README

A minimal PHP router for mapping request paths to class names.

Requirements

• PHP 8.0+

Installation

composer require coroq/router

Quick Start

<?php
use Coroq\Router\MapRouter;
use App\Middleware;
use App\Controller;

// Define a route map
$routeMap = [
    // Numeric keys always get included in results
    Middleware\Auth::class,

    // Empty string key matches root path
    '' => Controller\HomeController::class,

    // String keys map to path segments
    'users' => [
        // Nested numeric keys also get included
        Middleware\UserMiddleware::class,

        // Empty string key matches /users
        '' => Controller\User\ListController::class,

        // Nested paths
        'detail' => Controller\User\DetailController::class,
    ],
];

// Create router
$router = new MapRouter($routeMap);

// Get handlers for a path
$handlers = $router->routePath('/');
// Returns [Middleware\Auth::class, Controller\HomeController::class]

$handlers = $router->routePath('/users');
// Returns [Middleware\Auth::class, Middleware\UserMiddleware::class, Controller\User\ListController::class]

$handlers = $router->routePath('/users/detail');
// Returns [Middleware\Auth::class, Middleware\UserMiddleware::class, Controller\User\DetailController::class]

// Non-existent routes throw RouteNotFoundException
try {
    $handlers = $router->routePath('/nope');
} catch (Coroq\Router\RouteNotFoundException $e) {
    // Handle route not found
}

// Leading and trailing slashes are handled automatically
$handlers = $router->routePath('/users/detail/');  // Same as '/users/detail'

Concepts

The route map is a nested array structure:

• Numeric keys - Always included in results (middleware, shared handlers)
• String keys - Matched against path segments
• Empty string key ('') - Matches the current path level (e.g., / at root, /users inside 'users' array)
• Nested arrays - Represent path hierarchy

The router returns an array of all matched handlers in order, from root to leaf.

Fallback Routes

Use CatchAllRouter to handle any routes that don't match. Place it as a numeric-keyed item - it will be tried when no string keys match:

use Coroq\Router\CatchAllRouter;

$routeMap = [
    Middleware\Auth::class,
    '' => Controller\HomeController::class,
    'users' => [
        '' => Controller\User\ListController::class,
    ],
    // Catches any unmatched routes
    new CatchAllRouter(Controller\NotFoundController::class),
];

$router = new MapRouter($routeMap);
$handlers = $router->routePath('/unknown/path');
// Returns [Middleware\Auth::class, Controller\NotFoundController::class]

Path Rewriting

MapRouter matches path segments exactly as strings. When you need dynamic segments like /user/123 or /post/hello-world, use PathRewriter to extract parameters first, then route the normalized path.

$rewriter = new PathRewriter();
$rewriter->addRules([
    '/post/{postName}',
]);

// Rewrite extracts parameters and normalizes the path
$result = $rewriter->rewrite('/post/hello-world');
// $result->path   = '/post/postName'
// $result->params = ['postName' => 'hello-world']

// Route using the normalized path
$routeMap = [
    'post' => [
        'postName' => Controller\Post\ShowController::class,
    ],
];

$router = new MapRouter($routeMap);
$handlers = $router->routePath($result->path);

// Pass params to your controller however you like
// e.g., $controller->handle($request->withAttribute('params', $result->params));

Placeholder Types

Use type constraints to restrict what a placeholder matches:

$rewriter = new PathRewriter();
$rewriter->addRules([
    '/token/{value:hex}',           // matches /token/5f3a, not /token/xyz
    '/item/{id:uuid}',              // matches valid UUIDs only
    '/page/{name}',                 // matches any single segment (default type)
]);

Multiple Placeholders

Placeholders can appear multiple times in a path, or even within a single segment:

$rewriter = new PathRewriter();
$rewriter->addRule('/user/{userid:int}/post/{postid:int}');
// /user/42/post/99 → path: /user/userid/post/postid
//                    params: ['userid' => '42', 'postid' => '99']

$rewriter->addRule('/file/{name}.{ext}');
// /file/report.pdf → path: /file/name.ext
//                     params: ['name' => 'report', 'ext' => 'pdf']

$rewriter->addRule('/archive/{year:int}-{month:int}-{day:int}');
// /archive/2025-01-15 → path: /archive/year-month-day
//                        params: ['year' => '2025', 'month' => '01', 'day' => '15']

Rule Matching Order

Rules are applied sequentially. Each rule matches from the beginning of the path; remaining segments are preserved:

$rewriter = new PathRewriter();
$rewriter->addRule('/user/{userid:int}');

// /user/123/posts → path: /user/userid/posts, params: [userid => 123]
// The '/posts' suffix is preserved for further routing

Multiple rules can work together, with params accumulating:

$rewriter = new PathRewriter();
$rewriter->addRules([
    '/user/{userid:int}',
    '/user/userid/{action:alpha}',
]);

// /user/6755/edit
// → first rule: path becomes /user/userid/edit, params: [userid => 6755]
// → second rule: path becomes /user/userid/action, params: [userid => 6755, action => edit]

Custom Rules

For advanced matching, implement PathRewriteRuleInterface:

use Coroq\Router\PathRewrite\PathRewriteRuleInterface;
use Coroq\Router\PathRewrite\PathRewriteResult;

class RegexRule implements PathRewriteRuleInterface {
    public function apply(string $path): ?PathRewriteResult {
        if (preg_match('#^/legacy/(.+)/page(\d+)$#', $path, $m)) {
            return new PathRewriteResult('/legacy/item/page', [
                'item' => $m[1],
                'page' => $m[2],
            ]);
        }
        return null;
    }
}

$rewriter->addRule(new RegexRule());

PSR-15 Middleware Integration

The returned handler array can be used with PSR-15 middleware pipelines:

$result = $rewriter->rewrite($request->getUri()->getPath());
$handlers = $router->routePath($result->path);
// $handlers = [App\Middleware\Auth::class, App\Controller\User\ShowController::class]

// Build a middleware pipeline from $handlers
// Middleware passes to next; leaf controller returns response

Each leaf controller handles one route - no internal action dispatching.

License

MIT