This document provides tips and tricks for debugging WordPress sites. It discusses using developer tools in browsers to inspect elements and network traffic. The document recommends enabling WP_DEBUG and using the Query Monitor plugin to monitor queries, hooks, and request information. It also provides an example PHP fatal error from server logs with the file and line number to help debug issues. The document is intended as an audience participation talk to walk through steps to identify problems, find the cause, and resolve issues when debugging WordPress sites.

1. WordPress Debugging
Tips and Tricks
KEANAN KOPPENHAVER
KEANAN@DOEJO.COM
! @KKOPPENHAVER

3. This is one of those
audience participation
talks.

4. Step 1:
Identify the problem

6. Step 2:
Find the cause

7. Step 3:
Find the solution

8. Step 4:
Repeat

9. Part 1 | Front End

10. What are Dev Tools?

11. (Spoiler Alert: They
help with debugging
step 2)

12. Developer Tools
• Bundled with most major browsers (Chrome,
Firefox, Safari)
• Allow you to inspect elements, console, network
traffic and much more
• You can even code in dev tools (please don’t)

13. Demo:
Chrome Dev Tools

14. Bonus Tip:
Safari Dev Tools work with iOS
simulator

15. Part 2 | Back End

16. if ( $env == ‘development’ ) {
PLEASE USE WP_DEBUG;
(or WP_DEBUG_LOG)
}

17. Query Monitor
• Dev plugin runs in the background on every
page when enabled
• You can monitor much more than queries…
• Hooks, theme info, request info, oh my!

19. Demo:
Query Monitor

20. Let’s talk about
server logs

22. [03-May-2016 21:12:56 UTC] PHP Fatal error: Uncaught Error: Cannot
use object of type stdClass as array in /Users/doejo/code/Dev/
wordpress/wp-content/themes/clientname/lib/admin-helpers.php:303
Stack trace:
#0 /Users/doejo/code/Dev/wordpress/wp-includes/plugin.php(525):
RootsSageExtrasrestrict_adding_tags('')
#1 /Users/doejo/code/Dev/wordpress/wp-settings.php(393):
do_action('init')
#2 /Users/doejo/code/Dev/wordpress/wp-config.php(85):
require_once('/Users/doejo/co...')
#3 /Users/doejo/code/Dev/wordpress/wp-load.php(37):
require_once('/Users/doejo/co...')
#4 /Users/doejo/code/Dev/wordpress/wp-admin/admin.php(31):
require_once('/Users/doejo/co...')
#5 /Users/doejo/code/Dev/wordpress/wp-admin/post.php(12):
require_once('/Users/doejo/co...')
#6 {main}
thrown in /Users/doejo/code/Dev/wordpress/wp-content/themes/
clientname/lib/admin-helpers.php on line 303

23. [03-May-2016 21:12:56 UTC] PHP Fatal error:
Uncaught Error: Cannot use object of type
stdClass as array in /Users/doejo/code/Dev/
wordpress/wp-content/themes/clientname/lib/
admin-helpers.php:303

24. Questions?
KEANAN KOPPENHAVER
KEANAN@DOEJO.COM
! @KKOPPENHAVER