Slides from Damien McKenna's session "What to do when things go wrong with Drupal" from Drupalcamp Atlanta 2012.

1. What to do when things go wrong.
(because it will)

2. .. with
CODE!

3. .. and
Freddie Mercury!

4. Damien McKenna
Lead Drupal Architect
@DamienMcKenna
drupal.org/user/108450

5. “Freddie Mercury”
Farrokh Bulsara
Lead vocals
Queen

6. Drupal, Day 1

7. Building with Drupal
• Starting off..
• Lots of trepidation
• Infamous learning curve
• Lots of reading – books, blogs, tutorials..
• Lots of screencasts!

8. Building with Drupal
• Add Views & other modules
• Add a little theming
• Go a long way!

9. Building more with Drupal
• Start feeling comfortable
• Add some more modules
• Build lots of sites!

10. o/
“We Are The Champions”
“News of the World” (1977)
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

11. Continuing on..
• Install a module
• Awesome!

12. But then..
Notice: Undefined index: option in
theme_select_or_other_none() (line 249
of
/sites/all/modules/contrib/select_or_other/
select_or_other.module).
• Whaaa?

13. Eek!
• Line 249:
• Whaaaaaaaaaaaaaaaa?

14. That moment..
“Going Slightly Mad”
“Innuendo” (1977)
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

15. Drupalburp, noun;
• A bug.
• A small bug.
• It’s still a bug.
• There are lots of them.

16. Step 1: Search issue queue
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

17. Step 1: Results
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

18. Step 1: Review
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

19. Step 2: Create a new issue!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

20. Step 2: Create a new issue..
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

21. Step 2: Issue created!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

22. Time to debug!

23. Development Tips
1. drupal_set_message()

24. Whaaaa?
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

25. Development Tips
1. drupal_set_message()
2. debug()

26. debug() output
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

27. Development Tips
1. drupal_set_message()
2. debug()
3. Devel module
4. dpm()

28. dpm()
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

29. dpm() output
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

30. dpm() output awesomesauce!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

31. Reviewing the error
• “Undefined index”
• Means that an array element doesn’t exist.
• I can fix that!

32. Original code
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

33. The fix
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

34. It works!
• Time to share the joy!

35. Get the code
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

36. Getting the code
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

37. Clone it!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

38. Fix it!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

39. Diff it!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

40. Diff it!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

41. Patch it!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

42. Name it!
• Patch naming: project name & issue number.
• [project]-n[issue]-[comment#].patch
• [project]-n[issue]-[comment#]-
[message].patch
– drupal-n1067120-145-d7.patch
– metatag-n1820374.patch
– views-n1809862-7.patch

43. Upload it!
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

44. And then..
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

45. Wait.
• Maintainers can take time to respond.
• People live busy lives.
– Drupal 8’s “development babies” list :-)
• Other modules or core work may take a
higher priority.
• Don’t give up if little or no response.

46. Development Tips
1. drupal_set_message()
2. debug()
3. Devel module
4. dpm()
5. Track your patches!

47. PATCHES.txt
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

48. Development Tips
1. drupal_set_message()
2. debug()
3. Devel module
4. dpm()
5. Track your patches!
6. kpr() and exit()

49. kpr()
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

50. Development Tips
1. drupal_set_message()
2. debug()
3. Devel module
4. dpm()
5. Track your patches!
6. kpr() and exit()
7. xdebug – hardcore debugging!
• .. and IDE debugger or MacGDBp

51. MacGDBp
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

52. Development Tips
1. drupal_set_message()
2. debug()
3. Devel module
4. dpm()
5. Track your patches!
6. kpr() and exit()
7. xdebug – hardcore debugging!
• .. and IDE debugger or MacGDBp
8. Let modules die!

53. Redundant: see redundant
“Who Wants to Live Forever?”
“A Kind of Magic” (1986)
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

54. Abandon obsolete modules
• Focus effort on fewer solutions.
• More focus effort = better modules.
• How many gallery systems do we need?

55. What’s next?

56. Contribute
• You depend upon Drupal for your future.
• Drupal’s future depends upon you!

57. Investments
• Invest minimum of 10% of income for
retirement
• Invest 10% of your week to Drupal

58. Time it
• 10% of 40 hour week
• 4 hours per week
• Friday evening!

59. Companies can do more
• Have a large team?
• Dedicated team contributor
• Organize code sprints
• & fly in experts

60. Why?
• Learn more
• Make your sites better
• Make Drupal better
• Everyone benefits!

61. More info
• Novice issues
• Examine code of small
modules you use
• Click to edit Master text styles
• Poke around with dpm()
– Second level
& kpr()
– Third level
• Read issue queues • Fourth level
– Fifth level
• Contribute!
• http://webchick.net/emb
race-the-chaos

62. Drupal’s future is up to us!
“The Show Must Go On”
“Innuendo” (1977)
• Click to edit Master text styles
– Second level
– Third level
• Fourth level
– Fifth level

63. Thank you

64. Mediacurrent helps organizations architect custom websites by
leveraging our proven processes and deep expertise in Drupal.
@mediacurrent mediacurrent.com