor :config def initialize @config = YAML.load("initial_config.yml").deep_symbolize_keys end class !<< self def get(key) instance.config[key] end def set(key, value) instance.config[key] = value end end end Configurator.get(:port) !=> 8000
57. Bemedianced OOP IN RUBY CLASSES DelegateClass helps keep your code clean and lean &
58. Bemedianced OOP IN RUBY CLASSES class User < ActiveRecord!::Base devise :token_authenticatable, :database_authenticatable, :registerable, :recoverable, :rememberable, :trackable, :confirmable, :omniauthable include AccountValidation include HasProfiles include HasAvatar include EmailsRecipient include HasDevices include HasServers include HasPlaylists include HasEntitlements include HasFeatures include HasRoles !!...
59. Bemedianced OOP IN RUBY CLASSES class Marketing!::User < DelegateClass(Core!::User) def receives_newsletter? created_at > DateTime.new(2010) end end class Billing!::User < DelegateClass(Core!::User) def restore_purchase PayPal.restore(id) end end user = Core!::User.where(username: "tommywiseau") billing_user = Billing!::User.new(user) billing_user.restore_purchase
60. OOP IN RUBY (trademark pending) MODULES Bemedianced Modules are best friends with functional programming
61. OOP IN RUBY (trademark pending) MODULES Bemedianced module Headers def self.parse(headers) # do stuff to parse the headers end def self.print(headers) print headers end end
62. OOP IN RUBY (trademark pending) MODULES Bemedianced module Headers extend self def parse(headers) # do stuff to parse the headers end def print(headers) print headers end end
63. Bemedianced OOP IN RUBY CLASSES define_method for meta- programming shenanigans )
64. Bemedianced OOP IN RUBY METAPROGRAMMING class RubyMeetup meetup_api = "https:!//api.meetup.com/rsvp/15123523" HTTParty.get(meetup_api)["results"].each do |result| define_method(result["member"]["name"].snakecase) do "!#{result["member"]["name"]} is here!" end end end RubyMeetup.new.andrea_rossi !=> "Andrea Rossi is here!"
65. Bemedianced WEB DEVELOPMENT WITH RUBY
66. WEB DEVELOPMENT IN RUBY (trademark pending) Sinatra Ruby on Rails Bemedianced Grape
67. WEB DEVELOPMENT IN RUBY Bemedianced RUBY ON RAILS Super-rapid development!
68. WEB DEVELOPMENT IN RUBY Bemedianced RUBY ON RAILS Strong conventions! Super-rapid development!
69. WEB DEVELOPMENT IN RUBY Bemedianced RUBY ON RAILS Strong conventions! Super-rapid development! Lots and lots of gems!
70. WEB DEVELOPMENT IN RUBY Bemedianced RUBY ON RAILS Strong conventions! Super-rapid development! Lots and lots of gems! Overkill?
71. WEB DEVELOPMENT IN RUBY Bemedianced RUBY ON RAILS Strong conventions! Super-rapid development! Lots and lots of gems! Overkill? It's not blazingly fast (sorry)
72. WEB DEVELOPMENT IN RUBY SINATRA+GRAPE Much less code involved Bemedianced
73. WEB DEVELOPMENT IN RUBY SINATRA+GRAPE (can be) Blazingly fast Much less code involved Bemedianced
74. WEB DEVELOPMENT IN RUBY SINATRA+GRAPE (can be) Blazingly fast Much less code involved Deeper understanding of the stack Bemedianced
75. WEB DEVELOPMENT IN RUBY SINATRA+GRAPE (can be) Blazingly fast Much less code involved Deeper understanding of the stack A bit of boilerplate is required Bemedianced
76. WEB DEVELOPMENT IN RUBY SINATRA+GRAPE (can be) Blazingly fast Much less code involved Deeper understanding of the stack A bit of boilerplate is required You make the conventions / Bemedianced
77. WEB DEVELOPMENT IN RUBY HEXAGONAL RAILS/SINATRA/GRAPE SEPARATE ALL THE CONCERNS Bemedianced
78. WEB DEVELOPMENT IN RUBY HEXAGONAL RAILS/SINATRA/GRAPE Makes testing so much easier SEPARATE ALL THE CONCERNS Bemedianced
79. WEB DEVELOPMENT IN RUBY HEXAGONAL RAILS/SINATRA/GRAPE Makes testing so much easier SEPARATE ALL THE CONCERNS Much lower maintenance costs Bemedianced
80. WEB DEVELOPMENT IN RUBY HEXAGONAL RAILS/SINATRA/GRAPE Makes testing so much easier SEPARATE ALL THE CONCERNS Much lower maintenance costs Can get over-complicated if not planned Bemedianced
81. WEB DEVELOPMENT IN RUBY HEXAGONAL RAILS/SINATRA/GRAPE Makes testing so much easier SEPARATE ALL THE CONCERNS Much lower maintenance costs Can get over-complicated if not planned Can be a hard sell to management Bemedianced
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