KaririCode ClassDiscovery

PHP 8.4+ class discovery — token-based scanning, attribute automation, multi-tier caching and dependency analysis.

Discover controllers, services, and event listeners automatically — without loading a single class.

Installation · Quick Start · Use Cases · Scanners · Caching · CI Integration

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The Problem

Modern PHP applications rely on convention over configuration — routes registered from #[Route], services injected from #[Service], listeners wired from #[EventListener]. Without a discovery engine, teams end up writing this manually:

// routes.php — manually maintained, drifts over time
Router::get('/users', [UserController::class, 'index']);
Router::post('/users', [UserController::class, 'store']);
Router::get('/products', [ProductController::class, 'index']);
// ... 300 more lines

And for services:

// bootstrap.php — duplicated, error-prone
$container->bind(MailerService::class, MailerService::class);
$container->bind(PaymentService::class, PaymentService::class);
// ... one entry per class forever

The Solution

composer require kariricode/class-discovery

use KaririCode\ClassDiscovery\Filter\AttributeFilter;
use KaririCode\ClassDiscovery\Scanner\{ComposerNamespaceResolver, FileScanner};

$scanner = new FileScanner(new ComposerNamespaceResolver());
$scanner->addFilter(new AttributeFilter(Route::class));

// Discovers and returns all #[Route]-annotated controllers — instantly
$result = $scanner->scan(['src/Controller']);

One scan replaces hundreds of manual registrations. Results are immutable, cacheable, and resolved in 30–80ms cold / <3ms warm.

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Requirements

Requirement	Version
PHP	8.4 or higher
Composer	2.x

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Installation

composer require kariricode/class-discovery

Optional integrations:

composer require kariricode/cache                   # PSR-16 cache backend
composer require kariricode/configurator            # Environment-aware configuration
composer require kariricode/dependency-injection    # PSR-11 container

---

Quick Start

1 — Discover all classes

use KaririCode\ClassDiscovery\Scanner\{ComposerNamespaceResolver, FileScanner};

$scanner = new FileScanner(new ComposerNamespaceResolver());
$result  = $scanner->scan(['src/']);

foreach ($result as $fqcn => $metadata) {
    echo "{$fqcn} — {$metadata->filePath}\n";
}

echo "Found " . $result->count() . " classes in "
   . round($result->getScanDuration() * 1000, 1) . "ms\n";

2 — Filter by attribute

use KaririCode\ClassDiscovery\Filter\AttributeFilter;

$scanner->addFilter(new AttributeFilter(Route::class));
$result = $scanner->scan(['src/Controller']);

3 — Enable caching

use KaririCode\ClassDiscovery\Cache\{ChainCacheStrategy, FileCacheStrategy, MemoryCacheStrategy};

$cache = new ChainCacheStrategy(
    new MemoryCacheStrategy(),
    new FileCacheStrategy('/var/cache/discovery'),
);

$scanner->setCacheStrategy($cache);
$result = $scanner->scan(['src/']);  // cold: ~60ms · warm: <2ms

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Real-world Use Cases

HTTP Router — auto-register controllers from #[Route]

#[\Attribute(\Attribute::TARGET_CLASS | \Attribute::TARGET_METHOD)]
final readonly class Route
{
    public function __construct(
        public readonly string $path,
        public readonly string $method = 'GET',
    ) {}
}

// Discovery
$scanner = new FileScanner(new ComposerNamespaceResolver());
$scanner->addFilter(new AttributeFilter(Route::class));
$result  = $scanner->scan(['src/Controller']);

foreach ($result as $fqcn => $metadata) {
    $router->mount($fqcn);  // class-level #[Route]

    foreach ($metadata->methods as $method) {
        if ($method->hasAttribute('Route')) {
            // Use ReflectionScanner to read path / method values
        }
    }
}

---

DI Container — auto-register services from #[Service]

$scanner = new FileScanner(new ComposerNamespaceResolver());
$scanner->addFilter(new AttributeFilter(Service::class));
$scanner->setCacheStrategy($cache);  // warm: <2ms

$result = $scanner->scan(['src/Service', 'src/Repository']);

foreach ($result as $fqcn => $metadata) {
    $container->bind($fqcn, $fqcn);  // zero manual registration
}

---

Event Dispatcher — auto-wire listeners from #[EventListener]

use KaririCode\ClassDiscovery\Scanner\ReflectionScanner;

// ReflectionScanner reads actual attribute constructor values
$scanner = new ReflectionScanner(new ComposerNamespaceResolver());
$scanner->addFilter(new AttributeFilter(EventListener::class));
$result  = $scanner->scan(['src/Listener']);

foreach ($result as $fqcn => $metadata) {
    foreach ($metadata->attributes as $attrMeta) {
        if ($attrMeta->instance instanceof EventListener) {
            $dispatcher->listen(
                event   : $attrMeta->instance->event,
                listener: $fqcn,
                priority: $attrMeta->instance->priority,
            );
        }
    }
}

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Plugin System — discover extensions by interface

use KaririCode\ClassDiscovery\Filter\InterfaceFilter;

$scanner = new FileScanner(new ComposerNamespaceResolver());
$scanner->addFilter(new InterfaceFilter(PaymentGatewayInterface::class));

$result = $scanner->scan(['plugins/']);

foreach ($result as $fqcn => $metadata) {
    $registry->register(new $fqcn());
}

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Refactoring Guard — detect circular dependencies

use KaririCode\ClassDiscovery\Analyzer\{CircularDetector, DependencyAnalyzer};

$scanner  = new FileScanner(new ComposerNamespaceResolver());
$result   = $scanner->scan(['src/']);

$detector = new CircularDetector(
    new DependencyAnalyzer(),
    throwOnDetection: true,  // throws DiscoveryException::circularDependency()
);

$cycles = $detector->check($result);
// [['App\A', 'App\B', 'App\C', 'App\A']]

---

Console — auto-register commands from #[Command]

use KaririCode\ClassDiscovery\Filter\{AttributeFilter, NamespaceFilter};

$scanner = new FileScanner(new ComposerNamespaceResolver());
$scanner->addFilter(new AttributeFilter(Command::class));
$scanner->addFilter(new NamespaceFilter('App\\Console\\Command'));

$result = $scanner->scan(['src/Console']);

foreach ($result as $fqcn => $metadata) {
    $application->add(new $fqcn());
}

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Scanner Comparison

Scanner	Parser	Loads Classes	Performance*	Best For
FileScanner	token_get_all	❌ Never	30–80ms cold / <3ms warm	General listing, attribute names
AttributeScanner	FileScanner + filter	❌ Never	50–100ms cold / <5ms warm	Attribute-driven discovery
DirectoryScanner	FileScanner + constraints	❌ Never	dep. on I/O	Depth/pattern-bounded scan
ReflectionScanner	ReflectionClass	✅ Required	300–800ms	Full attribute argument values

*per 1,000 classes — with cache, warm scans are typically 5–10× faster

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Filters

use KaririCode\ClassDiscovery\Filter\{
    AttributeFilter,
    InterfaceFilter,
    NamespaceFilter,
    StructuralFilter,
    CompositeFilter,
};

// By attribute (OR — multiple attribute classes)
$scanner->addFilter(new AttributeFilter(Route::class, Command::class));

// By implemented interface
$scanner->addFilter(new InterfaceFilter(HandlerInterface::class));

// By namespace prefix
$scanner->addFilter(new NamespaceFilter('App\\Handler'));

// By structural characteristics
$scanner->addFilter(new StructuralFilter(isFinal: true, isReadonly: true));

// OR-logic composite (attribute OR interface)
$scanner->addFilter(new CompositeFilter(
    requireAll: false,
    new AttributeFilter(Route::class),
    new InterfaceFilter(ControllerInterface::class),
));

---

Caching

use KaririCode\ClassDiscovery\Cache\{
    ChainCacheStrategy,     // L1 → L2 chain with automatic promotion
    FileCacheStrategy,      // Atomic writes (temp → rename), OPcache-friendly
    MemoryCacheStrategy,    // In-process, process-lifetime
};

// Multi-tier: Memory (L1) → File (L2)
$cache = new ChainCacheStrategy(
    new MemoryCacheStrategy(defaultTtl: 60),
    new FileCacheStrategy('/var/cache/discovery', defaultTtl: 3600),
);

$scanner->setCacheStrategy($cache);

// First request  : hits filesystem (~60ms)
// Every request after: hits memory   (<1ms)
$result = $scanner->scan(['src/']);

---

PSR-11 Container Registration

use KaririCode\ClassDiscovery\Integration\PSR11Integration;
use KaririCode\ClassDiscovery\Contract\{Scanner, AttributeScanner};

$container->singleton(
    Scanner::class,
    fn () => PSR11Integration::createDefaultScanner($cache),
);

$container->singleton(
    AttributeScanner::class,
    fn () => PSR11Integration::createAttributeScanner($cache),
);

---

Error Handling

use KaririCode\ClassDiscovery\Exception\DiscoveryException;

try {
    $result = $scanner->scan(['/path/that/does/not/exist']);
} catch (DiscoveryException $e) {
    match ($e->getCode()) {
        1001 => handlePathNotFound($e),
        1002 => handlePathTraversal($e),
        1003 => handleSymlinkEscape($e),
        1004 => handleMaxDepthExceeded($e),
        1005 => handleMaxFilesExceeded($e),
        1010 => handleCircularDependency($e),
        default => throw $e,
    };
}

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CI Integration

GitHub Actions — unified pipeline

name: Quality
on: [push, pull_request]
jobs:
  quality:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: shivammathur/setup-php@v2
        with:
          php-version: '8.4'
          coverage: pcov
      - run: composer install --no-progress --no-scripts
      - run: vendor/bin/kcode init
      - run: vendor/bin/kcode quality

GitHub Actions — parallel jobs

jobs:
  cs-check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: shivammathur/setup-php@v2
        with: { php-version: '8.4' }
      - run: composer install --no-progress --no-scripts
      - run: vendor/bin/kcode init && vendor/bin/kcode cs:fix --check

  analyse:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: shivammathur/setup-php@v2
        with: { php-version: '8.4' }
      - run: composer install --no-progress --no-scripts
      - run: vendor/bin/kcode init && vendor/bin/kcode analyse

  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: shivammathur/setup-php@v2
        with: { php-version: '8.4', coverage: pcov }
      - run: composer install --no-progress --no-scripts
      - run: vendor/bin/kcode init && vendor/bin/kcode test

---

Architecture

Component layout

src/
├── Contract/      7 interfaces (ISP-compliant)
├── Scanner/       5 implementations (composition pattern)
├── Result/        5 final readonly DPOs (ARFA 1.3 P1)
├── Filter/        5 composable predicates (AND/OR)
├── Cache/         3 cache strategies (Chain, Memory, File)
├── Analyzer/      2 analyzers (dependency graph + DFS cycle detection)
├── Integration/   3 bridges (PSR-16, PSR-11, Configurator)
├── Enum/          2 PHP 8.1 enums (backed + pure)
└── Exception/     1 exception class, 10 named constructors

Key design decisions

Decision	Rationale	ADR
Token-based parsing	Never loads or executes discovered classes	ADR-001
Zero external dependencies	Works in any PHP 8.4 project, no version conflicts	ADR-002
Immutable result objects	Thread-safe, cacheable, ARFA 1.3 compliant	ADR-003
Composition over inheritance	Scanners compose FileScanner; no deep hierarchies	ADR-005
Multi-tier cache strategy	Memory (L1) → File (L2), 5–10× warm speedup	ADR-006

Specifications

Spec	Covers
SPEC-001	Component architecture, contracts, scanner strategies

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Project Stats

Metric	Value
PHP source files	33
Total source lines	~2,800
External runtime dependencies	0
Filter types	5 (Attribute, Interface, Namespace, Structural, Composite)
Scanner strategies	4 (File, Attribute, Directory, Reflection)
Cache strategies	3 (Memory, File, Chain)
PHPStan level	9 (0 errors)
Psalm level	3 (0 errors)
Test suite	222 tests · 440 assertions
Line coverage	95.44%
PHP version	8.4+
ARFA compliance	1.3

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KaririCode Ecosystem Integration

Component	Attributes Discovered
kariricode/router	#[Route], #[Middleware], #[Guard]
kariricode/console	#[Command], #[Argument], #[Option]
kariricode/dependency-injection	#[Singleton], #[Scoped], #[Tagged]
kariricode/event-dispatcher	#[EventListener], #[EventSubscriber]
kariricode/websocket	#[WebSocketRoute], #[OnConnect], #[OnMessage]
kariricode/i18n	#[TranslatableResource]

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Contributing

git clone https://github.com/kariricode/class-discovery.git
cd class-discovery
composer install
vendor/bin/kcode init
vendor/bin/kcode quality   # Must pass before opening a PR

CI enforces code quality (PHPStan level 9, Psalm, CS-Fixer, PHPUnit) on every push and PR.

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License

MIT License © Walmir Silva

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Part of the KaririCode Framework ecosystem.

kariricode.org · GitHub · Packagist