Leveraging typing features of PHP7 to create awesome Drupal 8 code.

2. Join us for sprints at the Convocation Center tomorrow

3. Typed Drupal - A great
combination of D8 and PHP7
Aditya Ghan

4. Aditya Ghan
Solution Architect
DrupalCon LA 2015
DrupalCon Asia 2016
DrupalCon New Orleans 2016
aditya.ghan@iksula.com

5. Typing as a concept

6. Giving data types to:
Variable Declarations
Parameters of a function
Return value of a function
Expressions

7. Variable Declaration
Function Parameters and Return values

8. Categories of Type Systems

9. Type Systems - Categories
Strong (Java, Python)
Weak (PHP, Perl)
Static (C#, Java)
Dynamic (PHP, Python)

10. Strong
Static Dynamic
Weak

11. Type Hinting in PHP

12. Type hinting in PHP
“Type Hinting in PHP allows you to specify the type of data which a
method is expecting”

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

14. Non-Scalar Type Hinting

15. Non-Scalar Type Hinting
“Type Hinting for Complex data types”
Objects (Since PHP 5.0), Array (Since PHP 5.1), Callable (Since PHP
5.4)

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

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

18. Type Juggling

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

20. Output: FirstislessthanSecond
PHP 5.x

21. Output: SecondislessthanFirst
PHP 5.x

22. PHP 5.x
Output: Pleasepassintegerinputs

23. Let’s Recap!

24. Recap
Typing as a concept
Categories of Type Systems
Type Hinting in PHP
Non-Scalar Type hinting
Type Juggling

25. Enter PHP7!

26. Scalar Type Hinting in PHP7

27. Scalar Type Hinting in PHP7
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

28. Output: 1
PHP 7

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

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

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

32. Return Type Declarations in PHP7

33. Return Type Declarations
In PHP7, we could specify the datatype 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

34. Output: 1
ReturnTypeDeclaration
PHP 7

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

36. Return Type Declarations - Features
Contract between Caller and Callable function.
No Error handling required in the caller function.
Function definitions are more readable.

37. Scalar Type Hinting - Benefits

38. Scalar Type Hinting - Benefits
Less Bugs
Self - Documented Code!
Static Analyzers and IDE may spot mistakes before execution!
Less Unit Tests

39. And Finally!

40. No More isset’s and !empty’s !

41. Type Checking Modes

42. Weak Mode

43. Output: 1
PHP 7

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

45. Strict Mode

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

47. Output: 1
PHP 7

48. Important points to note -
Return Type Declarations are optional, even in the strict mode.
The only type conversions allowed is int to float, i:e Float parameter
type can accept an integer value.
NULL is still allowed as a default value for a function parameter.

49. Output: 10
PHP 7

50. When to use Strict Mode?
“Everywhere except getting inputs from a user in your
application”

51. Remember this?White Screen of Death (WSOD)PHP7 Engine Exceptions are happy to help!

52. Handling Type Exceptions

53. PHP 7
Output: Bro,Somethingwentwrong,pleasepassproperinputs

55. Drupal 8 and PHP7
Drupal 8.2 has a 100% pass on PHP7.
https://www.drupal.org/node/3060/qa
D7 Progress here - https://www.drupal.org/node/2656548

56. Let’s see a “Typed” D8 module

57. Drupal Camp Mumbai
drupal-camp-mumbai
Sluggify

58. Aditya Ghan
Email: aditya.ghan@iksula.com
Thank you!

59. Any Questions?
For Module Code: https://github.com/aghan/typed_drupal