You wouldn’t try and work out what’s wrong with your car engine by looking at the front bonnet.. so why debug your application from the outside when you can “pop the hood”? The xDebug extension for PHP offers some amazing tools for developers to both understand and debug problems in their applications, but is frequently passed over as its benefits, setup, and configuration are poorly understood. This talk aims to bring xDebug to the masses, discussing the setup of xDebug for a couple of local environments ( currently Local by FlyWheel, Laravel’s Homestead and Laravel’s Valet, though open to including more ‘WordPress’ environments like chassis ) and the configuration of your IDE ( VS Code / PHPStorm). Along with some demonstrations of how this method of working can help everyone take their development to the next level. Presented by Alex Bishop @aj_adl

1. Debugging
WordPress
With xDebug
Alex James Bishop
@aj-adl

2. Huge thanks to the Organisers
and Sponsors!

3. Using xDebug to profile our
code and pinpoint bottlenecks

4. Using xDebug to debug our
(WordPress) applications

5. Using xDebug to help
develop features

6. Delivering higher-quality
data to you as the developer

7. The Land Before Time
xDebug

8. Late May, the Year 2000…

9. 🎉🎉🎉🎉
🎉

13. V4.0 !!! Now with added programming language!

14. var_dump( $variable );

15. It’s been a little while since
2000…

17. var_dump( $variable );

19. • xDebug offers lots of utility
• xDebug does take some time to setupvar_dump( $variable );
error_log( $variable );

20. Print based debugging

21. Echo / Print based debugging
• Only gives us values for chosen variables
• Doesn’t show us the rest of the current scope
• Captures variables at single point in time

22. To use an analogy..

23. To use an analogy..

24. Step-through debugging
• Stops the execution at a certain (break) point.
• Ability to inspect all variables in current scope
• See current call stack leading to breakpoint
• Advance through the execution to see changes over time

26. Echo based debugging
requires modifying your
code..

27. $would_do = anything_for_love();
//var_dump( $would_do );
if ( $would_do === $that ){
//var_dump(“wont’t do that”);
return false;
}

28. Sometimes we can forget to
remove them too…

32. https://xdebug.org/

33. xDebug can do a lot
• Makes ‘var_dump’ better!
• Code profiling to measure performance
• Step-through debugging using DBGp protocol

34. Profiling with xDebug

35. Check out Otto’s talk at WC EU

36. xdebug.profile_output_dir
Profiling: pro-tip for VM users

37. Remote debugging 💅🏼

38. Getting started
• xDebug extension installed in our development
environment
• xDebug client (standalone or IDE)
• Correct Configuration of both

39. Choose your Pokemon
Local Development Environment

45. Choose your IDE

48. Bonus Tip: Browser Extensions!

50. Help with configuration

51. IDE Configuration

56. Config for both IDEs can be set at a
global and per-project level

57. The remote debugging request flow

58. (or CLI )

59. xdebug.default_enable
xdebug.remote_enable
xdebug.remote_autostart
?XDEBUG_SESSIONS_START={id}
XDEBUG_SESSION cookie

60. xdebug.remote_port
xdebug.remote_host
xdebug.remote_connect_back

61. DBGp request
xdebug.remote_port=9000

62. Hello…. Is it DGBp you’re looking for?

63. DBGp request
Breakpoints

66. Components of an xDebug Client

67. Call Stack

68. Variables

69. Watches

70. Console

71. Debugging Actions

72. The importance of state and
timing

73. Pluging development examples
• WooCommerce (core) & Extensions
• Gravity Forms
• View layers, MVC frameworks etc

74. Should I use xdebug?

75. if( $utility > $implementation ){
use_the_new_thing();
}

76. Detailed setup guides are on
the way

78. Q & A

79. Thank You