Ruby Idioms

Transcript

1. RUBY & RUBY ON RAILS IDIOMS
2. A word on style
3. - Soft tabs, two space indent - Lines shorter than 80 characters - No spaces after [( and before )] - Methods: snake_case - Classes/Modules: CamelCase - Constants: SCREAMING_SNAKE_CASE - Space after commas: foo(a, b)
4. “Idioms”
5. if answer == 42 # ... elsif foo == 'foo' # ... else # ... end
6. if answer == 42 then # ... elsif foo == 'foo' then # ... else # ... end
7. if answer == 42 then # ... elsif foo == 'foo' then # ... else # ... end
8. if !correct # ... end
9. unless correct # ... end
10. unless correct # ... else # ... end
11. unless correct single_line_of_something end
12. single_line_of_something unless correct single_line_of_something if correct
13. message = if correct "You are right!" else "Sorry, that's wrong." end
14. if !flaky_value.nil? # ... end
15. if flaky_value # ... end
16. if env == :production or env == :development # ... end
17. if [:production, :development].include?(env) # ... end
18. String(123)
19. 123.to_s
20. 123.is_a? String
21. 123.respond_to? :to_s
22. def destroy_universe # ... end destroy_universe def destroy_planet(planet) # ... end destroy_planet(:mars)
23. destroy_universe()
24. def foo(arg1, arg2) # ... end foo 1, 2
25. def foo(options, &block) # ... end foo {}
26. def green? # ... end def destroy! # ... end
27. def foo(name, options) # ... end foo('bar', {:something => 'else', :answer => 42}) foo('bar', :something => 'else', :answer => 42)
28. def foo # ... body return results end
29. def foo(arg) return unless arg == 42 # ... body end
30. a, b = b, a
31. a, b = [1, 2, 3]
32. %w(helsinki oulu tampere) # => ["helsinki", "oulu", "tampere"]
33. %i(helsinki oulu tampere) # => [:helsinki, :oulu, :tampere]
34. %i|helsinki oulu tampere| %i-helsinki oulu tampere-
35. the_number ||= complex_calculation
36. list = [] dictionary = {}
37. class Store class << self def advanced_search # ... end end end
38. Struct.new("Point", :x, :y)
39. class Point < Struct.new(:x, :y) end origin = Point.new(0,0)
40. Point = Struct.new(:x, :y) do def to_s "[#{x}, #{y}]" end end Point.new(0,0).to_s # => "[0, 0]"
41. class Parent @@class_var = "parent" def self.print_class_var puts @@class_var end end class Child < Parent @@class_var = "child" end Parent.print_class_var # => "child"
42. upcase_chars = [] %w(a b c).each do |char| upcase_chars << char.upcase end Not so great
43. %w(a b c).map do |char| char.upcase end Better
44. %w(a b c).map { |char| char.upcase } Even better
45. %w(a b c).map(&:upcase) Great
46. Brand.first.stores.map(&:id) Brand.first.store_ids @active_brands.ids
47. def make_it_bigga(string) string.upcase end %w(a b c).map(&method(:make_it_bigga))
48. [1, 2, nil, 4].compact.reject(&:odd?).inject(&:+) # => 6
49. {:foo => "bar", :baz => 42}.each do |key, value| puts "#{key}: #{value}" end # foo: bar # baz: 42 # => {:foo=>"bar", :baz=>42}
50. [[:foo, "bar"], [:baz, 42]].each do |(key, value)| puts "#{key}: #{value}" end # foo: bar # baz: 42 # => {:foo=>"bar", :baz=>42}
51. [[:foo, "bar"], [:baz, 42]].each do |(_, value)| puts value end # bar # 42 # => [[:foo, "bar"], [:baz, 42]]
52. name == "" name.length == 0 name.empty?
53. count == 0 count.zero?
54. dangerous rescue nil
55. FOLLOW YOUR