The document discusses clean code practices such as using meaningful names, small and focused functions, and avoiding null values and duplicate code. It also discusses bad code smells like no separation of concerns. The presenter advocates for refactoring, code reviews, and using tools like PHPLOC and PHPCodeSniffer to maintain clean code. He welcomes questions and feedback on topics like WTF as a metric, comments, and error handling best practices.

1. Good code, Bad code
June 2013 @phplx by Jose da Silva

2. Agenda
● WTF as a Metric
● Clean Code
● Bad Code Smells
● Meaningful Names and Formatting
● Comments
● Functions
● Error Handling
● Your time :)

3. About me
Jose da Silva
● VP of Engineering @ GuestCentric
● Doing good and bad PHP since PHP 3 (1999)
● Zend Certified Engineer + Certified Scrum Master
● Open Source
○ Slimframework.com contributor
● Hobbies
○ Table tennis player for more than 20 y
Twitter: josedasilva
Linkedin: linkedin.com/in/josedasilva
Email: josedasilva@gmail.com

4. WTF as a metric

5. How many WTF are enough ?

6. WTF of the day

7. How to fix the WTF issue ?
The developer's only amendment to fix the WTF problem
1. Complain less
+
2. Fix the code
+
3. Remove the unneeded WTF

8. Clean Code
What's clean code anyway ?

9. Clean Code
What's clean code anyway ?

10. Clean Code
What's clean code anyway ?

11. Clean Code
What's clean code anyway ?

12. Clean Code
What's clean code anyway ?
Formatted , Organized and Easy to read/modify

13. Clean Code
Advantages

14. Clean Code
Advantages
● Readable
● Understandable
● Less errors
● Easy to maintain ( fix, modify, learn, support)
● Testable

15. Clean Code
Advantages
● Readable
● Understandable
● Less errors
● Easy to maintain ( fix, modify, learn, support)
● Testable
Hint: Time = Money

16. Clean Code
The cost of owning a mess
http://www.informit.com/articles/article.aspx?p=1235624&seqNum=3

17. Bad Code smells
Mostly found on legacy code
● No separation between PHP and HTML
● Lots of requires
● Global Variables
● No Database Abstraction Layer
http://www.sxc.hu/photo/967754

18. Bad Code smells
● Looks familiar ?

19. Meaningful Names
● Self explanatory
○ Variables, classes, functions
● Context aware
● Easy to understand by anyone
● No comments needed

20. Meaningful Names

21. Meaningful Names
1. Bad variable name $n
2. Bad variable name $t
3. Dispensable comments
4. Missing code indentation

22. Meaningful Names
1. Bad variable name $n
2. Bad variable name $t
3. Dispensable comments
4. Missing code indentation

23. Comments
The main purpose of comment is to explain
code.
Please don't use a comment when you can use a
function or variable.
Comments can contain lines

24. Comments Do's and don't

25. Comments Do's and don't
1. Localized comments and names
?
2. Comment adds nothing to the
code

26. Comments Do's and don't
1. Localized comments and names ?
2. Comment adds nothing to the
code

27. Comments Do's and don't
1. Inoffensive comments ?
2. Clear code to read ?

28. Comments Do's and don't
1. Inoffensive comments ?
2. Clear code to read ?
No comments needed !!!

29. Functions
● Small ( 1K lines of code is not small !!! )
● Do ONE thing
● Reduced number of arguments
● No side effects

30. Functions
Do ONE thing

31. Functions
Do ONE thing
Function purpose :
1. Return parts list
2. Maintain cache expiration
control ?

32. Functions
Do ONE thing
Function purpose :
1. Return parts list

33. Error Handling
1. Use Exceptions instead of returning values
for error handling
2. Don't return 'null'
3. Don't pass 'null'

34. Error Handling - Exceptions

35. Error Handling
Duplicate code

36. Error Handling
Duplicate code
Null values as error handling

37. Error Handling
No null returning values
Centralized error handling

38. Your best friends = Tools
PHPLOC by Sebastian Bergman
https://github.
com/sebastianbergmann/phploc
Quick analysis on the status of the code
Cyclomatic Complexity Analysis
Comment lines of code
Lines of code / Number of methods
... http://techportal.inviqa.com/2010/01/28/phploc-php-lines-of-code/

39. Your best friends = Tools
PHPMD by Manuel Pichler
http://phpmd.org/
Code Size Rules
Design Rules
Naming Rules
Unused Code Rules
Excessive Parameter List
...

40. Your best friends = Tools
PHP CodeSniffer
http://pear.php.net/package/PHP_CodeSniffer/
Helps you to keep your code readable.
http://techportal.inviqa.com/2009/10/12/usphp_code_sniffer/

41. How to keep your code clean ?
1. Refactor
2. Refactor
3. Refactor
4. Frequent Peer Reviews
5. Follow Naming Conventions
6. Don't comment and leave code behind, just
DELETE it
7. Use the tools often (PHPLOC, PHPMD, PHPCodeSniffer)
8. Keep your logs shell open all the time

42. Recap : Clean Code
What's clean code anyway ?
Formatted , Organized and Easy to read/modify

43. References
Clean Code by Hendrik Ebel
http://www.slideshare.net/hebel/clean-code
You code sucks, let's fix it by Rafael Dohms
http://www.slideshare.net/rdohms/bettercode-phpbenelux212alternate
Clean Code Barcelona 2009 by Jan W. Eshuis
http://www.slideshare.net/jwenl/clean-code-barcelona-2009
http://techportal.inviqa.com/2010/01/28/phploc-php-lines-of-code/

44. We're hiring
1. Back-end PHP Engineer
2. Front-end Engineer
3. Software Tester (QA)
4. System Administrator
If you are interested or know someone who, just contact me!
jose@guestcentric.com

45. Your time
Questions ? Comments ? Both ?
Thank you!
Feedback welcomed
https://joind.in/talk/view/8815
Twitter: josedasilva
Linkedin: linkedin.com/in/josedasilva
Email: josedasilva@gmail.com