This document contains an agenda and slides for a presentation on typing in PHP 7 and Drupal 8. The presentation covers scalar type hinting, return type declarations, type checking modes, and handling type exceptions in PHP 7. It also discusses how Drupal 8 is fully compatible with PHP 7's type system. The presentation aims to show how PHP 7's stronger typing improves code quality and reduces bugs when combined with Drupal 8.

2. JoinusforSprints
First-Time Sprinter Workshop - 9am-12pm in Room 271-273
Mentored Core Sprint - 9am-6pm in Room 275-277
General Sprints - 9am-6pm in Room 278-282
Friday, May 13 at the Convention Center

3. TypedDrupal-AgreatcombinationofD8and
PHP7
Aditya Ghan

4. AdityaGhan(Adi)
SolutionArchitect
aditya.ghan@blisstering.com
@AdityaGhan

5. Agenda
✤ Typing as a concept
✤ Categories of Type Systems
✤ Type Hinting in PHP
✤ Non Scalar Type Hinting
✤ Type Juggling.

6. Agenda
✤ Scalar Type Hinting in PHP7
✤ Return Type Declarations in PHP7
✤ Type Checking Modes
✤ Handling Type Exceptions
✤ D8 and PHP7

7. Typingasaconcept

8. Typingasaconcept
Giving data types to
❖ Variable Declarations
❖ Parameters of a function
❖ Return value of a function
❖ Expressions

9. CategoriesofTypeSystems

10. TypeSystems- Categories
✤ Strong (Java, Python)
✤ Weak (PHP, Perl)
✤ Static (C#, Java)
✤ Dynamic (PHP, Python)

11. Categories(TypeSystems)
Strongly Typed language
Strongly typed language is more likely to generate an error or refuse to
compile if type checking fails.
A Weakly typed language may produce unpredictable results or may
perform implicit type conversion in case of type conflict.
Weakly Typed Language

12. Typing-Categories
Statically Typed language
A statically typed language checks the type system at compile time.
A dynamically typed language interprets the type of a variable at runtime
Dynamically Typed Language

13. Strong
Static Dynamic
Weak

14. TypeHintinginPHP

15. TypeHintinginPHP
Type Hinting allows you to specify the type of
data which a method is expecting.

16. Parameter type which the method is expecting
PHP 5.x

17. NonScalarTypeHinting

18. NonScalarTypeHinting
Type hinting for complex data types.
Objects (Since PHP 5.0), Array (Since PHP 5.1),
Callable (Since PHP 5.4)

19. Output: Array([0]=>1[1]=>2)
PHP 5.x

20. PHPCatchable fatalerror: Argument1passedto
adi_function()mustbeaninstanceofint,integergiven
PHP 5.x

21. TypeJuggling

22. TypeJuggling
Type Juggling is a feature (or design
flaw, according to where you stand on
typing) where we convert a variable
type to the most appropriate type
according to the action performed. It
can lead to an unexpected output.

23. Output: FirstislessthanSecond
PHP 5.x

24. Output: SecondislessthanFirst
PHP 5.x

25. PHP 5.x
Output: Pleasepassintegerinputs

26. EnterPHP7!

27. ScalarTypeHintinginPHP7

28. ScalarTypeHintinginPHP7
RFC introduced last year:
https://wiki.php.net/rfc/scalar_type_hints_v5
Extends type hints for scalar types.
Scalar Types – integer, float, string and boolean

29. Output: 1
PHP 7

30. PHPCatchable fatalerror: Argument1passedto
adi_function()mustbeaninstanceofint,integergiven
PHP 5.x

31. Output: UncaughtTypeError:Argument1passedto
adi_function()mustbeofthetypeinteger,stringgiven
PHP 7

32. Output: UncaughtTypeError:Argument2passedto
compare_function()mustbeofthetypeinteger,stringgiven
PHP 7

33. ScalarTypeHinting-Benefits

34. Benefits:
✤ Less Bugs (Especially the ones
which are Hard to debug)
✤ Code Readability
✤ Concrete function definition.

35. ReturnTypeDeclarationsinPHP7

36. ReturnTypeDeclarations
In PHP7, we could specify the data type of the return value
of a function. This is great!
Adding Return Type Declarations facilitates a nice contract
where the caller is sure that the called function would return
a value with type as promised

37. Output: 1
ReturnTypeDeclaration
PHP 7

38. Output: Returnvalueofadi_function()mustbeofthetype
integer,stringreturned
PHP 7

39. ReturnTypeDeclarationfeatures:
✤ Contract between caller and callable function.
✤ No error handling required in the caller function.
✤ Function definitions are more readable.

40. AndFinally!!

41. NoMoreisset’sand!empty’s!

42. TypeCheckingModes

43. WeakMode
Weak Mode checks the parameter
types and return types in a weak
fashion for a file. It will perform Type
juggling for matching the type of the
parameter to the passed value.

44. Output: 1
PHP 7

45. Output: UncaughtTypeError:Argument1passedto
adi_function()mustbeofthetypeinteger,stringgiven
PHP 7

46. StrictMode
Strict Mode checks the parameter
types and return types in a strict
fashion for a file.

47. Output: UncaughtTypeError:Argument1passedto
adi_function()mustbeofthetypeinteger,stringgiven
PHP 7

48. Output: 1
PHP 7

49. Importantpointstonote:
✤ Return Type Declarations are optional, even in the
strict mode.
✤ The only type conversion allowed is int to float, i:e
Float parameter type can accept a integer value.
✤ NULL is still allowed as a default value for a
function parameter.

50. Output: 10
PHP 7

51. Rememberthis?WhiteScreenofDeath(WSOD)PHP7EngineExceptionsarehappytohelp!

52. HandlingTypeExceptions

53. PHP 7
Output: Bro,Somethingwentwrong,pleasepassproperinputs

54. “Hey, What about Drupal? Isn’t this Drupalcon? ”
~ Abraham Lincoln

56. Drupal8andPHP7
Drupal 8 has a 100% pass on PHP7.
https://www.drupal.org/node/3060/qa

57. Let’sseea“Typed”D8module

58. DrupalconNewOrleans
drupalcon-new-orleans
Sluggify!

59. AnyQuestions?
ForModuleCode:
https://github.com/aghan/typed_drupal

60. SoHowWasIt?-TellUsWhatYouThink
Evaluate this session -
https://events.drupal.org/neworleans2016/schedule/2016-05-10
AdityaGhan–aditya.ghan@blisstering.com

61. AdityaGhan(Adi)
Email:aditya.ghan@blisstering.com
Twitter:@AdityaGhan
Thankyou!