An introduction to clean code and a guide to prevent software architecture and design flaws. Think on the kittens! Save them!

1. No more dead kittens
@yveshoppe

2. Disclaimer
The following presentation
contains violent scenes and
maybe not suitable for
children and kitten lovers.

3. The issue
During time the technical
debt in projects is rising and
preventing progress and
new features.
Start 2nd 3rd End

4. Why?
No Refactoring
Shortcuts
Hacks
Copy & Paste
Lack of time
// … tbc

6. The result:

7. How do you realize technical
debt?

8. Something easy gets painful
The fun is missing
At the beginning 10 minutes, now 10 hours

9. 5 Samples
5 Sins
5 Dead Kittens

10. Thank you Guido for your contribution!
Code-Style and Readability

11. More samples? Be prepared, it’s worse than these samples!
https://github.com/JoomTools/plg_content_jtcsv2html/blob/master/jtcsv2html.php

12. Rating

13. Readability
https://github.com/JoomTools
Communication is the key
Consistency
Clear rules for developers
Mistakes are easier noticed

14. Thank you Guido for your contribution!
Testability
protected function _validateField($field)
{
$index = $this->uParams['index'];
$data = $this->form[$this->uParams['theme'] . $index]->getData()->toArray();
$rule = false;
$value = '';
$showon = (string) $fie

15. if ($showon)
{
$_showon_value = explode(':', $showon);
$_showon_value[1] = JText::_($_showon_value[1]);
$showon_value = $this->form[$this->uParams['theme'] . $index]->getField($_showon_value[0])->value;
if ($_showon_value[1] != $showon_value)
{
$showField = false;
$valid = true;
$this->form[$this->uParams['theme'] . $index]->setValue($name, null, '');
if ($type == 'spacer')
{
$this->form[$this->uParams['theme'] . $index]->setFieldAttribute($name, 'label', '');
}
}
}
if (isset($data[$name]))
{
$value = $data[$name];
}
if ($required && !$value)
{
if (!$showField)
{
$validateField = false;
}
}
if ($validateField && $showField)
{
if ($type == 'file')
{
$jinput = JFactory::getApplication()->input;
$submitFiles = $jinput->files->get($this->uParams['theme'] . $index);
$issetFiles = false;
if (!empty($submitFiles[$name][0]['name']))
{
$issetFiles = true;
$files = $submitFiles[$name];

16. Rating

17. Testability
https://github.com/JoomTools
Avoid methods which are longer then the
screen (30-40 lines ++)
Complexity is rising exponentional
Not testable
Not reusable

18. Thank you Anonymous for your contribution!
Magic Numbers
$allpicsrandom = $params->get('allpicsrandom');
$allpics = $params->get('allpics');
$this->setImageProperties($images, $links_info);
if($allpicsrandom == 2 AND $allpics == 1)
{
$image = $images[0];
unset($images[0]);
}

19. What the f*** is 2?

20. Rating

21. Magic Numbers
https://github.com/...
Code should explain itself
and not hide between numbers
It’s magic! or 42
const DESCRIPTION = 2

22. Thank you Guido for contribution!
Commented and unused Code
<?php endif;
$countFieldsets++;
if ($countFieldsets % 2 || $countFieldsets >
$sumFieldsets) : ?>
<!--</div>-->
<?php endif;
endforeach;

23. ?!

24. Rating

25. Unused /
commented Code
https://github.com/...
Makes reading hard
Bloats up software
For that we have VCS (like Git)!
phpmd helps you finding unused
code!

26. Thank you Anonymous for your contribution!
Copy & Paste Code
$a = 23;
if ($a == 42)
for ($i = 0; $i < $a; $i++)
doSomething;
elseif (isArray($a))
for each ($a as $b)
doSame;
else

27. Rating

28. Copy & Paste
https://github.com/...
A kitten dies!
Changes need to happen on multiple
places
Error-proneness!
You don’t think! Coding is thinking!
phpcpd

29. The solution

30. Clean code
It is not enough
for the code to work
(Robert C. Martin)

31. Avoiding technical debt
Refactoring
Continuous refactoring
and reviewing.
Maintain your code
base!
Tests and TDD
(Automated) Tests help
us writing better and
reusable code
Philosophy
It’s not about code, it’s
about thinking and
honouring your own
work!

32. Clear dependencies

33. Why?
Dependencies have to be clearly defined (Testability)
Dependencies should not be created in methods, but in the constructor. So they
can easily exchanged against Mocks and Stubs
Single Responsibility

34. Test Driven
development
/ BDD

35. TDD / BDD
TDD / BDD help you thinking more on your
application and your code!
Business experience first
Gherkin
Clear definition of Requirements

36. Automated Testing

37. Putting tests
together to a big
automatic safety net!

38. Why automated testing?
Repeatable and scalable
Detect issues for every pull request
Saves time and helps you trusting your own code
Multiple PHP Versions, Browsers

39. Software used

40. 1000 things
more
KISS
DRY
CCD Werte
Furps
SMART
// …

41. Call for volunteers!
Joomla! is looking for new members, which want to make
Joomla! Better!
Joomla! Is more than just an CMS, it’s the love, the spirit 1000s
of people have put into it.

42. Questions?
Thank you for listening!
@yveshoppe