Presented at WordCamp Birmingham, August 2019.

1. WORDPRESS DEVELOPMENT
IN A MODERN PHP WORLD
DREW JAYNES

2. DREW JAYNES
SANDHILLS DEVELOPMENT

3. THIS TALK:
WHY VS HOW

4. THIS TALK
TALK STRUCTURE
▸ Basic benefits of each concept
▸ Why each is worth pursuing
▸ Pseudo-code examples
▸ Practical examples

5. Slides: http://drewf.us/wpyall19

6. WHAT DOES MODERN PHP
DEVELOPMENT REALLY MEAN?

7. POWERFUL

8. WHAT DOES MODERN PHP DEVELOPMENT MEAN?
MODERN PHP CONCEPTS
▸ Namespaces
▸ Autoloading
▸ Closures (anonymous functions)
▸ *Type hints (and return type
declarations)
▸ Late static binding
▸ Traits
▸ Generators
▸ Group aliasing
▸ *Exception-based error
handling
▸ libsodium and modern security

9. MODERN DOESN’T JUST
MEAN NEWER FEATURES

10. FOLLOW THE LEADER?

11. “AS FOR THE FUTURE, YOUR TASK IS
NOT TO FORESEE IT, BUT TO ENABLE IT."
Antoine De Saint-Exupéry
WORDPRESS DEVELOPMENT IN A MODERN PHP WORLD

12. Slides: http://drewf.us/wpyall19

13. THE CONCEPTS

14. REFACTORING
OLD CODE

15. BEST PRACTICES
REFACTORING APPROACHES
▸ All or nothing
▸ Rewrite
▸ Back-compat concerns
▸ Gradual iteration
▸ Partial activation
▸ Version-protected bootstrap

16. REFACTORING FOR THE
SAKE OF REFACTORING:
Proceed with Caution

17. NAVIGATING NEW
SKILLS TAKES TIME

18. DO: DIVE IN
HEAD FIRST

19. DON’T: JAM UP
YOUR USERS

20. EMBRACE WHAT YOUR USERS
CAN (VS SHOULD) SUPPORT

21. NAMESPACES

22. BEST PRACTICES
NAMESPACES
▸ Establishes baseline code ownership
▸ Simpler naming of allthethings
▸ Better code segregation
▸ Easier interoperability with other people’s code

23. NAMESPACES
EXAMPLES
▸ My_Verbose_Plugin_Class_Name
▸ My_PluginClass_Name
▸ My_PluginComponentClass_Name
▸ My_Pluginfunction_name()
▸ ThisTotallyWorksEvenThoughItIsRidiculous

24. NAMESPACES
IN PRACTICE: BEFORE

25. NAMESPACES
IN PRACTICE: AFTER

26. WHY USE
NAMESPACES?

27. POWERFUL

28. BEST PRACTICES
WHY USE NAMESPACES?
▸ Prevent naming collisions
▸ Code readability
▸ Promote better code organization
▸ Aliasing can help marry legacy with modern code

29. WITH GREAT ALIASING POWER
COMES GREAT RESPONSIBILITY

30. NAMESPACES
ALIASING EXAMPLES
▸ use Legacy_Verbose_Controller_Class as Standardized_Controller;
class Controller extends Standardized_Controller {}
▸ class_alias( ‘Legacy_Controller_Class’, ‘ComponentStandardized_Controller’ );
new ComponentStandardized_Controller( $collection );

31. NAMESPACES
ALIASING EXAMPLES
▸ use Legacy_Verbose_Controller_Class as Standardized_Controller;
class Controller extends Standardized_Controller {}
▸ class_alias( ‘Legacy_Controller_Class’, ‘ComponentStandardized_Controller’ );
new ComponentStandardized_Controller( $collection );

32. NAMESPACES
ALIASING IN PRACTICE: BEFORE

33. NAMESPACES
ALIASING IN PRACTICE: AFTER

34. NAMESPACES
ALIASING IN PRACTICE: AFTER

35. AUTOLOADING WHAT YOU
NEED WHEN YOU NEED IT

36. BEST PRACTICES
AUTOLOADING
▸ Automatic loading of classes etc. instead of manually requiring them
▸ Typically follows project organization
▸ Composer vs PSR-0 vs PSR-4 vs Rolling your own

37. AUTOLOADERS CONVERT
CLASS NAMES
INTO FILE NAMES

38. BEST PRACTICES
WHY USE NAMESPACES WITH AN AUTOLOADER?
▸ ComponentSub_ComponentFile
▸ Component -> Sub_Component -> File.php

39. POWERFUL

40. AUTOLOADING
AUTOLOADING IN PRACTICE

41. AUTOLOADING
RESOURCES
▸ Composer: https://getcomposer.org/
▸ PSR-0: https://www.php-fig.org/psr/psr-0/
▸ PSR-4: https://www.php-fig.org/psr/psr-4/
▸ Drew’s autoloader: https://gist.github.com/DrewAPicture/
b0f1c0e637b072a41e5dfec6a38a7808
▸ Tom McFarlin’s autoloader: https://github.com/tommcfarlin/simple-
autoloader-for-wordpress

42. HINTING AT MISTAKES
BEFORE YOU MAKE THEM

43. WORDPRESS DEVELOPMENT IN A MODERN PHP WORLD
TYPE HINTS
▸ Helps catch avoidable mistakes
▸ Defines expectations for what is accepted
▸ *Base support for class/interface name or self
▸ 5.1 added array, 5.4 added callable
▸ 7.0 added scalar type support,
e.g. string, bool, int, float (no aliases!)
▸ 7.1 added iterable, 7.2 added object
▸ Multiple types not supported

44. TYPE HINTS
EXAMPLES
▸ function feed_pet( Pet $pet )
▸ ex_update_collection( Collection $collection, array $atts );
▸ try {} catch( Marker_Interface $exception ) {}

45. TYPE HINTS
IN PRACTICE

46. TYPE HINTS
IN PRACTICE

47. NICE TO HAVES

48. AVOID RUNNING OVER YOUR USERS
IN THE PURSUIT OF SHINY THINGS

49. NICE TO HAVES
CLOSURES (5.3+)
▸ Anonymous functions
▸ One way to express simple one-time-use code
▸ Be careful using closures with hooks

50. CLOSURES
PANDORA’S ANONYMOUS BOX
▸ add_action( ‘some_hook’, function( $param1, $param2 ) {
// do stuff
}
▸ function feed_pet( callable $process ) {}
▸ feed_pet( function() {
echo ‘Pet is fed.’;
} );
▸ call_user_func_array( $callback, $args );

51. CLOSURES
PANDORA’S ANONYMOUS BOX
▸ add_action( ‘some_hook’, function( $param1, $param2 ) {
// do stuff
}
▸ function feed_pet( callable $message ) {}
▸ feed_pet( function() {
echo ‘My pet has been fed.’;
} );
▸ call_user_func_array( $callback, $args );

52. CLOSURES
PANDORA’S ANONYMOUS BOX
▸ add_action( ‘some_hook’, function( $param1, $param2 ) {
// do stuff
}
▸ function feed_pet( callable $process ) {}
▸ feed_pet( function() {
echo ‘Pet is fed.’;
} );
▸ call_user_func_array( $callback, $args );

53. CLOSURES
IN PRACTICE

54. CLOSURES
IN PRACTICE

55. CLOSURES CAN BE HANDY, BUT
SHOULD BE USED WITH CARE

56. FLIPPING OOP
ON ITS HEAD

57. NICE TO HAVES
LATE STATIC BINDING (5.3+)
▸ Allows parent/super classes to statically reference aspects
of the calling or sub-class
▸ Flips the OOP inheritance model on its head
▸ Leveraged via the static keyword vs self

58. LATE STATIC BINDING
EXAMPLES

59. LATE STATIC BINDING
EXAMPLES

60. RECYCLING CODE

61. NICE TO HAVES
TRAITS (5.4+)
▸ Makes reusing code across classes simpler
▸ Free of inheritance (horizontal use)
▸ Traits vs dependency injection
▸ Really powerful when combined with abstract methods
▸ Are traits really evil? (no)

62. TRAITS
IN PRACTICE: BEFORE

63. TRAITS
IN PRACTICE: BEFORE

64. TRAITS
IN PRACTICE: AFTER

65. EFFICIENT ALIASING

66. NICE TO HAVES
GROUP ALIASING (7+)
▸ Allows for aliasing multiple classes or functions at once
▸ Cuts down on top-heavy aliasing blocks
▸ Importing and aliasing functions, importing constants was added in 5.6

67. GROUP ALIASING
EXAMPLES

68. GROUP ALIASING
IN PRACTICE

69. BACK-COMPAT
GOTCHAS

70. GOTCHAS
BACK-IN-COMPAT TO LOOK OUT FOR
▸ Call-time pass by reference (warning 5.3, fatal 5.4)
▸ my_update_function( &$something ) // WRONG
▸ PHP4-style constructors deprecated (7.0+)
▸ Static calls to non-static methods (deprecated 7.0+)

71. “SOFTWARE IS A GREAT COMBINATION
BETWEEN ARTISTRY AND ENGINEERING.”
Bill Gates
WORDPRESS DEVELOPMENT IN A MODERN PHP WORLD

72. THANK YOU
Drew Jaynes (DrewAPicture)
Slides: http://drewf.us/wpyall19