A small vademecum for obsolete PHP 4 software migration.

1. PHP 4? OMG!
A small vademecum for obsolete software
migration.
Francesco Fullone, Ideato.it
ff AT ideato.it

2. Who am I
Francesco Fullone
- PHP developer since 1999
- GrUSP President
- PHP and Open Source Evangelist
- CEO @ Ideato.it
- Nerd and geek

3. How many of
you still use
PHP 4?

5. Do you know that the
official PHP 4 support has
ended on
8 August 2008?

7. Usage of PHP 4 (2008/10)
ph p 4 ph p 5
data from Nexen.net

9. The “Never touch a
running system” rule

10. “Why upgrade?
My servers work fine!”
But the hardware is
no longer supported
and the spare parts are
no longer available.

11. “Why upgrade?
My software works fine!”
But the dependencies
libraries are outdated
and no more developed.

12. “Why upgrade?
My code works fine!”
But the knowledge is
missed and the best
practice never applied.

13. Sometimes rewriting
from scratch is
not an option.

14. We need
a migration plan.
A good one.

15. Create Tests.

16. Create a tests suite:
A good test suite should be both Unit
and Functional.
At least we have to:
- test the core functionality (ie. Login)
- test the workflows
- test third party interaction
- test all the classes (if the code is OO)

17. Acceptance Tests:
If the code can't be
unit tested (phpUnit),
use acceptance tests
(Selenium-IDE).

18. Check for libs,
code smells and
dependancies.
Create Tests.

19. Check for libs, code smells and dependancies.
- <% ASP TAG?! %>
- Old global array $HTTP_*_VARS
- Magic Quotes
- Register Globals
- Safe mode
- Old PEAR/phpClasses classes
- Dismissed PHP_modules

20. #pear install PHP_CompatInfo

21. Rollback to the
default PHP.INI
Check for libs,
code smells and
dependancies.
Create Tests.

22. A lot of things changed in the PHP.INI, try to
use the default values during the upgrade
process.
Enable the LOG to the Notice level.

23. Upgrade PHP and the
system iteratively.
Rollback to the
default PHP.INI
Check for libs,
code smells and
dependancies.
Create Tests.

24. Read the LOG,
use the tests,
do code refactoring,
upgrade the system.

25. Repeat this mantra

26. THE END?

27. NO!

28. Now it's time to do
serious code refactoring:
- create proper unit tests
- use standard development pattern
- use an enterprise level framework
- remove unused modules

29. ?

30. Francesco Fullone
ff AT ideato.it
via Quinto Bucci 205
47023 Cesena (FC)
info AT ideato.it
www.ideato.it
www.fullo.net
www.grusp.it
www.phpday.it