Introduction to Moose for wellington.pm

1. use Moose;
&focus_on_actual_problem_solving
Raf Gemmail
@fiqus
Wellington.pm
June 2014

2. % perldoc perltoot

3. % perldoc perltoot

4. % perldoc perltoot

5. % perldoc perltoot

6. % perldoc perltoot
Does Not Solve
A
Business
Problem

7. Class::Accessor

8. Class::Accessor

9. Prelude
● Declarative
● Focus TDD(esign) and Single Responsibility
● Standard Paradigm (Mo[ou].* and Perl6)
● Focus on returning business value / solution

10. Moose

11. Moose
● strict and warnings pragmas enabled

12. Moose
● strict and warnings pragmas enabled
● Constructor : Person->new

13. Moose
● strict and warnings pragmas enabled
● Constructor : Person->new

14. Moose
● strict and warnings pragmas enabled
● Constructor : Person->new({name=>'Raf'})

15. Moose
● strict and warnings pragmas enabled
● Constructor : Person->new({name=>'Raf'})
● $person->name() immutable
● $person->age(5)
● $age = $person->age()

16. Moose
● strict and warnings pragmas enabled
● Constructor : Person->new
● get_name, get_age, set_age

17. Moose
● strict and warnings pragmas enabled
● Constructor : Person->new
● get_name (immutable), get_age, set_age
● Type checking (isa)

18. Attributes

19. Attributes
● is (mutability)

20. Attributes
● is (mutability)
– ro
– rw

21. Attributes
● is (mutability)
● isa (type validation)

22. Attributes
● is (mutability)
● isa (type validation)
– Class (or Role) name eg. Person

23. Attributes
● is (mutability)
● isa (type validation)
– Class (or Role) name eg. Person
– Object, Int, Str, Bool, Undef, Def,

24. Attributes
● is (mutability)
● isa (type validation)
– Class (or Role) name eg. Person
– Object, Int, Str, Bool, Undef, Def,
– Ref (ScalarRef, ArrayRef, HashRef)

25. Attributes
● default
– default => $scalar || $sub_ref

26. Attributes
● default
– default => $scalar || $sub_ref

27. Attributes
● builder, lazy
– builder => method name

28. Attributes
● builder, lazy
– builder => method name

29. Attributes
● lazy_build => 1

30. Attributes
● handles
– Proxies methods

31. Attributes

32. Attributes

33. Attributes

34. Attributes
● reader, writer
– reader => 'get_vm_config'
– writer => 'persist_vm_config'

35. Attributes
● reader, writer
– reader => 'get_vm_config'
– writer => 'persist_vm_config'
● clearer => 'clear_attribute_name'

36. Attributes
● reader, writer
– reader => 'get_vm_config'
– writer => 'persist_vm_config'
● clearer => 'clear_attribute_name'
● predicate => 'is_verbose'

37. Attributes
● reader, writer
– reader => 'get_vm_config'
– writer => 'persist_vm_config'
● clearer => 'clear_attribute_name'
● predicate => 'is_verbose'
● trigger => &sub_ref

38. Inheritance
● extends
Ape
Person

39. Method Resolution Order
Animal
RomulanHorse Bird
Pegasus
• Perl depth-first: [Pegasus → Horse → Animal, Bird]
• eg. Animal::brain has higher precedence than Bird::brain
• C3 MRO breadth first: [Pegasus, Horse, Bird, Animal]
use base qw(Horse Bird)
vs
extends qw(Horse Bird);

40. Roles
● Cross cutting characteristics (attribs &
methods)
● Like Interface and Abstract Classes
● Base class which defines a behavioural
contract with an optional partial implementation

41. Roles

42. Role

43. Roles

44. Roles

45. Roles
Consume role
after attribute
declarations

46. Method Modifiers
● Aspects – non-core cross-cutting behaviour
● Advice (do this) eg. A sub ref
● Point-cut (do the advice at these point of my
execution) Before, After and Around

47. Method Modifiers
● Aspects – non-core cross-cutting behaviour
● Advice (do this) eg. A sub ref
● Point-cut (do the advice at these point of my
execution) Before, After and Around

48. Method Modifiers

49. Method Modifiers

50. Method Modifiers

51. Method Modifiers

52. Method Modifiers

53. Method Modifiers

54. Method Modifiers
before

55. Method Modifiers
Transform
Args

56. Method Modifiers
Real
Method

57. Method Modifiers
After
Invocation

58. Method Modifiers

59. Method Modifiers
● around [qw(method_1, method_2)]
● before qr/.*all_matching.*/
● HasLogger HasModel HasWebService

60. MooseX::Method::Signatures
MooseX::Method::Signatures
● Type checking
● Method argument validation

61. Moops

62. MooseX::Declare

63. And they all play together

64. Avoid Starup Costs with Moo
● Pure Perl

65. Avoid Starup Costs with Moo
● Pure Perl
● Painless integration with Moose deps (auto
upgrades and does meta-magic)

66. Avoid Starup Costs with Moo
● Pure Perl
● Painless integration with Moose deps (auto
upgrades and does meta-magic)
● Fast

67. MooseX
● Lots of Extensions
● MooseX::Types
● MooseX::GetOpt
● MooseX::App
● MooseX::Aspect

68. MooseX::App::Simple

69. MooseX::App::Simple

70. Meta Magic
● Refelection
● __PACKAGE__->meta
– > get_all_subclasses
– > get_all_attributes
– > add_attribute
– > magix

71. Recommendations
● use namespace::clean
● Use MooseX::FollowPBP
● Test::Routine – test with fixture roles and
various permutations of test data.
● __PACKAGE__->meta->make_immutable;

72. no Moose;