Clean Code
By Joeri Timmermans
Hi, I’m Joeri!
34 years old
Gaming, food, reading, education
Accountancy – Informatics
Interactive Multimedia Design
Developer
Project Manager
Learn & Development Manager
(1999 – 2007)
(2017 - 2021)
(2011 - 2017)
(2007 - 2011)
(2021 - now)
/in/joeri-timmermans
www.joeritimmermans.be
@joeri_timmer
hello@joeritimmermans.be
Joined Nov 2014
Campuses
/company/iodigital-com
www.iodigital.com
@iodigital_com
Here to help you grow
Stimulating
talent growth
Shaping campuses
In-depth expertise
/company/iodigital-com
www.iodigital.com
@iodigital_com
How did I end up here?
Blogging
https://coderwall.com/pix-art
Year 2012
https://www.pix-art.be
Year 2014
https://www.joeritimmermans.be
Year 2020
Public speaking
Interaction loading!
Interaction loading!
Interaction loading!
Interaction loading!
Always code as if the person who ends up maintaining your code is a violent psychopath who knows where you live.
- John F. Woods, September 1991
Interaction loading!
Real life example 😢
The moment you're presented with a problem you have to solve, it's your duty to do this in the best possible way.
- Me,
Interaction loading!
The ratio of time spent reading versus writing is well over 10 to 1. Making it easy to read code makes it easier to write.
- Robert C. Martin, Clean Code
6 steps
to clean coding
Step 1
Understanding
Interaction loading!
Documentation
Pen & Paper
ERD Schema
Flowchart
Step 2
Writing
Organising
Simple
Complex
VS
Our own festival!
- Valid invitation
- User already signed up
- Destroy invitation
- Sign up user
Commenting/Pseudocode
class EventService {
...
public function signUp(Invitation $invite, User $user)
{
// 1. Check if the invitation is valid
// 2. Check if the user already signed up for the event
// 3. Register the invitation
// 4. Sign the user up for the event
// 5. Return signup
}
...
}Naming
class EventService {
...
public function signUp(Invitation $invite, User $user)
{
$this->guardThatInvitationIsValid($invite);
$event = $invite->getEvent();
$this->guardThatUserIsNotSignedUp($user, $event);
$this->invitationService->register($user, $invite);
$signUp = new SignUp($user, $event);
$event->addSignUp($signUp);
return $signUp;
}
...
}Indenting
class EventController {
...
public function signUpAction(Invitation $invite, User $user)
{
try {
$signup = $this->eventService->signUp($invite, $user);
} catch (GuardException $e) {
return View::create($e->getMessage(), 403);
} catch (ErrorException $e) {
return View::create($e->getMessage(), 400);
}
return View::create($signup, 200);
}
...
}Think positive negative
function writeFile($fullpath, $content)
{
if (is_writable($fullpath)) {
if ($fp = fopen($fullpath,'w')) {
if (fwrite($fp,$content)) {
// ...
} else {
return false;
}
} else {
return false;
}
} else {
return false;
}
}function writeFile($fullpath, $content)
{
if (!is_writable($fullpath)) {
return false;
}
if (!$fp = fopen($fullpath,'w')) {
return false;
}
if (fwrite($fp,$content)) {
return true;
}
return false;
}Bad example
Good example
Write a file
- Check if writing is allowed
- Open the file
- Write content
Step 3
Principles
Interaction loading!
Don't repeat yourself (DRY)
class ExampleService
{
public function doThis(Example $example)
{
if (!$example->isAwesome()) {
throw new NotAwesomeException("This is not an awesome example!");
}
//Do this
}
public function doThat(Example $example)
{
if (!$example->isAwesome()) {
throw new NotAwesomeException("This is not an awesome example!");
}
//Do that
}
}Bad example
Don't repeat yourself (DRY)
class ExampleService
{
public function doThis(Example $example)
{
$this->isAwesomeExample($example);
//Do this
}
public function doThat(Example $example)
{
$this->isAwesomeExample($example);
//Do that
}
private function isAwesomeExample(Example $example)
{
if (!$example->isAwesome()) {
throw new NotAwesomeException("This is not an awesome example!");
}
}
}Good example
Keep it simple stupid (KISS)
class EventService {
...
public function signUp(Invitation $invite, User $user)
{
if ($invite->hasBeenUsed() && $invite->hasCorrectDate() && $invite->isValid()) {
$event = $invite->getEvent();
if ($this->checkIfUserIsSignedup($user, $event)) {
$this->invitationService->register($user, $invite);
$signUp = new SignUp($user, $event);
$event->addSignUp($signUp);
} else {
throw new AlreadySignedupException();
}
} else {
throw new InvalidInvitationException();
}
return $signUp;
}
...
}Bad example
Keep it simple stupid (KISS)
class EventService {
...
public function signUp(Invitation $invite, User $user)
{
$this->guardThatInvitationIsValid($invite);
$event = $invite->getEvent();
$this->guardThatUserIsNotSignedUp($user, $event);
$this->invitationService->register($user, $invite);
$signUp = new SignUp($user, $event);
$event->addSignUp($signUp);
return $signUp;
}
...
}Good example
Boy Scout Rule
“Always leave the campground cleaner than you found it.”
Step 4
Tools
Interaction loading!
Git
A tool that helps users control their code, from small to large projects and team collaboration
/git/git
PHP MD
A tool that looks for potential
problems in your code.
/phpmd/phpmd
PHPSTAN
A static analysis tool
to discover bugs in your code without running it.
/phpstan/phpstan
GrumPHP
A tool that creates a git hook
and does a list of checks before you can commit.
/phpro/grumphp
PHPCS Fixer
A tool created by Sensiolabs to fix most violations against the PHP PSR-1 and PSR-2 standards.
/FriendsOfPHP/PHP-CS-Fixer
Step 5
Experimenting
Exploring
My Blog 🤓
Testing
$ vendor/bin/behat
Feature: pagevisit
This is a standard behat test to see if the
given page is visited and show the right content
Scenario: When i visit the school i should see things
# features/pagevisit.feature:4
Given I am on "school"
# FeatureContext::visit()
Then I should see "Good students"
# FeatureContext::assertPageContainsText()
Then I should see "Interesting topics"
# FeatureContext::assertPageContainsText()
1 scenario (1 passed)
3 steps (3 passed)
0m7.77s (13.74Mb)Step 6
Practicing
Being a good developer,
is an art
3 Tips
- It's a lifestyle
- Be your own critic, and identify mistakes
- Read (Books, blogs, ...)