Načela čistog koda za XOOPS

Pregled

Čist kod je kod koji je jednostavan za čitanje, razumijevanje i održavanje. Ovaj vodič pokriva načela čistog koda posebno primijenjena na razvoj modula XOOPS.

Temeljna načela

mindmap
  root((Clean Code))
    Readability
      Meaningful Names
      Small Functions
      Comments When Needed
    Simplicity
      Single Responsibility
      DRY Principle
      KISS Principle
    Maintainability
      Consistent Style
      Error Handling
      Testing

Imena koja imaju smisla

Varijable

// Bad
$d = new DateTime();
$u = $memberHandler->getUser($id);
$arr = [];

// Good
$createdDate = new DateTime();
$currentUser = $memberHandler->getUser($userId);
$publishedArticles = [];

Funkcije

// Bad
function process($data) { ... }
function handle($item) { ... }
function doStuff($x, $y) { ... }

// Good
function publishArticle(Article $article): void { ... }
function calculateTotalPrice(array $items): float { ... }
function sendNotificationEmail(User $user, string $subject): bool { ... }

Nastava

// Bad
class Manager { ... }
class Helper { ... }
class Utils { ... }

// Good
class ArticleRepository { ... }
class NotificationService { ... }
class PermissionChecker { ... }

Male funkcije

Jedna odgovornost

// Bad - does too many things
function processArticle($data) {
    // Validate
    if (empty($data['title'])) {
        throw new Exception('Title required');
    }
    // Save
    $article = new Article();
    $article->setTitle($data['title']);
    $this->repository->save($article);
    // Notify
    $this->mailer->send($article->getAuthor(), 'Article published');
    // Log
    $this->logger->info('Article created');
    return $article;
}

// Good - each function does one thing
function validateArticleData(array $data): void
{
    if (empty($data['title'])) {
        throw new ValidationException('Title required');
    }
}

function createArticle(array $data): Article
{
    $this->validateArticleData($data);
    return Article::create($data['title'], $data['content']);
}

function publishArticle(Article $article): void
{
    $this->repository->save($article);
    $this->notifyAuthor($article);
    $this->logArticleCreation($article);
}

Duljina funkcije

Neka funkcije budu kratke - idealno ispod 20 redaka:

// Good - focused function
public function getPublishedArticles(int $limit = 10): array
{
    $criteria = new CriteriaCompo();
    $criteria->add(new Criteria('status', 'published'));
    $criteria->setSort('published_at');
    $criteria->setOrder('DESC');
    $criteria->setLimit($limit);

    return $this->repository->getObjects($criteria);
}

SUHO načelo (nemojte se ponavljati)

Ekstrakt zajedničkog koda

// Bad - repeated code
function getActiveUsers() {
    $criteria = new CriteriaCompo();
    $criteria->add(new Criteria('level', 0, '>'));
    $criteria->setSort('uname');
    return $this->userHandler->getObjects($criteria);
}

function getActiveAdmins() {
    $criteria = new CriteriaCompo();
    $criteria->add(new Criteria('level', 0, '>'));
    $criteria->add(new Criteria('is_admin', 1));
    $criteria->setSort('uname');
    return $this->userHandler->getObjects($criteria);
}

// Good - shared logic extracted
function getUsers(CriteriaCompo $criteria): array
{
    $criteria->add(new Criteria('level', 0, '>'));
    $criteria->setSort('uname');
    return $this->userHandler->getObjects($criteria);
}

function getActiveUsers(): array
{
    return $this->getUsers(new CriteriaCompo());
}

function getActiveAdmins(): array
{
    $criteria = new CriteriaCompo();
    $criteria->add(new Criteria('is_admin', 1));
    return $this->getUsers($criteria);
}

Rješavanje grešaka

Koristite iznimke ispravno

// Bad - generic exceptions
throw new Exception('Error');

// Good - specific exceptions
throw new ArticleNotFoundException($articleId);
throw new PermissionDeniedException('Cannot edit article');
throw new ValidationException(['title' => 'Title is required']);

Postupajte s pogreškama elegantno

public function findArticle(string $id): ?Article
{
    try {
        return $this->repository->findById($id);
    } catch (DatabaseException $e) {
        $this->logger->error('Database error finding article', [
            'id' => $id,
            'error' => $e->getMessage()
        ]);
        throw new ServiceException('Unable to retrieve article', 0, $e);
    }
}

Komentari

Kada komentirati

// Bad - obvious comment
// Increment counter
$counter++;

// Good - explains why, not what
// Cache for 1 hour to reduce database load during peak traffic
$cache->set($key, $data, 3600);

// Good - documents complex algorithm
/**
 * Calculate article relevance score using TF-IDF algorithm.
 * Higher scores indicate better match with search terms.
 */
function calculateRelevanceScore(Article $article, array $terms): float
{
    // ...
}

Organizacija koda

Struktura klase

class ArticleService
{
    // 1. Constants
    private const MAX_TITLE_LENGTH = 255;

    // 2. Properties
    private ArticleRepository $repository;
    private EventDispatcher $events;

    // 3. Constructor
    public function __construct(
        ArticleRepository $repository,
        EventDispatcher $events
    ) {
        $this->repository = $repository;
        $this->events = $events;
    }

    // 4. Public methods
    public function publish(Article $article): void { ... }
    public function archive(Article $article): void { ... }

    // 5. Private methods
    private function validateForPublication(Article $article): void { ... }
}

Kontrolni popis čistog koda

• Imena su smislena i izgovorljiva
• Funkcije rade samo jednu stvar
• Funkcije su male (< 20 redaka)
• Nema dupliciranog koda
• Ispravno rukovanje pogreškama uz posebne iznimke
• Komentari objašnjavaju “zašto”, a ne “što”
• Dosljedno oblikovanje i stil
• Nema čarobnih brojeva ili nizova
• Ovisnosti se ubacuju, a ne stvaraju

Povezana dokumentacija

• Organizacija koda
• Rješavanje grešaka
• Testiranje najboljih praksi
• Standardi PHP