This document discusses debugging Drupal with the PHP debugger extension Xdebug. It begins by explaining what Xdebug is and how it communicates with an IDE. It then covers installing Xdebug and configuring php.ini settings. The document contrasts debugging with and without Xdebug, highlighting Xdebug's advantages like stepping through code, inspecting variables, and changing values. It concludes by promoting a live demonstration of debugging basics in PHPStorm like watches and breakpoints.

1. heliocore.com
Frank Carey
CEO - Co-founder
Debugging Drupal with Xdebug
Heliocore
heliocore.com
Frank Carey
CEO - Co-founder
Follow me @frankcarey

2. heliocore.com
Frank Carey
CEO - Co-founder

3. What is XDebug?
● PHP debugger extension available since 2002
● Created by Derick Rethans
● Written in C and Open Source
● Uses DeBuGger protocol (DBGp)
● Starts when your php process starts, and tries
to communicate with port 9000 (default)
● Provides all kinds of goodies we’ll talk about!

4. XDEBUG: Hey, anyone listening on ip address
127.0.0.1 and port 9000? If not, I’m just going to
continue..
IDE: Hey XDEBUG, I’m here so hold on.. I’d like
you to stop at these breakpoints if you get to them.
XDEBUG: OK, I’ll reply back if I hit one of those
breakpoints.
XDEBUG: Hey, IDE I just hit breakpoint 2 and
stopped.. What do you want me to do now? ...
How XDebug communicates

5. 1) Check if already installed (phpinfo())
2) PECL
pecl install xdebug
(OR) HOMEBREW
brew install php56-xdebug
3) Add xdebug module and settings to php.ini*
*The php.ini you have for cli (drush) is often different than
your Apache php.ini
Installing Xdebug

6. You need to know the right ip address to connect to!
Are you running php local or remotely?
Running Local (127.0.0.1) Running remote (192.168.X.1)
XAMP/WAMP etc
Acquia Dev Desktop
OSX native php
Homebrew php
DrupalVM
Vagrant
VirtualBox
Docker
Remote Server

7. Check phpinfo() or php -i | grep xdebug
zend_extension=/.../xdebug.so
xdebug.remote_enable=On
xdebug.remote_host=192.168.99.1
xdebug.remote_autostart=1
xdebug.remote_port=9000
xdebug.idekey="netbeans-xdebug"
xdebug.max_nesting_level=256
Php.ini Xdebug settings

8. heliocore.com
Frank Carey
CEO - Co-founder
Debugging
without Xdebug

9. Debugging Without XDebug
● var_dump(), print_r(), echo()
● drupal_set_message()
● Devel Module:
○ dpm/dsm()
○ drupal_debug()

10. Example dpm() output using Devel module.

11. ● Shooting in the dark / trial and error
● Pollutes screen
● Memory intensive
● Requires altering your code (and remembering
to clean it up)
● dpm() not reliable
● Very limited functionality
○ Can’t pause execution
○ Read only
○ One thread only
Limitations of the Devel approach

12. ● Requires an IDE (that has good support)
● Requires a PHP extension to be installed
● Requires ini settings
● Adds overhead to PHP when installed:
○ Drupal
○ Composer
Limitations of Debugging with XDebug

13. heliocore.com
Frank Carey
CEO - Co-founder
Debugging
WITH Xdebug

14. ● Real-time debugging
○ Stepping through code
○ Inspecting variables
○ Call Stack
● Advanced Breakpoints
● Watches
● Changing Values on the fly!
Features we’ll Demonstrate

15. heliocore.com
Frank Carey
CEO - Co-founder
Setting up
PHPStorm
(DEMO)

16. heliocore.com
Frank Carey
CEO - Co-founder
Watches
(DEMO)

17. heliocore.com
Frank Carey
CEO - Co-founder
Debugging
Basics
(DEMO)

18. heliocore.com
Frank Carey
CEO - Co-founder
Advanced
Breakpoints
(DEMO)

19. THANKS!
Follow me @frankcarey
Check out Ahoy 2.x at: bit.ly/ahoycli